Download Surveys of Species at Risk and their Associated Habitats in the

Surveys of Species at Risk and their Associated Habitats
in the Clowhom Watershed – Year 1
FWCP Project No. 13.W.COM.01
Final Report - July 2014
Prepared for: Fish and Wildlife Compensation Program
6911 Southpoint Drive, Burnaby, BC, V3N 4X8
Prepared by:
Michelle Evelyn and David Stiles, Project Leaders
Halcyon Professional Services & Sunshine Coast Wildlife Project
650 Gower Point Road, Gibsons, BC, V0N 1V8
Chris Currie
25931 Dewdney Trunk Road, Maple Ridge, BC, V4R 1Y3
Aimee Mitchell
Athene Ecological, 103-1516 East 1st Avenue, Vancouver, BC, V5N 1A5
Prepared with financial support of the Fish and Wildlife Compensation Program on behalf of its program
partners BC Hydro, the Province of BC, Fisheries and Oceans Canada, First Nations and the public
EXECUTIVE SUMMARY
Wetlands and riparian areas are essential to a multitude of wildlife species. These fragile and ecologically
important ecosystems are also among those most affected by dam construction and hydro operations. On the
Sunshine Coast, the installation of BC Hydro’s Clowhom Dam in the 1950s flooded two existing lakes to
create Clowhom Reservoir, resulting in the loss of lowland riparian forests and wetlands. There is an urgent
need to map and assess remaining wetland and riparian areas in the Clowhom watershed, survey associated
species at risk, and identify and carry out restoration and enhancement activities to benefit these habitats and
species. To this end, “riparian and wetland mapping and restoration” and “amphibian surveys” have been
identified as two of the five top priorities for FWCP funding in the Clowhom Basin.
This report describes the first year of a multi-year project in the Clowhom watershed. Our objectives are: (1)
to identify, assess and map wetlands and riparian ecosystems; (2) to undertake comprehensive surveys of
species at risk and their critical habitat; (3) to work with partners to develop, implement, monitor and
adaptively manage multi-species restoration, management and enhancement plans; and (4) to carry out an
active outreach, education and community engagement program. Through these activities we aim to identify
sensitive habitats; locate new occupied sites for threatened and endangered species; highlight sites of future
inventory activities; identify opportunities and prioritize areas for habitat restoration, enhancement,
conservation, and threat mitigation; increase and improve habitat for wildlife; reduce direct threats to
populations of species at risk; increase community participation in wildlife and habitat stewardship activities;
and improve awareness of the Fish and Wildlife Compensation Program and its program partners.
Field survey activities carried out between April 2013 and March 2014 included locating, mapping and
assessing 14 wetlands; conducting 95 owl call-playbacks surveys; carrying out turtle basking surveys and
habitat assessments along 27 km of shoreline habitat; and undertaking 144 person hours of amphibian egg
mass, perimeter, auditory and road surveys, along with 84 trap nights of amphibian live trapping.
Because of Clowhom’s steep slopes and narrow valley bottom, wetland habitats in the watershed are very
limited in scope and abundance. There was likely a substantial loss of lowland wetland and riparian habitats
when the lower valley was flooded with the construction of the Clowhom dam. The most common type of
wetlands in the watershed are swamps less than a hectare in size. Most of these have been created by
beaver activity, which is essential for the existence of diverse wetland habitats in the area. Other small
swamps have been created by roads impounding water in shallow pools that eventually drain into the
Clowhom River mainstem through culverts and small stream channels.
The largest wetland is a 33 hectare complex at the end of the reservoir which incorporates many different
wetland classes, including small areas of bog, swamp and shallow water within the dominant fen and marsh
communities. This site is representative of the type of habitat that would likely have existed prior to the
construction of the reservoir. It includes both stable, natural wetlands, and areas where the wetland habitat is
greatly influenced by the dramatic, unnatural, and unpredictable raising and lowering of reservoir water levels.
This wetland complex is extremely important to wildlife in the watershed, providing highly productive habitat
for a wide range of species, from large vertebrates, to small invertebrates, including at least four species at
risk. Turning this site into a provincial Wildlife Management Area could provide extra management options,
while still permitting hunting and hydro activity.
Our amphibian surveys documented the presence of at least seven amphibian species in the Clowhom
watershed, including two species at risk. We located three breeding locations for Western Toads, the first
such sites confirmed on the Lower Sunshine Coast for this imperilled species. We pinpointed two breeding
sites for blue-listed Red-legged Frogs. Numbers of these frogs appear to be far lower than in other areas of
the Sunshine Coast, and observed egg masses were half the normal size. Our owl surveys established the
presence of at least three owl species, including federally threatened and provincially blue-listed Western
Screech-Owls, all found in mixed riparian forest at elevations of 103 meters or lower, along the reservoir and
Clowhom River. In all, this project year, we documented the presence of 66 vertebrate species in Clowhom
watershed, including seven species at risk. Despite exhaustive surveys, there was no evidence that Western
Painted Turtles occupy the watershed.
Clowhom Watershed Species at Risk and Habitat Surveys
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Many of the Clowhom wetlands have been impacted by humans. One problematic issue facing some of these
wetlands and their species are the unnatural and unpredictable fluctuations in water levels with hydro
activities. Fluctuating water levels in wetlands immediately adjacent to the reservoir limit reproduction and
recruitment of amphibians in these areas (Wetlands 9 and 10). Rapid decreases in water levels can strand
amphibian egg masses on land, killing them, while low water levels can cause breeding pools to dry up before
larvae can metamorphose. Rapid inundation can wash egg masses away, decrease water temperatures
hindering development, and substantially increase predation risk by allowing fish to enter the fish-free sites
where amphibians prefer to breed. An analysis of reservoir levels would help us to assess impacts of water
level fluctuations on breeding amphibians, and to enable development of management recommendations
related to timing, frequency and duration of inundation of specific elevations.
To mitigate the impact of water level fluctuations on breeding amphibians, it may be possible to create stable
habitats that will not be subject to the same deleterious effects experienced by areas directly connected to the
reservoir. Ponds of various sizes could potentially be constructed in wetlands and riparian areas adjacent to
those currently being affected. An analysis of the soils and hydrology of specific areas is recommended to
help determine the feasibility and logistics of this habitat enhancement activity.
Wildlife in the Clowhom watershed are also impacted by transmission lines, which cross at least seven
wetlands, and by roads, which run adjacent to several important habitats. Threats to wildlife at these sites
include road mortality, pollution from road runoff, introduction of invasive species, and impacts from right of
way maintenance, brushing, and vegetation removal. At Wetland 7, an important high density breeding site
for Western Toads is right next to the road (Clowhom Main km 17). We recommend temporary road signage
at this site to raise awareness of the presence and season of toad metamorphosis and migration. In the
longer term, further mitigation measures, such as drift fences and a crossing structure, should be investigated.
Maintenance of hydro right of ways that pass through wetlands should be timed to avoid critical
developmental periods for amphibians, and chemical herbicides should be avoided in these sites. Other
management recommendations for specific wetlands include monitoring of the spread of invasive species to
determine if removal is necessary, undertaking riparian planting to decrease pollution from road runoff, and
installing woody debris to improve amphibian habitat.
Several species at risk, including Western Screech-Owls, are associated with mature forest and related
mature forest structural features. Suitable late successional forest habitat is limited in the watershed due to
past logging activity. Future forest harvest decisions should seek to conserve and maintain habitat values for
listed wildlife species around important breeding, hibernating, nesting and foraging sites and within identified
territories. For Screech-Owls, it is essential to maintain areas of low elevation late successional riparian forest
and the large diameter cavity-forming trees necessary for nesting. For Red-legged Frogs along with other
amphibian species, it is vital to conserve forested areas adjacent to their breeding ponds. The patch of
mature riparian forest adjacent to Wetland 6 (Clowhom Main km 18.5) is especially valuable to wildlife.
In addition to field survey activities, we also carried out an active public engagement program to increase
community participation in wildlife conservation and stewardship efforts and increase awareness of issues
facing species at risk. Activities included making presentations, providing school programs, hosting outreach
tables, working with community members to build and install bat and owl houses, encouraging landowners to
sign wildlife stewardship agreements, creating interpretive signs, and providing information and recruiting
participation through media articles, newsletters, website and Facebook posts. In all, we carried out 45 public
engagement events this project year, reaching over 2200 community members of all ages. Over 200 people
signed stewardship agreements to maintain over 200 hectares of wildlife habitat.
Our work in the Clowhom watershed will continue in 2014-2015. Planned activities for Year 2 include:
continuing to evaluate wildlife habitat, assess threats, and identify priority areas and actions for habitat
conservation, restoration, enhancement and threat mitigation; continuing to survey wetlands, amphibians and
owls; continuing with our public education and engagement program; assessing riparian habitat in the
watershed using a GIS approach; and undertaking new surveys to identify occupied sites and evaluate habitat
for additional species at risk (Northern Goshawks, Pacific Water Shrews, Coastal Tailed Frogs, and bats).
Based on the information from our habitat and wildlife surveys, we will continue to work with project partners
to develop and implement comprehensive, multi-species habitat restoration and enhancement plans that will
help mitigate direct threats to populations, and increase and improve habitat for wildlife species in the
Clowhom Basin.
Clowhom Watershed Species at Risk and Habitat Surveys
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TABLE OF CONTENTS
EXECUTIVE SUMMARY ......................................................................................................................................2
1.0 INTRODUCTION ............................................................................................................................................7
2.0 GOALS AND OBJECTIVES ...........................................................................................................................7
3.0 STUDY AREA .................................................................................................................................................8
4.0 METHODS ................................................................................................................................................... 10
4.1 Wetland Mapping and Assessment ......................................................................................................... 10
4.2 Amphibian Surveys .................................................................................................................................. 11
4.3 Turtle Surveys.......................................................................................................................................... 13
4.4 Owl Surveys............................................................................................................................................. 14
4.5 Public Outreach and Engagement .......................................................................................................... 15
4.6 Owl Habitat Enhancement ....................................................................................................................... 18
5.0 RESULTS .................................................................................................................................................... 20
5.1 Wetlands .................................................................................................................................................. 20
5.2 Amphibians .............................................................................................................................................. 47
5.3 Turtles ...................................................................................................................................................... 57
5.4 Owls ......................................................................................................................................................... 57
5.5 Other Wildlife ........................................................................................................................................... 59
6.0 DISCUSSION .............................................................................................................................................. 61
6.1 Wetlands .................................................................................................................................................. 61
6.2 Amphibians .............................................................................................................................................. 63
6.3 Turtles ...................................................................................................................................................... 67
6.4 Owls ......................................................................................................................................................... 68
6.5 Other Species at Risk .............................................................................................................................. 69
6.6 Planned Activities for Year 2 of this Project ............................................................................................ 70
7.0 RECOMMENDATIONS ............................................................................................................................... 71
8.0 ACKNOWLEDGEMENTS............................................................................................................................ 78
9.0 REFERENCES ............................................................................................................................................ 79
10.0 CONFIRMATION OF FWCP RECOGNITION........................................................................................... 82
11.0 APPENDICES ........................................................................................................................................... 87
Appendix 1: Data Collected during Comprehensive Wetland Surveys ......................................................... 87
Appendix II: Qualitative Wetland Evaluation Rankings ................................................................................. 88
Appendix III: Wetland Plant Lists for Clowhom Wetlands ............................................................................. 90
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LIST OF FIGURES
Figure 1: Location of Clowhom Watershed, Sunshine Coast, BC........................................................................8
Figure 2: Locations of Survey Activities in the Clowhom Watershed, Year 1 (2013-2014)..................................9
Figure 3: Assessing Wetlands in the Clowhom Watershed .............................................................................. 10
Figure 4: Amphibian Egg Mass Perimeter Survey ............................................................................................ 11
Figure 5: Live Trapping Aquatic Amphibians Using Funnel Traps .................................................................... 12
Figure 6: Conducting Western Screech-Owl Call-Playback Surveys ................................................................ 14
Figure 7: Public Outreach Tables, Presentations, and School Programs ......................................................... 15
Figure 8: Owl and Amphibian Interpretive Signs ............................................................................................... 17
Figure 9: Community Members of All Ages Help to Build Owl Nest Boxes....................................................... 18
Figure 10: Installing Screech-Owl Nest Boxes in the Clowhom Watershed ..................................................... 19
Figure 11: Locations of Mapped Wetlands in the Clowhom Watershed ........................................................... 20
Figure 12: Wetland 1, One of Three Small Swamps Near km 23 Clowhom Main FSR .................................... 23
Figure 13: Wetland 3, One of Three Small Swamps Near km 23 Clowhom Main FSR .................................... 23
Figure 14: Location, Classification and Mapping of Wetlands 1, 2 and 3 ......................................................... 24
Figure 15: Wetland 4, a Small Beaver Swamp Near km 20 Clowhom Main FSR ............................................. 25
Figure 16: Location, Classification and Mapping of Wetlands 4 and 5 ............................................................. 26
Figure 17: Wetland 5, a Swamp/Marsh Complex between Clowhom River & Clowhom Main FSR ................. 27
Figure 18: Wetland 6, a Small Swamp near km 18.5 Clowhom Main FSR ....................................................... 28
Figure 19: Location, Mapping and Classification of Wetland 6 ......................................................................... 29
Figure 20: Fen / Swamp Area of Wetland 7 on East Side of the Road ............................................................. 31
Figure 21: Riparian Flood Plain Area of Wetland 7 on West Side of Road ....................................................... 31
Figure 22: Location, Mapping and Classification of Wetland 7 ......................................................................... 32
Figure 23: Fen Area of Wetland 8 ..................................................................................................................... 34
Figure 24: Bog Area of Wetland 8 ..................................................................................................................... 34
Figure 25: Location, Mapping and Classification of Wetlands 8 and 9 ............................................................. 35
Figure 26: Marsh Portion of Wetland 9, where Western Toad Tadpoles were Found ...................................... 36
Figure 27: Western Toad Egg Strings at Wetland 10 ........................................................................................ 37
Figure 28: Location, Mapping and Classification of Clowhom Wetland 10 ....................................................... 38
Figure 29: Water Level Fluctuations at Wetland 10 (June 2013 above, Sept 2013 below) .............................. 39
Figure 30: Wetland 11, a Small Swamp / Fen Complex near km 4 Bear Creek FSR ....................................... 40
Figure 31: Location, Mapping and Classification of Wetlands 11 and 12 ......................................................... 41
Figure 32: Wetland 12, a Manmade Series of Ponds Constructed by Bear Creek Hydro ................................ 42
Figure 33: Wetland 13, a Riparian Flood Plain / Swamp Complex near km 6 Bear Creek FSR....................... 43
Figure 34: Location, Classification and Mapping of Wetland 13 ....................................................................... 44
Figure 35: Wetland 14, a Swamp / Fen Complex near km 2 Clowhom Main FSR ........................................... 45
Figure 36: Location, Mapping and Classification of Wetland 14 ....................................................................... 46
Figure 37: Location of Amphibian Detections in Clowhom Watershed, Year 1 (2013-2014) ............................ 47
Figure 38: Western Toad Egg String and Tadpoles in Clowhom Watershed ................................................... 48
Figure 39: Western Toad Detections in Clowhom Watershed, Year 1 (2013-2014) ......................................... 49
Figure 40: Red-legged Frog Egg Mass in Clowhom Watershed, March 2014 .................................................. 50
Figure 41: Wetland 6 Red-legged Frog Breeding Location ............................................................................... 51
Figure 42: Wetland 9 Red-legged Frog Breeding Location ............................................................................... 51
Figure 43: Red-legged Frog Detections in Clowhom Watershed, Year 1 (2013-2014) .................................... 52
Figure 44: Pacific Chorus Frog Adults, Egg Masses and Tadpoles in Clowhom Watershed ........................... 53
Figure 45: Pacific Chorus Frog Observations in Clowhom Watershed, Year 1 (2013-2014)............................ 54
Figure 46: Salamander and Newt Observations in Clowhom Watershed, Year 1 (2013-2014)........................ 56
Figure 47: Owl Detections in Clowhom Watershed, Year 1 (2013-2014) ......................................................... 58
Clowhom Watershed Species at Risk and Habitat Surveys
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Figure 48: The Clowhom Watershed Includes a Diversity of Wetland and Riparian Subclasses ..................... 62
Figure 49: Clowhom Watershed is Home to Seven Species of Amphibians .................................................... 66
Figure 50: Western Painted Turtles Were Not Detected in Clowhom Reservoir .............................................. 67
Figure 51: Western Screech-Owl in Clowhom Watershed, March 2014 ........................................................... 68
Figure 52: Other Species at Risk Detected in Clowhom Watershed Year 1 (2013-2014) ................................ 69
Figure 53: Water Level Fluctuations in Wetland 9............................................................................................. 72
Figure 54: The Large Wetland Complex at the end of the Reservoir is Essential to Wildlife ............................ 73
Figure 55: Proximity of Clowhom Main FSR to Western Toad Breeding Site at Wetland 7.............................. 74
Figure 56: The Mature Riparian Forest Adjacent to Wetland 6 is Very Valuable to Wildlife ............................. 75
Figure 57: Screech Owls will use Man-made Nest Boxes................................................................................. 76
Figure 58: Acknowledgement of FWCP on Amphibian and Owl Interpretive Signs .......................................... 82
Figure 59: Acknowledgement of FWCP on Sunshine Coast Wildlife Project Brochure .................................... 83
Figure 60: Acknowledgement of FWCP in Facebook article about Clowhom Project ...................................... 83
Figure 61: Acknowledgement of FWCP on SCWP Web Site Home Page........................................................ 84
Figure 62: Acknowledgement of FWCP on SCWP Web Site Sponsors’ Page ................................................. 84
Figure 63: Acknowledgement of FWCP in Sunshine Coast Wildlife Project Winter Newsletter ....................... 85
Figure 64: Article in the Salal (Sunshine Coast Botanical Garden Newsletter) ................................................ 85
Figure 65: Article in Marsh Wrenderings (Sunshine Coast Natural History Society Newsletter) ...................... 86
LIST OF TABLES
Table 1: Summary of Amphibian Survey Effort, Clowhom Watershed, Year 1 (2013-2014) ........................ 13
Table 2: Public Outreach and Engagement Activities, Year 1 (2013-2014) .................................................. 16
Table 3: Summary of Mapped Wetlands in the Clowhom Watershed, Year 1 (2013-2014) ......................... 21
Table 4: Western Toad Detections in Clowhom Watershed, Year 1 (2013-2014) ........................................ 48
Table 5: Red-Legged Frog Detections in Clowhom Watershed, Year 1 (2013-2014) .................................. 50
Table 6: Pacific Chorus Frog Detections in Clowhom Watershed, Year 1 (2013-2014) ............................... 53
Table 7: Salamander and Newt Detections in Clowhom Watershed, Year 1 (2013-2014) ........................... 55
Table 8: Summary of Owl Detections in Clowhom Watershed, Year 1 (2013-2014) .................................... 57
Table 9: Species at Risk and Other Wildlife Species Detected in Clowhom, Year 1 (2013-2014) ............... 59
Table 10: Site-Specific Management Recommendations for Clowhom Watershed Wetlands ..................... 77
Clowhom Watershed Species at Risk and Habitat Surveys
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1.0 INTRODUCTION
Wetlands and riparian areas are essential to wildlife. In North America, 80% of breeding birds and 50%
of species-at-risk rely on wetlands for some portion of their lifecycle (Tori et al. 2002). More than 30%
British Columbia’s species-at-risk are wetland-dependent (Austen et al. 2008). Wetland and riparian
habitats are also among those most affected by dam construction and hydro operations.
2
The 382 km Clowhom Watershed is located at the head of Salmon Inlet, 32 km northeast of Sechelt on
the Sunshine Coast. The installation of BC Hydro’s Clowhom Dam in the 1950s flooded two existing
lakes and 315 hectares of land to create Clowhom Lake Reservoir (800 hectares at full pool) (FWCP
2011). Footprint issues in the watershed include loss of 41 ha of riparian habitat, 6 km of mainstem, 3 km
of lower tributary channels, and flooding of 430 ha of existing lake, including 17 km of shoreline (FWCP
2011). Other industrial activity in the watershed include logging (Interfor) and two IPP run-of-the-river
projects (Veresen Incorporated’s Clowhom Power operations on Clowhom River, and Regional Power’s
Bear Hydro operations on Bear Creek).
Prior to this study, wetland and riparian habitats and their associated wildlife species at risk had received
very little attention the Clowhom watershed. Clowhom was not included in the Sunshine Coast Sensitive
Ecosystem Inventory (SEI) mapping (Environment Canada 2005). The limited FWCP investment in the
Clowhom basin was focused on fish, rather than wildlife (FWCP 2011). The shíshálh (Sechelt) Nation
and BC Hydro carry out regular seasonal wildlife surveys in the large wetland complex at the end of the
reservoir as part of a 20-year monitoring program (Bates 2007, 2008; Bates et al. 2009, 2011; Bates &
Ferguson 2010; and Ferguson et al. 2012). However, these surveys do not include specialized live
trapping surveys, call-playback surveys, or nocturnal surveys necessary to assess certain key wetland
and riparian-associated species at risk such as amphibians, owls, bats, and water shrews.
There is an urgent need to map and assess wetland and riparian habitats, survey associated species at
risk, and identify and carry out restoration and enhancement activities to benefit these habitats and
species in the Clowhom watershed. To this end, “riparian and wetland mapping and restoration” and
“amphibian surveys” have been identified as two of the five top priorities for FWCP funding in the
Clowhom Basin, according to the 2011 watershed plan (FWCP 2011). The purpose of this four-year
project is to assess and map wetland and riparian habitats, survey associated species at risk, and identify
and carry out restoration and enhancement activities to benefit these habitats and species in the
Clowhom watershed. During this first year of the project (2013-2014), our focus was on assessing and
mapping wetlands, and conducting surveys focused on the following four high priority wildlife species at
risk: Red-legged Frog, Western Toad, Western Painted Turtle, and Western Screech-Owl.
2.0 GOALS AND OBJECTIVES
The objectives of this project are to:
1.
Identify, assess and map wetlands and riparian ecosystems in the Clowhom watershed to
identify sensitive habitats and prioritize sites of future species at risk inventories.
2.
Undertake comprehensive surveys of species at risk and their critical habitat in the Clowhom
watershed in order to identify new occupied sites for threatened and endangered species,
evaluate threats, and prioritize sites for habitat restoration, enhancement, and conservation.
3.
Work with partners to develop, implement, monitor and adaptively manage multi-species
restoration, management and enhancement plans in order to increase and improve habitat
for wildlife and reduce direct threats to populations of species at risk.
4.
Carry out an active outreach, education and engagement program to increase community
participation in wildlife and habitat stewardship activities, and improve awareness of the BC
Hydro Fish and Wildlife Compensation Program and its program partners.
Clowhom Watershed Species at Risk and Habitat Surveys
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3.0 STUDY AREA
2
This project takes place in the 390 km Clowhom watershed, located at the head of Salmon Inlet, 32 km
northeast of Sechelt on the Lower Sunshine Coast (Figure 1). The watershed falls in Coastal Western
Hemlock biogeoclimatic zone, moist maritime and very wet maritime subzones (CWH mm and CWH vm).
Elevations in the watershed range from 30 to 2400 m and vegetation ranges from dense forest to alpine.
This project year (Year 1: 2013-2014), field survey activities focused on wetland and riparian areas along
Clowhom Lake, Clowhom River and Bear Creek. We identified, assessed and mapped 14 wetlands
including a large 33-hectare wetland complex at the north end of Clowhom Reservoir, along with other
smaller wetlands throughout the basin. Amphibian surveys took place in the 14 wetlands and along roads
by the reservoir and Clowhom River. Turtle surveys occurred around the entire reservoir shoreline and in
the larger wetlands. Owl surveys were carried out along 38.5 kilometers of transects in riparian areas
along Clowhom Lake, Clowhom River and Bear Creek (Figure 2).
Figure 1: Location of Clowhom Watershed, Sunshine Coast, BC
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Figure 2: Locations of Survey Activities in the Clowhom Watershed, Year 1 (2013-2014)
(WSOW = Western Screech Owl)
Clowhom Watershed Species at Risk and Habitat Surveys
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4.0 METHODS
4.1 Wetland Mapping and Assessment
We identified, classified, delineated and mapped wetlands in the Clowhom watershed following Sensitive
Ecosystem Inventory (SEI) methods (Environment Canada 2005) with some additions based upon other
standardized survey protocols (BC Ministry of Forests & Range 2010; Green & Klinka 1994; MacKenzie
and Moran 2004).
Wetland features were digitized using ArcGIS 10.1 and photo interpretation of the 2004 Pan 321
enhanced orthophotography layer for BCGS Map sheet 92G, located on the BC Integrated Land
Management Bureau’s GeoBC web map server. This imagery has a resolution of 15 m. Wetlands were
also digitized using Google Earth imagery (2009), which was then converted into an ArcGIS shapefile.
Areas in hectares were then calculated for each wetland. Each wetland was also assessed on the
ground. Ground truthing involved taking photos, sketching and taking detailed notes which were then
used when delineating polygons in ArcMap.
During comprehensive wetland assessments, data collected included measures of wetland physical
characteristics, hydrology, soil, and vegetation (Appendix I). In addition, we evaluated seven subjective
measures of wetland health (wetland health and vigor, site degradation, function, aesthetics, invasive
species, wildlife sign, and probability of future impact), each given a numeric ranking between 1 and 5
(Appendix II).
During this project year (Year 1: 2013-2014), we identified, mapped and assessed 14 wetland sites,
including the large wetland complex at the end of Clowhom Reservoir, along with other smaller wetlands
situated in the Clowhom River and Bear Creek valleys. Nine sites (Wetlands 3-10 and 14) received
comprehensive ground assessment, including evaluation of physical characteristics, soil, hydrology,
vegetation, and amphibian surveys. Five sites (Wetlands 1-2 and 11-13) were assessed using
orthophotography interpretation plus visual inspection and amphibian surveys; these five will receive
more comprehensive ground assessment in Year 2 of the project (2014-2015).
Figure 3: Assessing Wetlands in the Clowhom Watershed
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4.2 Amphibian Surveys
To assess the distribution and abundance of two amphibian species at risk (Red-legged Frogs and
Western Toads), and to evaluate overall amphibian diversity in the Clowhom Watershed, we surveyed
amphibians using a combination of methods following Resource Information Standards Committee
standards (1998) and methods outlined in Olson et al. (1997).
Egg Mass and Perimeter Surveys
Egg mass and perimeter surveys took place in June 2013, September 2013, and March 2014. Water
bodies were surveyed by systematically searching the edges of water bodies for juveniles, larvae,
tadpoles, and egg masses (Figure 4). The number of egg masses per site can be considered to be
equivalent to the number of breeding females in the population (i.e., one egg mass per female) (Hallock &
McAllister 2009; Scott & Woodward 1994). Larger water bodies were searched by kayak, while smaller,
shallow water bodies were surveyed by wading and/or observing with binoculars from the shoreline.
Total survey effort equalled 56 person hours along 14.6 km of shoreline (Table 1).
Figure 4: Amphibian Egg Mass Perimeter Survey
Auditory Surveys and Road Transects
Road transect surveys were used to search for adult amphibians simultaneously with conducting audio
surveys which were used to aid in locating additional wetlands. Survey effort totalled 72 person hours of
auditory surveys along with 16 person hours of road transects along 19 km of road (Table 1).
Clowhom Watershed Species at Risk and Habitat Surveys
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Live Trapping
Live trapping was carried out in Wetlands 6, 8 and 9 between June 13 and 16, 2013. Funnel traps
2
(collapsible mesh minnow traps) were placed randomly at a density of 1 trap per 25m of habitat strata.
Traps were set in the evening and checked the following morning (Figure 5). Floats were placed inside
each trap to ensure that any air-breathing animals that may enter the traps were not harmed (e.g.,
hatchling painted turtles, water shrews). Total trapping effort was 84 trap nights (Table 1).
Figure 5: Live Trapping Aquatic Amphibians Using Funnel Traps
Incidental Encounters
While traveling to and from sites, searching for egg masses, and checking traps, the incidental detections
of adult frogs and other amphibians were also documented.
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Table 1: Summary of Amphibian Survey Effort, Clowhom Watershed, Year 1 (2013-2014)
Survey Methods
Dates
Locations
Total Effort
13-16 June 2013
Wetlands 6, 7, 8, 9 and 10
24 person hours, 9.0 km
6-9 Sept 2013
Wetlands 3, 4, 5, and 14
12 person hours, 2.2 km
27-30 Mar 2014
Wetlands 1, 2, 11, 12 and 13 (novel wetland
surveys) and Wetlands 3-10 and 14 (focused
Red-legged Frog egg mass surveys)
20 person hours, 3.4 km
13-16 June 2013
Wetlands 6, 7, 8, 9 and 10 and Clowhom
Mainline km 2 to km 21
40 person hours
6-9 Sept 2013
Wetlands 3 ,4, 5, and 14
12 person hours
27-30 Mar 2014
Wetlands 1, 2, 11, 12 and 13 (novel wetland
surveys) and Wetlands 3-10 and 14 (focused
Red-legged Frog egg mass surveys)
20 person hours
Road Transects
14-15 June 2013
Clowhom Mainline km 2 to km 21
16 person hours, 19 km surveyed
Live Trapping
13-16 June 2013
Wetlands 6, 8, and 9
84 trap nights
Perimeter Surveys
Auditory Surveys
4.3 Turtle Surveys
th
th
Targeted turtle basking surveys were conducted on Clowhom Reservoir over two days (June 15 and 16
2013) in sunny weather from kayaks following Resource Information Standards Committee methods
(RISC 1998). In addition, while conducting amphibian surveys in suitable habitats (large ponds or lakes),
we searched for turtles by viewing basking habitat with binoculars either from a boat or from shore. We
also assessed potential turtle habitat on the lake by evaluating the availability of potentially suitable
basking, overwintering and nesting habitat. Survey effort included 18.2 targeted search hours, with a
further 12 hours of observation during amphibian trapping sessions. A total of 27.3 km of lakeshore and
wetland habitats were surveyed.
Clowhom Watershed Species at Risk and Habitat Surveys
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4.4 Owl Surveys
To identify areas used by threatened Western Screech-Owls, we established 70 owl survey stations,
located every 400-500 m along transects in suitable riparian habitat. Areas of inappropriate or low quality
habitat (cliffs, large cut blocks, or dense coniferous forest) were excluded. Specific station locations also
took into account safe areas to pull off the road to park.
Of the 70 stations established, 45 are located along a 27 km transect of riparian habitat on the Clowhom
Main Forest Service Road, including 16 sites along the reservoir and 29 stations along the Clowhom
River. Six other stations are situated along a 2.5 km transect along the Powder Main, above the east side
of the main wetland complex at the north end of the reservoir. Another 5 stations, along a 2.5 km
transect, are situated on the east side of reservoir at the south end near the dam. Finally, 14 stations
have been established along the Bear Creek Main over 6.5 km heading east away from the reservoir.
We surveyed owls twice this project year (September 2013 and March 2014). In total, 55 survey stations
were visited: 32 stations visited twice during both fall and spring surveys, 8 visited once during the fall
survey, and 15 visited once during the spring survey. Another 15 stations have yet to be surveyed but will
be visited during the 2014-2015 project year.
Owls were surveyed using nocturnal call playback surveys following RISC standards (Hausleitner 2006).
Surveys took place from one half hour before sunset to one half hour after midnight. Upon arriving at a
station one minute of silence was followed by a one minute playback of a male Western Screech-Owl
“bouncing-ball” territorial call followed by three minutes of silence during which the surveyors listened
intently for any response. This process was then repeated, pointing the caller in each of the four cardinal
directions, for a total survey time of 15 minutes per station. Calls were produced with a Foxpro NX4
electronic caller (Figure 6). Upon any response, the call-playback was stopped and observations as to
the species, distance, direction and duration of the response were recorded. Weather, noise and habitat
conditions at each station were also recorded.
In total, 95 call playback surveys were carried out this project year. During the fall survey (September 6-8
2013), 40 call-playback stations were surveyed. During the spring survey (March 28-30 2014), 47 callplayback stations were visited, six of these stations surveyed twice, for a total of 53 surveys.
Figure 6: Conducting Western Screech-Owl Call-Playback Surveys
Clowhom Watershed Species at Risk and Habitat Surveys
14
4.5 Public Outreach and Engagement
Public outreach and engagement are important aspects of this project. We carried out diverse activities
designed to engage community members in conservation of local species at risk, and increase
awareness of the wildlife stewardship efforts of Fish and Wildlife Compensation Program and its program
partners BC Hydro, the Province of B.C. and Fisheries and Oceans Canada, First Nations and the public.
We gave presentations to community and landowner organizations, provided kids programs for school
classes, and hosted outreach tables at community events and venues (Figure 7). In all, we carried out 45
public engagement events this project year, reaching over 2200 community members of all ages (Table
2). In addition, we published media articles, and provided updates in our newsletter, on our website and
Facebook page, and in newsletters of partner groups. We also designed and produced an amphibian
interpretive sign and an owl interpretive sign (Figure 8). Five copies of each of these signs are currently
being printed and will be installed at various locations, including both the Clowhom watershed and other
more populated areas of the Sunshine Coast. Finally, we encouraged local landowners to sign voluntary
wildlife stewardship agreements pledging to maintain wildlife habitat on their property. This project year,
over 200 Sunshine Coast residents signed up as land stewards covering over 200 hectares of land.
We were proud to acknowledge support of the Fish and Wildlife Compensation Program and its program
partners in all of these venues, and proudly displayed the FWCP name and logo on all of our written and
outreach materials.
Figure 7: Public Outreach Tables, Presentations, and School Programs
Clowhom Watershed Species at Risk and Habitat Surveys
15
Table 2: Public Outreach and Engagement Activities, Year 1 (2013-2014)
DATE
LOCATION
ACTIVITY
AUDIENCE
NUMBER
21-Apr-13
Earth Day Festival, Roberts Creek
Outreach table at event
Community members mostly adults
500
18-May-13
Sunshine Coast BioBlitz
Outreach table at event
Community members all ages
100
28-May-13
Roberts Creek Elementary
Kids program - species at risk
Students Grades 4-5
30
13-Aug-13
Katherine Lake Park
Outreach table at event
Community members all ages
40
19-Sep-13
Iris Griffith Nature School
Kids program - species at risk
Students Grades K-1
21
03-Oct-13
SFU Centre For Coastal Studies event
Presentation - species at risk
University researchers and students
100
22-Oct-13
Roberts Creek Elementary
Kids program - bats
Students Grades 5-7
47
01-Nov-13
Sunshine Coast Natural History Soc meeting
Outreach table at event
Members of SCNHS
50
26-Nov-13
SCCP Species at Risk Dialogue Session
Presentation - species at risk
Local government representatives
12
27-Nov-13
Davis Bay Elementary
Kids program - bats
Students Grades K-3
42
29-Nov-13
Sunnycrest Mall, Gibsons
Outreach table at mall
Community members adults
50
30-Nov-13
Sunnycrest Mall, Gibsons
Outreach table at mall
Community members adults
50
02-Dec-13
West Sechelt Elementary
Kids program - owls
Students Grades 4-5
25
02-Dec-13
West Sechelt Elementary
Kids program - owls
Students Grades 4-5
26
06-Dec-13
Sunnycrest Mall, Gibsons
Outreach table at event
Community members adults
30
10-Dec-13
Kinnickinnick Elementary
Kids program - owls
Students Grades 4-5
27
10-Dec-13
Kinnickinnick Elementary
Kids program - owls
Students Grades 2-3
28
15-Dec-13
Iris Griffith Nature Centre event
Outreach table at event
Lagoon Society members
40
17-Dec-13
West Sechelt Elementary
Kids program - owls
Students Grades 6-7
29
04-Jan-14
Trail Bay Mall, Sechelt
Outreach table at mall
Community members adults
40
15-Jan-14
Gibsons Chamber of Commerce meeting
Outreach table at event
Chamber of Commerce Members
20
22-Jan-14
Town Preschool, Gibsons
Kids program - owls
Preschool students
11
22-Jan-14
Town Preschool, Gibsons
Kids program - owls
Preschool students
10
23-Jan-14
Town Preschool, Gibsons
Kids program - owls
Preschool students
10
25-Jan-14
SCCA Festival of Conservation
Outreach table at event
SCCA members
155
01-Feb-14
Windows on the Water Shop
Outreach table at shop
Community members adults
20
08-Feb-14
Trail Bay Mall, Sechelt
Outreach table at mall
Community members adults
45
26
11-Feb-14
Halfmoon Bay Elementary
Kids program - owls
Students Grades 4-5
12-Feb-14
Windows on the Water Shop
Outreach table at shop
Community members all ages
8
13-Feb-14
Kinnickinnick Elementary
Kids program - bats
Students Grades 2-3
28
18-Feb-14
Pender Harbour Wildlife Society meeting
Presentation - owls
PHWS members
15
19-Feb-14
Children's Community Services
Kids program - bats
Special needs highschool students
10
25-Feb-14
Sunshine Coast Biodiversity Summit
Outreach table at event
local government and NGOs
45
27-Feb-14
Gibsons Rotary Club meeting
Outreach table at event
Rotary Club members
30
28-Feb-14
Davis Bay Elementary
Kids program - owls
Students Grades K-3
38
03-Mar-14
Sunshine Coast Conservation Assoc meeting
Presentation - species at risk
SCCA members
20
11-Mar-14
Woodworkers Guild meeting
Presentation - species at risk
Woodworkers Guild members
50
12-Mar-14
Children's Community Services
Kids program - owls
Special needs highschool students
10
15-Mar-14
Seedy Saturday Event, Roberts Creek
Presentation and outreach table
Community members all ages
350
22-Mar-14
Sunshine Coast Botanical Garden
Workshop - bat house building
Community members all ages
19
23-Mar-14
Sunshine Coast Botanical Garden
Workshop - mason bee box building
Community members all ages
12
23-Mar-14
Sunshine Coast Botanical Garden
Workshop - owl nest box building
Community members all ages
7
25-Mar-14
Spider Homeschooling Program
Kids program - owls
Students Grades K-3
14
25-Mar-14
Spider Homeschooling Program
Kids program - owls
Students Grades 4-6
5
25-Mar-14
Spider Homeschooling Program
Kids program - owls
Students Grades 7-9
10
2255
Clowhom Watershed Species at Risk and Habitat Surveys
16
Figure 8: Owl and Amphibian Interpretive Signs
Clowhom Watershed Species at Risk and Habitat Surveys
17
4.6 Owl Habitat Enhancement
To inform community members about owl conservation issues, encourage community participation in
wildlife habitat enhancement efforts, and increase habitat for Screech-Owls where suitable cavity-forming
nest trees are lacking, we worked with community members of all ages to build over 75 nest boxes for
threatened Western Screech-Owls (Figure 9). The nest boxes were built and installed using construction
plans and recommended best practices for nest box installation as provided by reliable sources (e.g.,
Kaufman 2002, Cornell Lab of Ornithology 2013).
Figure 9: Community Members of All Ages Help to Build Owl Nest Boxes
Clowhom Watershed Species at Risk and Habitat Surveys
18
The owl nest boxes were installed at various sites on the Sunshine Coast. Twenty were installed in the
Clowhom watershed near sites of Western Screech-Owl detections (Figure 10). Another 55 were
installed by landowners and community members in parks and on private properties as part of a “Homes
for Owls” community engagement and wildlife stewardship and monitoring program.
Figure 10: Installing Screech-Owl Nest Boxes in the Clowhom Watershed
Clowhom Watershed Species at Risk and Habitat Surveys
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5.0 RESULTS
5.1 Wetlands
We assessed and mapped 14 wetlands in the Clowhom Watershed (Figure 11, Table 3). Eleven of these
were located along the main Clowhom valley bottom, while three were in the Bear Creek valley. The
sections below provide detailed classifications, locations, descriptions, photographs and mapping of each
of the 14 wetlands, along with discussion of wildlife habitat values, threats, and habitat restoration,
enhancement and mitigation opportunities. Appendix III provides plant species lists for surveyed
Clowhom wetlands.
Figure 11: Locations of Mapped Wetlands in the Clowhom Watershed
Clowhom Watershed Species at Risk and Habitat Surveys
20
Table 3: Summary of Mapped Wetlands in the Clowhom Watershed, Year 1 (2013-2014)
UTM
Wetland Subclasses
Datum: NAD 83
Site #
Location
UTM Zone: 10U
Easting
Northing
Subclass Subclass Subclass
1
2
3
Elevation Perimeter
(m)
(m)
Area
(ha)
1
Off Clowhom
Mainline km 24
470635
5520703
10 WN:sp
234
441
0.22
2
Off Clowhom
Mainline km 24
470747
5520554
10 WN:sp
232
225
0.08
3
Off Clowhom
Mainline km 23.5
470993
5520323
10 WN:sp
233
218
0.09
4
Off Clowhom
Mainline km 20
471600
5517949
10 WN: sp
100
411
0.32
5
Off Clowhom
Mainline km 20
471485
5517732
6 WN:ms
95
788
1.26
6
Off Clowhom
Mainline km 18.5
471516
5516185
10 WN:sp
97
1159
0.84
7
Off Clowhom
Mainline km 17
470474
5514951
7 WN:sp
2 WN:fn
1 RI:fm
57
1156
1.94
8
North part of large
wetland complex,
end of the reservoir
469222
5514238
6 WN:fn
3 WN:bg
1 RI:fm
53
2329
8.45
9
Main part of large
wetland complex,
end of the reservoir
469300
5513850
5 WN:ms
3 RI:fl
2 WN:fn
54
3224
24.22
10
Small bay at north
end of Clowom
Reservoir, km 13.5
468522
5512698
7 WN:ms
3 RI:fm
65
1103
2.55
11
Bear Creek Mainline
km 3.5
461334
5514003
5 WN:fn
5 WN:sp
225
460
0.23
12
Bear Creek Mainline
km 3.5
460969
5513977
10 WN:sw
235
481
0.49
13
Bear Creek Mainline
km 6
459354
5515182
5 WN:sp
5 RI:fm
320
1785
7.90
14
Off Clowhom
Mainline km 2
460796
5506688
5 WN:fn
5 WN:sp
55
812
0.89
4 WN:sp
Wetland Classes: Marsh (WN: ms); Swamp (WN: sp); Fen (WN: fn); Shallow water (WN: sw);
Riparian Classes: High bench floodplain (RI: fh); Medium bench floodplain (RI: fm); Low bench floodplain (RI: fl)
Clowhom Watershed Species at Risk and Habitat Surveys
21
Clowhom Wetlands 1, 2 and 3
Location, Classification and Description: Wetlands 1, 2 and 3 are small (0.45 ha combined) roadside
swamps located at 23 km up the Clowhom Main Forest Service Road between the toe of the western
slopes of Mt. Ossa and the Clowhom River main stem (Figures 12-14). These wetlands are fed by surface
water coming off the steep slopes, and are at least partially ephemeral. During visits in summer 2013 their
extent was limited to deeper sections of roadside ditches. There is a transmission line right of way on the
2
western side of the Clowhom Main FSR which encompasses all of these wetlands except for two 500 m
shallow ponds on the east side of the road. During high water periods, such as those observed in March
2014, water flows along shallow depressions beside the road. It appears that the original hemlock/cedar
forest of this site is now entirely limited to the northeast side of the road. The transmission right of way is
dominated by shrubby species such as Willow (Salix spp.) and Douglas Spirea (Spiraea douglasii), along
with weedy graminoid species such as Soft Rush (Juncus effusius) and Canada Bluejoint (Calamagrostis
canadensis). Soils are sand and gravel with a thin organic veneer in wet depressions.
Wildlife Habitat Value: These wetlands appear to provide suitable potential breeding habitat for many
amphibian species, including Pacific Chorus Frogs, Long-toed Salamanders, Roughskin Newts, Redlegged Frogs and Northwestern Salamanders. If enough water is retained in deeper pools through the
summer months, these pools would also provide suitable breeding habitat for Western Toads. Thus far,
no amphibian activity has been detected at this site, but further surveys will be carried out in Year 2
(2014-2015). Other wildlife observed in Wetlands 1, 2 and 3 included Northern Pygmy-Owls, as well as
abundant Roosevelt Elk sign.
Threats / Management Issues: The main water source for these wetlands is the series of ditches
running along the roadside, which direct runoff into the various pools and channels, before eventually
running into the Clowhom River mainstem. The flow in these ditches is extremely variable, from fast
flowing streams to dry depending on conditions. The several deeper pools that store water along its
course through these wetlands appear to be fairly stable, holding permanent water through dry periods.
Because the hydrology of these sites is very much regulated by culverts and ditches, any changes to the
current drainage system must ensure that adequate water supply still reaches these wetlands, and that
they are not drained, so they continue to function as habitat for amphibians, fish and other wildlife.
If amphibians are breeding in these wetlands, the proximity to the road could pose a problem for
migrating frogs, toads or salamanders. However, the relatively light traffic on the road should be easily
managed. Clowhom Power staff members are the only ones using this section of road at the moment
and could mitigate any effects by exercising caution when driving past this area.
Predation on amphibians could also be elevated in these sites due to lack of cover. Increasing riparian
vegetation and coarse woody debris, managing draining systems to maintain water levels, and mitigating
any road impacts would all be useful restoration activities at this site.
Clowhom Watershed Species at Risk and Habitat Surveys
22
Figure 12: Wetland 1, One of Three Small Swamps Near km 23 Clowhom Main FSR
Figure 13: Wetland 3, One of Three Small Swamps Near km 23 Clowhom Main FSR
Clowhom Watershed Species at Risk and Habitat Surveys
23
Figure 14: Location, Classification and Mapping of Wetlands 1, 2 and 3
Wetland Class: Swamp (WN: sp)
Clowhom Watershed Species at Risk and Habitat Surveys
24
Clowhom Wetland 4
Location, Classification and Description: Wetland 4 is a 0.3 ha beaver swamp next to the Clowhom
Main FSR at approximately km 20. It is fed by a small creek from the western slopes of Mt. Tantalus, and
drains into Wetland 5, before reaching the Clowhom River main stem (Figures 15-16). The small beaver
dam is still functioning well, maintaining deep (> 1.5 m) permanent water at the site. No recent beaver
activity was detected and it appears that beavers have not been active at the site for at least two years.
The transmission right of way from the Clowhom Power generating stations runs over approximately half
of the site. In this area the original forest cover has been replaced by shrubby species such as Willow
(Salix) spp., Douglas Spirea (Spiraea douglasii), and Salmonberry (Rubus spectabilis).
Wildlife Habitat Value: With permanent water with a good mix of shallow and deep areas, this site
provides excellent potential breeding habitat for all six species of pond-breeding amphibians observed in
the watershed. Pacific Chorus Frog males were heard calling at the site, but no egg masses or tadpoles
were found. Further amphibian surveys will be carried out in Year 2 (2014-2015). Wetland 4 is also
frequented by Roosevelt Elk (lots of fresh sign). A Western Screech-Owl was detected from a call
playback station 400 m away in both September 2013 and again in March 2014, and this open wetland
area provides good foraging habitat for the species.
Human Impact / Management Issues: The proximity to the Clowhom Main Forest Service Road could
be a problem for migrating amphibians, however the relatively light traffic on the road should be easily
managed. Clowhom Power staff members are the only ones using this section of road at the moment
and could mitigate any effects by exercising caution when driving past this area. If beavers remain
absent from the site for an extended time, the dam will eventually fail and water levels will drop.
However, this will likely occur gradually, and does not pose any immediate threat to breeding amphibians.
Management activities should focus on mitigating the impacts of the road and transmission right of way
through riparian planting and informing Clowhom Power employees about the sensitivity of the area.
Figure 15: Wetland 4, a Small Beaver Swamp Near km 20 Clowhom Main FSR
Clowhom Watershed Species at Risk and Habitat Surveys
25
Figure 16: Location, Classification and Mapping of Wetlands 4 and 5
Wetland Classes: Swamp (WN: sp) and Marsh (WN: ms)
Clowhom Watershed Species at Risk and Habitat Surveys
26
Clowhom Wetland 5
Location, Classification and Description: Wetland 5 is a 1.3 hectare swamp/marsh complex between
the Clowhom River main stem and the Clowhom Main FSR (Figures 16 and 17). Two streams feed the
wetland, one running through Wetland 4 before draining out into the Clowhom River. The wetland was
originally flooded by a 100 metre long beaver dam which is now failing since there are no longer beavers
active at the site. Approximately half of the area of the former beaver swamp has reverted to marsh
habitat with several channels through the habitat. Higher elevation areas that dried out quickly after the
beaver dam started to fail are now converting back into forest and are dominated by a stand of young
alders. The marsh area is free of woody species, and is covered in graminoid vegetation, particularly
Wool-grass (Scirpus cyperinus).
Wildlife Habitat Value: Wetland 5 appears to provide excellent breeding habitat for all six pond breeding
amphibians found in the valley. Thus far, Pacific Chorus Frogs are the only amphibian species detected;
several adult frogs were observed, and egg masses confirm breeding at the site. Further amphibian
surveys will be carried out in Year 2. The surrounding forest was logged in 1974, but is a healthy,
maturing forest that provides adequate terrestrial habitat for amphibians. A Western Screech-Owl was
detected at a call playback station 200 m from Wetland 5 in both 2013 and 2014, and this open riparian
area offers excellent foraging habitat for this threatened species. Other wildlife detected include a pair of
Canada Geese, as well as other waterfowl, Sooty Grouse, and Roosevelt Elk and Grey Wolf sign.
Human Impact / Management Issues: No restoration activities are necessary at the site. Natural
succession after beaver activity provides excellent habitat for many species, which is also the case if
beavers occupy the site again.
Figure 17: Wetland 5, a Swamp/Marsh Complex between Clowhom River & Clowhom Main FSR
Clowhom Watershed Species at Risk and Habitat Surveys
27
Clowhom Wetland 6
Location, Classification and Description: Wetland 6 is a small swamp fed by several small streams
and seepages, and is aquatically connected to the Clowhom River main stem (Figures 18 and 19). The
low inundated areas are dominated by sedges (Carex spp), Skunk Cabbage (Lysichiton americanus) and
Stink Currant (Ribes bracteosum). The forest surrounding the swamp is low to high bench riparian flood
plain dominated by Sitka Spruce, Red Alder, Western Red Cedar, and Big Leaf Maple.
Wildlife Habitat: Red-legged Frog egg masses were observed in Wetland 6 in late March 2014, in small
pools next to the main channel, and an Ensatina Salamander was discovered in the woody debris in the
riparian habitat next to the wetland. The partially closed canopy and relatively cool water make Wetland 6
an unlikely spot for breeding Western Toads. The site appears to provide excellent potential habitat for
Pacific Water Shrew, and important off channel habitat for fish. The mature Sitka Spruce forest on the
floodplain between this wetland and the mainstem of the Clowhom River offers superb habitat for many
species including Western Screech-Owls, which were detected nearby in 2014.
Human Impact / Management Issues: The wetland is immediately adjacent to the Clowhom Main
Forest Service Road. Road mortality may be a threat for migrating amphibians, but this should be easily
mitigated since the only traffic along this stretch of road are the Clowhom Power operators, who can be
made aware of the location and timing of likely migrations so they can avoid running over any individuals.
This particular place on the road looks stable and sediment inputs from slide events are unlikely. The
west side of the wetland is undisturbed mature riparian forest with very large Sitka Spruce and provides
excellent habitat for many species of wildlife including Western Screech-Owls. Efforts should be made to
ensure there is no future alteration of this habitat through harvest or any other industrial activities. No
restoration activities are needed at this site at present.
Figure 18: Wetland 6, a Small Swamp near km 18.5 Clowhom Main FSR
Clowhom Watershed Species at Risk and Habitat Surveys
28
Figure 19: Location, Mapping and Classification of Wetland 6
Wetland / Riparian Classes: Swamp (WN: sp)
Clowhom Watershed Species at Risk and Habitat Surveys
29
Clowhom Wetland 7
Location, Classification and Description: Wetland 7 is a very heterogeneous 2 hectare wetland
complex, sandwiched between the toe of a mountain and the Clowhom Main road, with the water flowing
under the road and eventually into the Clowhom River (Figure 22). Transmission lines are running
through the wetland, including two poles. Wetland 7 receives is moisture from several small streams and
seepages flowing off of the adjacent slope. In general the area is a former beaver swamp, which is now
slowly transforming to a fen community dominated by dominated by Carex species, brown mosses, small
trees (Sitka Spruce, Red Alder) and shrubs (Figure 20). In some areas there are deep pockets of mesic
organic soils, while in others, sandy textured mineral soils prevail. Water flows though the wetland and
gathers in deeper (0.2-1.0 m) sandy bottomed pools near the road; groundwater flows under the road,
and gathers in pools and channels (Figure 21), eventually draining into the Clowhom River.
Wildlife Habitat Value: We observed several thousand Western Toad tadpoles in the pools adjacent to
the road in June 2013. However, surveys the channels and pools in the upstream areas of the wetland,
revealed very few tadpoles outside of this main congregation. Tadpoles were also observed on the
opposite (west) side of the road in shallow pools. Water levels appear to be stable in the pools where
tadpoles were observed, and should provide adequate habitat to allow the toads to reach metamorphosis.
Wetland 7 does not appear to be high quality Red-legged Frog habitat, and none were observed in either
2013 or 2014. The area receives high use from Roosevelt Elk and Columbia Black-tailed Deer. One
North American Water Vole was also observed. A Western Screech-Owl was observed nearby in 2014
and this area provides important foraging habitat for this species at risk.
Human Impact / Management Issues: There are several features of Wetland 7 that may be problematic
for wildlife. Because transmission lines run over the wetland, it may be subject to periodic brushing and
vegetation removal, which can be very detrimental depending on how it is undertaken. If careful hand
removal is practiced, however, the clearing may be beneficial for Western Toads, as it will maintain a
sunny exposure and warm temperatures for tadpole development.
Because the wetland is adjacent to the main road used to access the two hydro projects upstream,
migrating adult and juvenile toads may be threatened by road mortality. If road use increases (if logging
activity were to dramatically increase traffic, for example), road mortality could likely be mitigated
effectively by communicating with those who use the road so that they are aware of the location and
timing of toad movements, and can simply slow down for the few hundred metres of adjacent road and
avoid driving over toads.
The road and transmission lines have also brought some introduced and native weedy species to the
area, but these weeds seem to be confined to the gravelly areas at the roadside and around the
transmission poles. Further monitoring of the spread of these species should be undertaken to determine
if removal is necessary.
Clowhom Watershed Species at Risk and Habitat Surveys
30
Figure 20: Fen / Swamp Area of Wetland 7 on East Side of the Road
Figure 21: Riparian Flood Plain Area of Wetland 7 on West Side of Road
Clowhom Watershed Species at Risk and Habitat Surveys
31
Figure 22: Location, Mapping and Classification of Wetland 7
Wetland / Riparian Classes: Medium bench floodplain (RI: fm); Fen (WN: fn); Swamp (WN: sp)
Clowhom Watershed Species at Risk and Habitat Surveys
32
Clowhom Wetland 8
Location, Classification and Description: Wetland 8 is part of the large wetland complex situated at the
mouth of the Clowhom River where it enters the Clowhom Reservoir (Figure 25). This particular section
of the wetland does not appear to be inundated by the reservoir at any time. Several small inflow streams
bring water and mineral sediment into the wetland which is a poor fen dominated by numerous Carex
species on deep, mesic, organic soils (Figure 23). On drier and elevated microsites, particularly those
away from the influence of the inflow streams, bog-like conditions prevail with Labrador Tea, Sitka
Spruce, Bog Cranberry and Sphagnum mosses dominating (Figure 24). In other areas, well-humified
pockets of the peaty soil have sunk and are dominated by Buckbean, Skunk Cabbage and Yellow Pond
2
Lily. The streams feed a small (800 m ) pond of shallow (~40 cm) water.
Wildlife Habitat Value: This wetland is one of the most important locations for wildlife in the Clowhom
watershed. The site supports a high diversity and abundance of invertebrates (water striders, arachnids,
numerous beetles, dragonflies and damselflies, butterflies and moths, etc.) and provides excellent habitat
for songbirds, amphibians, and mammals. Numerous species of breeding birds (Common Yellowthroat,
Song Sparrow, Black-throated Grey Warbler, and many others) were detected and lots of very fresh sign
of Roosevelt Elk, Columbia Black-tailed Deer, and Black Bear were observed. A Grizzly Bear was
reported in the area in 2013 and this wetland offers excellent spring and summer foraging habitat for this
species. Three fish species were observed in Wetland 8 (Threespine Stickleback, Western Brook
Lamprey, Sculpin species), along with five herptile species (Rough-skinned Newt, Northwestern Garter
Snake, Long-toed Salamander, Northwestern Salamander, and Pacific Chorus Frog, the latter two of
which were confirmed breeding). The site may be a suitable location for Red-legged Frog breeding and
upland habitat, but none were observed in either 2013 or 2014 surveys. The wetland does not appear to
offer high quality breeding habitat for Western Toads, but it is possible that they will use the area.
Human Impact / Management Issues: Human impacts to this site are limited to areas immediately
adjacent to the Clowhom Main Forest Service Road. There are some invasive weeds (Cirsium arvense,
Leucanthemum vulgare) that are confined to the perimeter of the wetland along the road. The thick
sedge and rush that dominate the wetland will likely prevent invasive plants from becoming established
within the wetland itself.
The area receives water from a few small streams that cross the road, as well as rain, and so is not
directly influenced by the reservoir level as is the case for Wetland 9. So long as the culverts are
maintained (which is necessary for road maintenance) there should be no problems with hydrology.
It appears that hunters occasionally use the area, but aside from an old platform to keep hunters above
the wet ground, and a small amount of garbage at the roadside, we observed no negative impacts
associated with that activity. The wetland is used heavily by ungulates and provides excellent spring and
fall habitat for Grizzly Bear. If human use of the site increases above current levels, these species may
suffer due to disturbance. However, the remote nature of the site makes this unlikely.
Clowhom Watershed Species at Risk and Habitat Surveys
33
Figure 23: Fen Area of Wetland 8
Figure 24: Bog Area of Wetland 8
Clowhom Watershed Species at Risk and Habitat Surveys
34
Figure 25: Location, Mapping and Classification of Wetlands 8 and 9
Wetland Classes: Bog (WN: bg); Fen (WN: fn); Marsh (WN: ms); Shallow water (WN: sw)
Riparian Classes: High bench floodplain (RI: fh); Medium bench floodplain (RI: fm); Low bench floodplain (RI: fl)
Clowhom Watershed Species at Risk and Habitat Surveys
35
Clowhom Wetland 9
Location, Classification and Description: Wetland 9 is the downstream portion of the large wetland
complex at the mouth of the Clowhom River, and includes a diversity of wetland subclasses including
marsh, bog, fen and riparian flood plain (Figures 25 and 26). This section of the wetland has a
dramatically fluctuating water table, subject to frequent inundation and draw down from the reservoir
downstream. While surveying the area in June 2013, the water level dropped close to three feet in as
many days. Raised sites are high and medium bench riparian flood plain dominated by conifers and
deciduous trees. The lower areas are fens dominated by Carex species, fringed with willows.
Wildlife Habitat Value: This section of wetland supports a high abundance and diversity of animals and
plants and is clearly important habitat for Roosevelt Elk, Columbia Black-tailed Deer, and numerous
breeding songbirds. Western Toad tadpoles were observed in 2013, and Red-legged Frog egg masses
in 2014, both at very low densities. Because of the fluctuating water levels it is difficult to assess this area
for its potential as amphibian habitat. The upland habitat is excellent for adults, but breeding may be
problematic as drying pools may not remain long enough for juveniles to develop.
Human Impact / Management Issues: If water levels rise too quickly, inundation with cold lake water
may lower temperatures dramatically, and change the habitat availability. Conversely, if water levels drop
too quickly, pools will likely dry out and tadpoles may become stranded. Because the wetland is directly
connected to the reservoir, large fish may also present an increased predation risk if tadpoles are forced
into deeper water by dropping water levels. A fluctuating water table can be beneficial in many ways
(keeping trees from encroaching on the wetland, providing nutrients and aeration of the soil, etc.).
However, drastic fluctuations are most likely harmful to breeding amphibians. During site visits in 2013
and 2014, water level fluctuations of approximately 10 m were observed. It is not clear at this time how
often or quickly these changes occur.
Figure 26: Marsh Portion of Wetland 9, where Western Toad Tadpoles were Found
Clowhom Watershed Species at Risk and Habitat Surveys
36
Clowhom Wetland 10
Location, Classification and Description: Wetland 10 is a wetland complex including a small sedge
marsh at the edge of Clowhom Reservoir (Figure 28), along with medium bench floodplain upland areas
dominated by willows, Big-leaf Maple, Red Alder and Douglas Fir. This location is used as a boat launch,
and a road leads down to the water’s edge. Soils are sandy and relatively nutrient rich for this area.
2
Fluctuating reservoir levels periodically inundate the area, and a small (~150 m ) pool is left when water
recedes.
Wildlife Habitat Value: In June 2013, we observed a pair of Western Toads in amplexus in the small
pool, and later returned to find a string of eggs (Figure 27). Numerous fish were also observed in the
pool. During visits in March 2014, the pool was completely dry and the level of the reservoir was at least
10 m below the point where inundation would refill the pool (Figure 29).
Human Impacts / Management Issues: Similar to Wetland 9, this site is subject to periods of inundation
and drawdown that may have either detrimental and beneficial impacts depending on how the reservoir is
managed. If the pool dries before tadpoles have a chance to metamorphose, the site may become a
population sink. Rapid or prolonged inundation may bring cold water temperatures unsuitable for
breeding toads as well as exposing tadpoles to predatory fish. An analysis of reservoir levels would help
determine what impacts water level fluctuations are having on breeding amphibians at this site.
Figure 27: Western Toad Egg Strings at Wetland 10
Clowhom Watershed Species at Risk and Habitat Surveys
37
Figure 28: Location, Mapping and Classification of Clowhom Wetland 10
Wetland / Riparian Classes: Marsh (WN: ms); Medium bench floodplain (RI: fm)
Clowhom Watershed Species at Risk and Habitat Surveys
38
Figure 29: Water Level Fluctuations at Wetland 10 (June 2013 above, Sept 2013 below)
Clowhom Watershed Species at Risk and Habitat Surveys
39
Clowhom Wetland 11
Location, Classification and Description: Wetland 11 is a 0.25 ha swamp/fen underneath a
transmission right of way, 4 km up the Bear Main Forest Service Road (Figures 30 and 31). Located at
the toe of the slope between a steep mountain and Bear Creek, inflow comes from sheet flows and two
small ephemeral streams. Further surveys are necessary to determine if the wetland is permanent or
ephemeral. The site was clearcut in 1988, and has not had mature forest cover since that time. Formal
vegetation and soil surveys have not been completed at the site, but initial impressions are that soils are
mainly sandy gravel. Vegetation is dominated by shrubs and small deciduous trees (Salix spp., Alnus
rubra, Rubus ursinus). Wet depressions are dominated by sedge and rush species and large amounts of
Skunk Cabbage. There is some Himalayan Blackberry along the roadside.
Wildlife Habitat Value: No amphibians were detected at the site. However, the shallow pools appear to
provide excellent potential breeding habitat for Pacific Chorus Frogs and Long-toed Salamanders,
provided the pools remain until late spring/early summer. Directly across the Bear Main FSR is a patch of
mature old forest surrounding Bear Creek which provides excellent habitat for many species including
terrestrial amphibians. No other wildlife sign was observed at the site, however we did observe Mountain
Goats on the slopes approximately 1 km away, and employees of Bear Hydro L.P. who operate a
generating station on Bear Creek reported seeing Grizzly Bear in the area in 2013.
Human Impact / Management Issues: Habitat enhancement activities at the site should be concerned
with removing any Himalayan Blackberry before it becomes a problem, as well as mitigating road effects
through riparian plantings. Wildlife road mortality should be easily mitigated as the only traffic is the
power plant operator who visits three times a week.
Figure 30: Wetland 11, a Small Swamp / Fen Complex near km 4 Bear Creek FSR
Clowhom Watershed Species at Risk and Habitat Surveys
40
Figure 31: Location, Mapping and Classification of Wetlands 11 and 12
Wetland Classes: Fen (WN: fn); Swamp (WN: sw); Shallow water (WN: sw);
Clowhom Watershed Species at Risk and Habitat Surveys
41
Clowhom Wetland 12
Location, Classification and Description: Wetland 12 is a series of shallow water ponds constructed by
Bear Hydro Limited Partnership. These ponds were built in 2011/2012 to offset small losses in salmonid
habitat, and have since been colonized by Dolly Varden char (Salvelinus malma) (Dave Bates, pers.
comm.). The ponds are less than 5 meters from the Bear Main Forest Service Road. They had no
riparian vegetation as of surveys in March 2014 (Figures 31 and 32).
Wildlife Habitat Value: These ponds were created specifically for fish and have limited usefulness as
amphibian breeding habitat due to fish predation on amphibian larvae. However, they add to the general
ecological heterogeneity of the area, which will benefit overall biodiversity. No wildlife was seen at the
site other than unidentified salmonid juveniles (presumably Dolly Varden). Mountain Goats were observed
on steep slopes 1 km away, and there were reports of a Grizzly Bear in the area in 2013.
Human Impact / Management Issues: This constructed fish habitat has yet to be planted with riparian
vegetation and there are currently no plans to do so. The site will regenerate naturally, however, planting
riparian vegetation could help increase functional wildlife habitat much sooner. Since the site is at the
roadside, the longer it remains unplanted with native vegetation, the greater the risk that it will become
colonised with invasive weeds. Himalayan Blackberry was seen nearby, and the site could be monitored
to ensure it does not become established at the site. The large woody debris in the pools is mostly
simple unbranched logs, and a few more complex root wads. If desired, adding some additional woody
debris with smaller branches could help increase complexity, and potentially increase habitat for a greater
range of species.
Figure 32: Wetland 12, a Manmade Series of Ponds Constructed by Bear Creek Hydro
Clowhom Watershed Species at Risk and Habitat Surveys
42
Clowhom Wetland 13
Location, Classification and Description: Wetland 13 is an 8 hectare floodplain/swamp complex that
includes the Bear Creek main stem (Figures 33 and 34). After exiting the upper Bear Creek powerhouse,
the creek flows through a flat section of the valley, at which point it spreads out into several off channels,
and disconnected pools which are fed by surface runoff and groundwater from the creek. The wetland is
situated in a mature Coastal Western Hemlock forest, and provides excellent habitat for many species.
The presence of Coastal Cutthroat in the many off channels may limit the success of amphibian breeding
due to predation, but there are several disconnected pools that may be fish-free.
Wildlife Habitat Value: This mature riparian forest provides excellent potential foraging and breeding
habitat for Western Screech-Owls, and this area is a high priority target for future owl surveys. Waterfowl
and several other bird species were observed in the area, as were sign of Roosevelt Elk. A Grizzly Bear
was reported in the area in 2013.
Human Impact / Management Issues: No restoration activities are required at the site at the time,
although impacts from the nearby road, such as siltation, should be monitored.
Figure 33: Wetland 13, a Riparian Flood Plain / Swamp Complex near km 6 Bear Creek FSR
Clowhom Watershed Species at Risk and Habitat Surveys
43
Figure 34: Location, Classification and Mapping of Wetland 13
Wetland / Riparian Classes: Swamp (WN: sw), Medium bench floodplain (RI: fm)
Clowhom Watershed Species at Risk and Habitat Surveys
44
Clowhom Wetland 14
Location, Classification and Description: Wetland 14 is a 0.9 ha swamp/fen complex just off of the
Clowhom Main Forest Service Road at the 2 km mark (Figures 35 and 36). A 2 metre wide slough runs
north along the toe of the slope of the road, and then into an old beaver swamp/fen with two deep (~2 m)
pools. The area is surrounded by three clearcuts from 1979, 1989, and 2005, respectively, with a small
strip (~40 m wide) of mature forest at the south end. Several large trees were felled into the wetland,
presumably during the earlier harvest. The area between the wetland and the road is dominated by
Himalayan Blackberry, Bracken Fern and Red Alder. The slough has a bright orange colour due to Iron
Hydroxide precipitate coming out of anoxic groundwater from the road cut. Although this colour may
seem alarming, it is apparently not especially harmful to fish or amphibians (Ken Ashley, pers. comm.). It
does indicate high levels of disturbance, however, and given the use of the upslope area as a log
sort/parking area, water quality at the site is a concern. The fen/swamp area around the defunct beaver
dams seems to be functioning well despite the heavy disturbance all around. The water level at the site
has lowered since beavers no longer maintain the two dams, but appears to be stable. Vegetation is
dominated by graminoid species such as Wool-Grass and Common Rush. Soils are sandy, with pockets
of organic soils around 30 cm deep in wet depressions.
Wildlife Habitat Value: Several Long-toed Salamander egg masses were observed in the shallow slough
in March 2014. No Elk sign was seen, likely because this area receives the most human use in the
valley. The deep permanent pools appear to provide excellent potential breeding habitat for Northwestern
Salamanders and Red-legged Frogs. The poor condition of the surrounding forest may be limiting to
terrestrial adults amphibians which is perhaps why none of these species have been observed in the
wetland thus far.
Human Impact / Management Issues: Restoration activities should focus on removing invasive plants
from the area, as well as monitoring water quality.
Figure 35: Wetland 14, a Swamp / Fen Complex near km 2 Clowhom Main FSR
Clowhom Watershed Species at Risk and Habitat Surveys
45
Figure 36: Location, Mapping and Classification of Wetland 14
Wetland Classes: Fen (WN: fn); Swamp (WN: sw)
Clowhom Watershed Species at Risk and Habitat Surveys
46
5.2 Amphibians
Seven amphibian species were detected within the Clowhom watershed: Red-legged Frog (Rana aurora),
Western Toad (Anaxyrus boreas), Pacific Chorus Frog (Pseudacris regilla), Northwestern Salamander
(Ambystoma gracile), Long-toed Salamander (Ambystoma macrodactylum), Roughskin Newt (Taricha
granulosa) and Ensatina (Ensatina eschscholtzii). The locations of all amphibian detections are
summarized in Figure 37.
Figure 37: Location of Amphibian Detections in Clowhom Watershed, Year 1 (2013-2014)
Clowhom Watershed Species at Risk and Habitat Surveys
47
Western Toads
Western Toad detections in Year 1 included 11 adults, 1 egg string and thousands of tadpoles (Figure
38). Toads were detected at 13 spots within the watershed; adult toads were spotted within Wetlands 7,
8, 9 and 10 and at various roadside locations (Table 4, Figure 39). Toad breeding activity was confirmed
in June 2013 at Wetlands 7, 9 and 10.
Table 4: Western Toad Detections in Clowhom Watershed, Year 1 (2013-2014)
UTM
Number and Life Stage
Date
Location
Datum: NAD 83
Survey Type
UTM Zone: 10U
5 tadpoles
14-Jun-13
Wetland 9
469444
5513995
Incidental
1 tadpole
14-Jun-13
Wetland 9
469186
5513801
Trapping
2 tadpoles
14-Jun-13
Wetland 9
469400
5513876
Trapping
2000+ tadpoles
14-Jun-13
Wetland 7
470475
5514959
Perimeter survey
1 adult
14-Jun-13
Wetland 7
470475
5514959
Perimeter survey
1 adult
14-Jun-13
Road near Wetland 7
470205
5514849
Road transect
1 adult
14-Jun-13
Road Km 14.5
468828
5513982
Road transect
1 adult
14-Jun-13
Road Km 16
469757
5514921
Road transect
2 adults in amplexus
15-Jun-13
Wetland 10
468522
5512698
Incidental
1 egg string
16-Jun-13
Wetland 10
468522
5512698
Incidental
1 adult
16-Jun-13
Wetland 8
470499
5514980
Incidental
1 adult
06-Sep-13
Road near Wetland 7
470428
5514912
Incidental
1 adult
06-Sep-13
Road Km 15.5
469328
5514671
Incidental
1 adult
06-Sep-13
Road Km 19
471579
5516544
Incidental
1 adult
06-Sep-13
Road Km 8.5
468120
5512657
Incidental
Figure 38: Western Toad Egg String and Tadpoles in Clowhom Watershed
Clowhom Watershed Species at Risk and Habitat Surveys
48
Figure 39: Western Toad Detections in Clowhom Watershed, Year 1 (2013-2014)
Clowhom Watershed Species at Risk and Habitat Surveys
49
Red-legged Frogs
Red-legged Frog detections consisted of 47 egg masses found in Wetlands 6 and 9 during perimeter
surveys in March 2014 (Table 5, Figures 40-43). In Wetland 6, the breeding was in small pools next to
the main channel (Figure 41). In Wetland 9, the egg masses were discovered in a small rain-fed pond
(Figure 42). Egg masses were generally small, approximately half the size regularly observed in other
areas of the Sunshine Coast. No other Red-legged Frog adult, juveniles, or tadpoles were found during
any of the other amphibian survey activities in the Clowhom watershed.
Table 5: Red-Legged Frog Detections in Clowhom Watershed, Year 1 (2013-2014)
UTM
Number and Life Stage
Date
Location
Datum: NAD 83
Survey Type
UTM Zone: 10U
6 egg masses
27-Mar-14
Wetland 6
471445
5516220
Perimeter survey
20 egg masses
27-Mar-14
Wetland 6
471436
5516228
Perimeter survey
6 egg masses
28-Mar-14
Wetland 9
469407
5513933
Perimeter survey
15 egg masses
28-Mar-14
Wetland 9
469430
5513932
Perimeter survey
Figure 40: Red-legged Frog Egg Mass in Clowhom Watershed, March 2014
Clowhom Watershed Species at Risk and Habitat Surveys
50
Figure 41: Wetland 6 Red-legged Frog Breeding Location
Figure 42: Wetland 9 Red-legged Frog Breeding Location
Clowhom Watershed Species at Risk and Habitat Surveys
51
Figure 43: Red-legged Frog Detections in Clowhom Watershed, Year 1 (2013-2014)
Clowhom Watershed Species at Risk and Habitat Surveys
52
Pacific Chorus Frogs
Pacific Chorus Frog observations included 38 egg masses and hundreds of tadpoles detected in
perimeter surveys, along with hundreds of adults detected during auditory surveys (Table 6, Figure 44).
Egg masses and tadpoles were observed in both June 2013 and March 2014. Breeding was confirmed in
Wetlands 4, 5 and 8, along with a roadside location at kilometre 8 (Figure 45).
Table 6: Pacific Chorus Frog Detections in Clowhom Watershed, Year 1 (2013-2014)
UTM
Number and
Life Stage
Date
Location
Datum: NAD 83
Survey Type
UTM Zone: 10U
5 adults
14-Jun-13
Roadside Km 8
467714
5512473
Audio survey
6 egg masses
15-Jun-13
Roadside Km 8
467714
5512473
Perimeter survey
300+ tadpoles
15-Jun-13
Roadside Km 8
467714
5512473
Perimeter survey
1 juvenile
6-Sep-13
Wetland 4
471600
5517949
Perimeter survey
1 juvenile
6-Sep-13
Wetland 5
471485
5517732
Perimeter survey
1 adult
26-Mar-14
Wetland 7
470475
5514959
Audio survey
1 adult
27-Mar-14
Wetland 14
460796
5506688
Audio survey
32 egg masses
27-Mar-14
Wetland 8
469222
5514238
Perimeter survey
2-5 adults
27-Mar-14
Clowhom – north mainline
470976
5520333
Incidental audio
50+ adults
30-Mar-14
Clowhom – central lake
465636
5511204
Incidental audio
50+ adults
28-Mar-14
Clowhom – central lake
464114
5510944
Incidental audio
50+ adults
28-Mar-14
Clowhom – south lake
461036
5506728
Incidental audio
50+ adults
28-Mar-14
Clowhom – south lake
460979
5507240
Incidental audio
50+ adults
28-Mar-14
Clowhom – south lake
461684
5509563
Incidental audio
Figure 44: Pacific Chorus Frog Adults, Egg Masses and Tadpoles in Clowhom Watershed
Clowhom Watershed Species at Risk and Habitat Surveys
53
Figure 45: Pacific Chorus Frog Observations in Clowhom Watershed, Year 1 (2013-2014)
Clowhom Watershed Species at Risk and Habitat Surveys
54
Salamanders and Newts
Salamanders and Newts found in Clowhom watershed included three pond-breeding species,
Northwestern Salamander (Ambystoma gracile), Long-toed Salamander (Ambystoma macrodactylum),
and Roughskin Newt (Taricha granulosa) along with one terrestrial-breeding species Ensatina (Ensatina
eschscholtzii) (Table 7, Figure 46).
In Wetland 8, we detected one adult Roughskin Newt, one adult Long-toed Salamander, and
Northwestern Salamanders in various stages of development (27 egg masses, 7 larvae, and 3 neotenic
adults). In Wetland 14, we detected 12 Long-toed Salamander egg masses. Incidental detections of two
adult Ensatina salamanders were recorded in Wetland 6 in March 2014.
Table 7: Salamander and Newt Detections in Clowhom Watershed, Year 1 (2013-2014)
UTM
Number and Life Stage
Date
Location
Datum: NAD 83
Survey Type
UTM Zone: 10U
Northwestern Salamander
1 larva
13-Jun-13
Wetland 8
469197
5514250
Trapping
1 larva
13-Jun-13
Wetland 8
469193
5514245
Trapping
1 larva
13-Jun-13
Wetland 8
469223
5514219
Trapping
1 neotenic adult
13-Jun-13
Wetland 8
469237
5514238
Trapping
1 larva
14-Jun-13
Wetland 8
469197
5514250
Trapping
2 larvae
14-Jun-13
Wetland 8
469193
5514245
Trapping
1 larva
14-Jun-13
Wetland 8
469206
5514226
Trapping
2 egg masses (hatched)
14-Jun-13
Wetland 8
469223
5514219
Perimeter survey
1 egg mass (hatched)
14-Jun-13
Wetland 8
469243
5514227
Perimeter survey
1 neotenic adult
14-Jun-13
Wetland 8
469243
5514227
Trapping
1 neotenic adult
14-Jun-13
Wetland 8
469237
5514238
Trapping
24 egg masses
28-Mar-14
Wetland 8
469103
5514353
Perimeter survey
12 egg masses
27-Mar-14
Wetland 14
460899
5506689
Incidental
1 adult
28-Mar-14
Wetland 8
469176
5514161
Incidental
14-Jun-13
Wetland 8
469223
5514219
Trapping
27-Mar-14
Wetland 6
471468
5516230
Incidental
Long-toed Salamander
Roughskin Newt
1 adult
Ensatina
2 adults
Clowhom Watershed Species at Risk and Habitat Surveys
55
Figure 46: Salamander and Newt Observations in Clowhom Watershed, Year 1 (2013-2014)
Clowhom Watershed Species at Risk and Habitat Surveys
56
5.3 Turtles
Despite exhaustive surveys, no turtles were observed during the targeted basking surveys or at any other
time within the watershed.
5.4 Owls
Over the course of our Western Screech-Owl call-playback surveys, we had eight responses by Western
Screech-Owls (Megascops kennicottii kennicottii). Two male Screech-Owls responded to the callplaybacks during the September 2013 surveys, while six male Screech-Owls responded to the calls
during the March 2014 surveys. One survey station (003) was a site of Screech-Owl detections during
both the fall 2013 survey and the spring 2014 survey. During the spring 2014 survey, one station (019)
had two owls responding several hundred meters from each other.
Besides the Screech-Owls, Barred Owls (Strix varia) also responded to call-playbacks at three stations in
September 2013; however, two of those responses may have been from the same individual. In addition,
two Northern Pygmy-Owls (Glaucidium gnoma) were detected incidentally during birding observations in
March 2014.
Survey locations and owl detections are summarized in Table 8 and Figure 47 below.
Table 8: Summary of Owl Detections in Clowhom Watershed, Year 1 (2013-2014)
UTM
Owls Species
Detected
Date
Time
Owl
Survey
Station
Datum: NAD 83
Location
UTM Zone: 10U
Easting
Northing
Elevat
ion
(m)
Western Screech-Owl
06-Sep-13
21:22
003
20 km Clowhom main
471630
5517474
103
Western Screech-Owl
07-Sep-13
21:51
018
9 km Clowhom main
465105
5511094
83
Western Screech-Owl
28-Mar-14
22:00
003
20 km Clowhom main
471630
5517473
103
Western Screech-Owl
28-Mar-14
22:32
022
5 km Clowhom main
461792
5510063
70
Western Screech-Owl
29-Mar-14
21:22
012
14.5 Clowhom main
468848
5513806
82
Western Screech-Owl
30-Mar-14
22:40
007
17 km Clowhom main
470659
5515107
70
2 Western ScreechOwls
30-Mar-14
019
8.5 Clowhom main
464618
5511008
86
Barred Owl
06-Sep-13
23:48
009
16 km Clowhom main
469673
5514939
69
Barred Owl
07-Sep-13
23:56
024
4 km Clowhom main
461347
5509164
63
Barred Owl
08-Sep-13
00:13
025
3.5 km Clowhom main
461238
5508671
54
2 Northern Pygmy
Owls
27-Mar-14
14:30
N/A
24 km Clowhom main
470610
5520751
229
21:26
21:27
Clowhom Watershed Species at Risk and Habitat Surveys
57
Figure 47: Owl Detections in Clowhom Watershed, Year 1 (2013-2014)
Clowhom Watershed Species at Risk and Habitat Surveys
58
5.5 Other Wildlife
In addition to the target species (amphibians and owls), we detected numerous other wildlife species in
the Clowhom watershed. This project year, we recorded 66 vertebrate species (48 bird species, 7
amphibians, 6 mammals, 4 fish and 1 reptile), and documented the presence of seven species at risk
(Western Screech-Owl, Red-legged Frog, Western Toad, Sooty Grouse, Roosevelt Elk, Great Blue
Heron, and Peregrine Falcon) (Table 9).
Table 9: Species at Risk and Other Wildlife Species Detected in Clowhom, Year 1 (2013-2014)
Location
Species at Risk
Other Wildlife Species
Wetlands 1-3
Sooty Grouse, Roosevelt
Elk (sign)
Northern Pygmy-Owl, Pacific Wren, Golden-crowned Kinglet,
Unknown salmonid - Coastal Cutthroat?
Wetland 4
Roosevelt Elk (sign),
Western Screech-Owl
(within 400 m)
Pacific Chorus Frog, Black-capped Chickadee, Dark-eyed Junco,
American Beaver (old lodge)
Wetland 5
Sooty Grouse, Roosevelt
Elk (sign), Western
Screech-Owl (within 200
m)
Pacific Chorus Frog, Black-capped Chickadee, Canada Goose,
Bufflehead, Pacific Wren, Golden-crowned Kinglet, American
Robin, Grey Wolf (prints), American Beaver (old dam)
Wetland 6
Red-legged Frog,
Roosevelt Elk
(prints/pellets)
Ensatina Salamander, American Robin (M/F nesting), Varied
Thrush
Wetland 7
Western Toad, Roosevelt
Elk (sign), Western
Screech-Owl (nearby)
Pacific Chorus Frog, Hairy Woodpecker, Northern Flicker,
Hutton's Vireo, Brown Creeper, Pacific Wren, Golden-crowned
Kinglet, American Robin, Varied Thrush, Song Sparrow, Darkeyed Junco, Pine Siskin, Columbian Black-tailed Deer, North
American Water Vole
Western Toad, Redlegged Frog, Sooty
Grouse, Roosevelt Elk
(sign and cow)
Northwestern Salamander, Long-toed Salamander, Roughskin
Newt, Tree Swallow, Common Yellowthroat, Common Raven,
Cedar Waxwing, Swainson's Thrush, Wilson's Warbler,
Townsend's Warbler, Yellow Warbler, American Goldfinch,
Canada Goose, Mallard, Common Merganser, Ruffed Grouse,
Red-tailed Hawk, Belted Kingfisher, Hairy Woodpecker, Northern
Flicker, Steller's Jay, Chestnut-backed Chickadee, Pacific Wren,
Golden-crowned Kinglet, Ruby-crowned Kinglet, American Robin,
Varied Thrush, Spotted Towhee, Song Sparrow, Dark-eyed
Junco, Pine Siskin, Wilson's Snipe, Rufous Hummingbird, Belted
Kingfisher, Steller's Jay, Black-throated Grey Warbler, Redwinged Blackbird, Western Meadowlark, Columbian Black-tailed
Deer, American Black Bear (prints and scat), Terrestrial
Gartersnake, Threespine Stickleback, Western Brook Lamprey,
Sculpin sp.
Wetlands
8 and 9
Clowhom Watershed Species at Risk and Habitat Surveys
59
Wetland 10
Western Toad
Sculpin sp.
Wetland 11
American Dipper, rodent (scat)
Wetland 12
Wetland 13
Roosevelt Elk
Long-toed Salamander, Pacific Chorus Frog, Columbian Blacktailed Deer (sign), American Beaver (old dam)
Wetland 14
Clowhom
Reservoir
Dark-eyed Junco, Song Sparrow, Varied Thrush, Red-breasted
Sapsucker
Western Screech-Owl
Trumpeter Swan, Common Loon, Pied-billed Grebe, Barred Owl
Clowhom Lower
Powerhouse
NAD 83 10U
Easting 471799
Northing 5519489
Great Blue Heron
Upper Clowhom
near owl survey
station 35
Peregrine Falcon
NAD 83 10U
Easting 469754
Northing 5522599
Clowhom Watershed Species at Risk and Habitat Surveys
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6.0 DISCUSSION
6.1 Wetlands
Wetland habitats are very limited in scope and abundance in Clowhom due to the watershed’s generally
steep slopes and narrow valley bottom. There was likely a substantial loss of lowland wetland and
riparian habitats when the lower valley was flooded with the construction of the Clowhom dam.
Of the wetlands identified and mapped thus far, most are relatively small; the majority are less than a
hectare in area. The largest wetlands include the 33 hectare wetland complex at the northern end of the
reservoir at the confluence with the Clowhom River, and an eight hectare area of swamp and riparian
floodplain on Bear Creek. A diversity of wetland and riparian subclasses are represented in the
watershed, including swamp, fen, bog, marsh, shallow water, and low, medium and high bench floodplain
(Figure 48).
The most common type of wetlands in the Clowhom watershed are small swamps. Most of these have
been created by beaver activity, which is essential for the existence of diverse wetland habitats in the
region. Beavers are fairly ephemeral on the landscape, creating large, deep swamps by blocking and
diverting streams, and then disappearing through predation, disease, and dispersal. As beaver dams fail,
their swamps drain, and depending on the hydrological and soil conditions, the swamps slowly transform
into other wetland classes such as marshes (with high nutrient inputs and oxygenated, flowing water) or
fens (with lower nutrient inputs and slower moving, less oxygenated water). Other small swamps have
been created by roads impounding water in shallow pools that eventually drain into the Clowhom River
mainstem through culverts and small stream channels.
The large wetland complex at the end of Clowhom Reservoir is more representative of the type of habitat
that likely existed prior to the construction of the dam. This area incorporates many different wetland
classes, with small inclusions of bog, swamp and shallow water within the dominant fen and marsh
communities. The wetland provides highly productive habitat for a great diversity of wildlife species,
including invertebrates, frogs, toads, salamanders, snakes, small mammals, waterfowl, songbirds,
raptors, ungulates and carnivores. The site includes both an area of stable, natural wetland (Wetland 8),
along with areas where the wetland habitat is greatly influenced by the dramatic, unnatural, and
unpredictable raising and lowering of reservoir water levels (Wetland 9).
While the amount of true wetland habitat is quite limited in the watershed, most of the Clowhom valley
bottom is low, medium and high bench riparian floodplain. The highly unstable slopes deliver large
amounts of sediment to the stream and river channels. The intense forest harvesting in the valley, and
subsequent erosion, has also contributed to the amount of sediment entering the streams and river. This
high sediment load creates wide, braided channels that constantly shift and move across the valley floor.
The sandy, gravelly fluvial deposits are part of the reason that wetlands are so limited in the valley; these
soils are so well drained that, in most areas, water is not retained at the surface.
Typically, the wettest, lowest areas of the floodplain, closest to wetlands or stream channels, are low
bench floodplains, dominated by forbs and grasses. Low bench habitats are restricted to locations where
the stream gradient is very low, where finer sediments accumulate and frequent flooding restricts the
growth of larger woody vegetation. Medium bench areas are slightly higher above the nominal water
table, and are dominated by willows and other shrubs. Medium bench sites are fairly common along the
valley floors, particularly along the Clowhom River mainstem. High bench floodplains are at the highest
end of the elevation gradient relative to the water table. These areas are flooded infrequently, but still
have relatively high water tables. They are dominated by riparian tree species such as cottonwoods
(Populus balsamifera ssp. trichocarpa), Sitka spruce (Picea sitchensis), and red alder (Alnus rubra). High
bench floodplains are common on the valley floor, but most have been altered due to forest harvesting,
road building, and transmission line right of ways. Clowhom’s productive and heterogeneous floodplain
habitats support a great deal of floral and faunal biodiversity within the valley.
Clowhom Watershed Species at Risk and Habitat Surveys
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Marsh
Swamp
Fen
Bog
Riparian Floodplain
Shallow Water
Figure 48: The Clowhom Watershed Includes a Diversity of Wetland and Riparian Subclasses
Clowhom Watershed Species at Risk and Habitat Surveys
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6.2 Amphibians
Amphibians are considered one of nature’s best indicators of biodiversity and overall ecosystem health in
both aquatic and terrestrial ecosystems due to their longevity, small territory size, site fidelity, and
sensitivity to environmental alterations. Amphibians drink and breathe through their permeable skin and
are highly sensitive to pollution and environmental degradation. They are vulnerable to many threats
including habitat loss and modification, invasive species, pollution, fungal and viral pathogens, ozone
layer depletion (increased UV), climate change and road mortality. Globally, amphibians are in decline
with more than 40% of Earth’s amphibian species threatened with extinction (IUCN 2014).
Our surveys indicate that Clowhom watershed is home to at least seven amphibian species, including two
species at risk (Western Toad and Red-legged Frog) (Figure 49).
Red-legged Frog
Red-legged Frogs are blue-listed in BC, federally classified as a species of special concern, and listed as
Identified Wildlife under the BC Forest & Range Practices Act (COSEWIC 2002a, Maxcy 2004).
Important habitat for these frogs includes forested pools, wetlands with shallow water (particularly bogs
and fens), and fringes of lakes. They can breed in a wide-range of aquatic habitat but prefer to attach
their egg masses to woody debris, such as fallen trees, willow or Spirea branches, or to stalks of
emergent vegetation, such as rushes or sedges. Juveniles and adults spend much of their time on land;
up to 90% of feeding and growth occurs terrestrially, typically in cool, moist forested environments. Thus
the species requires intact upland habitat adjacent to breeding sites in order to maintain viable
populations.
Despite intensive amphibian survey effort, we detected very few Red-legged Frogs in the Clowhom
watershed compared with other regions of the Sunshine Coast. The most likely explanation for the
relatively low density of the species began with the initial flooding and loss of lowland wetland
ecosystems that were present prior to dam construction. In addition to this significant loss of prime
habitat, decades of drastic water level fluctuations likely caused mass mortality of egg masses and larvae
and severely limited productivity. Further negative impacts likely came from widespread forest harvesting
which altered the hydrology of wetlands and limited the suitability and availability of terrestrial forested
habitats.
This year we confirmed Red-legged Frog breeding in only two Clowhom wetlands, Wetland 6 and 9. Of
note is the generally small size of egg masses discovered, approximately half the size regularly observed
in other areas of the Sunshine Coast. The reason for this is not fully understood but further study will be
conducted. Size of egg mass is often correlated to body size and age of female frogs and may suggest
that Red-legged Frogs breeding in the watershed are generally young and small individuals.
In Wetland 6, Red-legged Frog eggs were found in shallow forested pools in a largely intact mature
riparian forest patch. As long as this habitat remains unharvested it could sufficiently support a small
population of Red-legged Frogs. Some road impacts may be occurring but could be mitigated by fencing
and potentially planting roadside vegetation to limit runoff and siltation.
In Wetland 9, Red-legged Frog breeding success is most certainly being affected by the frequency and
rate of drawn down in this area. In March 2014, Red-legged Frogs laid eggs in some remaining small
pools. However, success of this breeding event has yet to be determined and will depend on the timing
and degree of water level changes right up until August, at which time most tadpoles should
metamorphose into juvenile frogs. Habitat quality in this wetland complex is high so long as water levels
can be managed to minimize negative impacts and maximize opportunities for successful breeding.
Many other Clowhom locations, including Wetlands 1, 2, 3, 4, 5 and 14, appear to provide excellent
potential breeding habitat for Red-legged Frogs. We will continue amphibian surveys in the 2014/2015
project year to determine if any other occupied sites exist for this species at risk within the watershed.
Clowhom Watershed Species at Risk and Habitat Surveys
63
Western Toad
Western Toads are blue-listed in BC and federally classified as a species of special concern (COSEWIC
2002b). One of the few Canadian amphibians on the IUCN Red List of Threatened Species (category
“Near Threatened”), the Western Toad was once abundant throughout western North America, but has
recently experienced devastating declines, with large populations disappearing mysteriously from many
areas, including parts of BC (IUCN 2014, COSEWIC 2002b). The species is found in diverse ecosystems
from valley bottoms to sub-alpine elevations. Important breeding habitat for Western Toads includes
shallow, warm ponds, lake margins, slow-flowing streams, marshes, bogs and fens. Extensive terrestrial
habitat is required for growth, feeding and overwintering.
Western Toads normally breed in mass, with all members of a local population gathering together at the
same time in the same location, which is often used repeatedly from year to year. After eggs hatch,
tadpoles gather together in dense aggregations or schools. At the end of the summer, juvenile toadlets
disperse from breeding ponds together.
This year, we documented three separate breeding sites for Western Toads (Wetlands 7, 9, and 10).
Adult toads were found at several other locations, suggesting that more breeding sites may exist. Within
the Clowhom watershed, breeding appears to be spread out over several weeks. Over a 4-day period in
June 2013, we observed eggs (Wetland 10), very young tadpoles (Wetland 7), and tadpoles with welldeveloped leg buds (Wetland 9).
Wetland 7 is the most productive Western Toad breeding site discovered thus far in the watershed, with
more than 1000 tadpoles observed. Maintenance of the hydro right of way at this site has promoted high
habitat quality by creating open warm wetland pools. However, the transmission corridor also poses
threats that could impact survivability, such as road mortality and possible chemical treatments of
vegetation. To mitigate any negative impacts on this important breeding site, we recommend
encouraging best practices during transmission line right of way maintenance, and reducing road
mortality risks through signage and, if necessary, fencing and/or a road crossing structure.
Wetlands 9 and 10 offer high quality habitat when water levels are sufficient. However, Western Toad
breeding success is being affected by frequent water level fluctuations at these sites. In Wetland 9,
tadpoles were found in the fringes of the wetland at a time when water levels dropped several feet in a
few days, placing the remaining pools at risk of drying up before the larvae could complete
metamorphosis. In Wetland 10, an egg string was observed being laid in June but the wetted area had
dried up when revisited in August.
During the 2014-2015 project year, we will continue amphibian surveys to search for more occupied sites
and breeding ponds for Western Toads in the Clowhom watershed. We will also monitor breeding
success and water levels at known breeding sites and evaluate movements of juvenile toads to assess
road impacts.
Pacific Chorus Frog
These tiny frogs are only 3-4 cm long, but have huge voices. Pacific Chorus Frogs are the ones you hear
ribbiting outside your window on wet spring nights. They are common in southern BC and outside of
breeding season can use a great variety of habitats. They breed in shallow wetlands and ponds with
abundant plant cover. Often these breeding sites are ephemeral and dry out by the end of summer,
keeping them clear of predatory fish that require permanent water bodies.
We documented Pacific Chorus Frogs calling at diverse sites throughout the Clowhom basin, and
confirmed breeding at four locations (Wetlands 4, 5, 8 and a roadside location at km 8). Timing of
breeding is spread out in the watershed. In June 2013 we observed Chorus Frogs of diverse life stages,
from mating adults in amplexus, to eggs, to tadpoles in varying stages of development.
Clowhom Watershed Species at Risk and Habitat Surveys
64
Northwestern Salamander
The Northwestern Salamander is one of the most common pond-breeding amphibian species in BC. This
relatively large salamander can reach a maximum length of 24 cm. Northwestern Salamanders depend
on both forests and permanent water bodies for their survival. They are most common in mature, cool,
moist forests, where they spend most of their time underneath rocks, logs or other woody debris, or in
underground mammal burrows. Like other aquatic-breeding salamanders, this species lays its eggs in
water bodies, and the young hatch into a gilled larval stage, which transforms into a gill-less adult which
moves to land. However, some adult Northwestern Salamanders retain their juvenile characteristics into
their adult life, keeping their gills and remaining in the breeding pond for several years (“neotenic adults”).
We observed Northwestern Salamander egg masses, larvae, and neotenic adults in the large wetland
complex at the end of Clowhom reservoir (Wetland 8). Suitable potential breeding habitat exists in
several other wetland sites in the watershed and further amphibian surveys in 2014/2015 may uncover
more occupied sites for this species.
Long-toed Salamander
This long, slender salamander is approximately 8 cm long and is named for the extra-long fourth toes on
its hind feet. On land, it lives in a variety of habitats, from forests and woodlands to meadows and
agricultural areas, normally close to the shallow lakes, ponds and bogs where it breeds. This secretive
species spends most of its time underground beneath logs, rocks, or woody debris, or inside rodent
burrows. The Long-toed Salamander is one of the earliest breeding amphibian species in the province.
In some sites these salamanders will migrate across snow to breeding ponds and deposit eggs in water
bodies even before all ice has melted.
In March 2014, we observed 12 Long-toed Salamander egg masses in Clowhom Wetland 8 and one adult
salamander in Wetland 14.
Roughskin Newt
Another pond-breeding amphibian, the Roughskin Newt protects itself from predators using tetrodotoxin
(TTX), a powerful neurotoxin, which is more than 1,000 times more toxic than cyanide. Roughskin Newts
breed in ponds, lakes, wetlands, or slow moving streams, laying their eggs singly on vegetation along
shallow, vegetated shorelines. Outside of breeding season, some adults migrate to surrounding forested
environments where they live in and under rotting logs, while others stay in lakes or ponds throughout the
summer or year round.
In June 2013, we captured one adult Roughskin Newt at Wetland 8, and the species is presumed to
breed in this wetland complex.
Ensatina Salamander
This species (a member of the Plethodontid family, or “Lungless Salamanders”) lives its entire life on land
on the forest floor, normally sheltering under or within rotting logs, bark and other woody debris. It lays
eggs in damp places like inside rotting logs or under rocks. The young go through a gilled stage inside
the egg, and hatch as miniature adults. Like other Plethodontid species, the Ensatina has no lungs and
absorbs oxygen entirely through its skin and the mucous membrane in the mouth and throat.
In March 2014, we recorded incidental encounters of two adult Ensatinas in Wetland 6.
Clowhom Watershed Species at Risk and Habitat Surveys
65
Western Toad
Red-legged Frog
Roughskin Newt
Pacific Chorus Frog
Long-toed Salamander
Northwestern Salamander
Ensatina
Figure 49: Clowhom Watershed is Home to Seven Species of Amphibians
Clowhom Watershed Species at Risk and Habitat Surveys
66
6.3 Turtles
The Western Painted Turtle is BC’s only remaining native freshwater turtle species. The Pacific coast
population is federally endangered and provincially red-listed (COSEWIC 2006). These turtles are
vulnerable to wetland loss and degradation, destruction of nesting habitat, predation, human disturbance,
alien species, and mortality on roads intercepting nesting areas. The Lower Sunshine Coast is home to
home to some of the most important remaining populations of Western Painted Turtles in coastal BC,
including at least 17 occupied sites (WPT Recovery Team 2014). The closest known occupied site to
Clowhom watershed is in the Pender Harbour region, approximately 35 km away.
It is unclear whether Painted Turtles were ever present in Clowhom watershed. The Clowhom Watershed
Plan (FWCP 2011) states that “the turtle population in Clowhom Lake seems to have crashed after the
reservoir level was increase by five feet in 1952”. It is important to determine the authenticity of this
statement, but assuming it is true, it may be beneficial to continue searching for turtles in all water bodies
within the watershed as they could potentially be concealing a small population. Considering that the
event that apparently caused the turtle population to crash was 60 years ago, it is unlikely that there
would be any surviving turtles unless there had been successful reproduction and recruitment.
The creation of the Clowhom Dam flooded two small lakes and surrounding lowland areas (BCRP 2000,
FWCP 2011). The habitat that existed prior to dam creation was likely superior to what remains.
Clowhom reservoir, as it exists today, is cold, steep sided, and has little appropriate habitat for turtles.
There are a few small bays at the northeast end of the lake and in the large wetland complex at the
mouth of the Clowhom River, but these site are dominated by sedges rather than the softer submergent
and floating vegetation typically associated with turtle habitats in other areas of the Sunshine Coast.
These areas are also exposed to frequent high winds which may influence water temperature as well as
the benthic substrate. There appears to be ample potential turtle nesting habitat in the form of sandy
shores. However, the wildly fluctuating water table likely floods these shoreline areas for long periods of
time, making them unsuitable. Basking habitat is not limited, as large amounts of woody debris are
present on the lake. Most of these logs have been pushed by prevailing winds to the more suitable
habitat in the northeast end of the reservoir.
Unless a surviving population is found, habitat restoration for turtles in Clowhom would be unnecessary,
although opportunities exist in several locations.
Figure 50: Western Painted Turtles Were Not Detected in Clowhom Reservoir
Clowhom Watershed Species at Risk and Habitat Surveys
67
6.4 Owls
Our surveys documented the presence of three owl species in Clowhom watershed, including the
federally threatened and provincially blue-listed Western Screech-Owl. While the interior Western
Screech-Owl subspecies (Megascops kennicottii macfarlanei) has been the subject of intensive inventory
effort over the past decade (e.g., Dulisse & Beaucher 2006, Ferguson & Iredale 2007, Hausleitner et al.
2007, Davis and Weir 2008, Hobbs 2013a, b, c), the coastal subspecies (Megascops kennicottii
kennicottii) has received relatively little survey attention. However, there are strong indications that these
owls are declining, both in the south coast area and in the northern part of their range (Kissling & Lewis
2009). Western Screech-Owls appear to have nearly disappeared from the Vancouver Lower Mainland,
Victoria and the Gulf Islands. A rough estimate in the latest COSEWIC Status Report (2012) suggests
that the coastal subspecies has declined by 20 to 30% in Canada over the past 10 to 15 years. On the
Sunshine Coast, Western Screech-Owls were relatively common before until declining sharply in the
1990s (Tony Greenfield, pers. comm.). By 2001, Preston and Campbell failed to detect any Screech-Owls
in 156 survey stations on the Sunshine Coast (COSEWIC 2012). Prior to our recent detections in
Clowhom, there had been only 12 documented sightings of Western Screech-Owls on the Lower
Sunshine Coast in the past 12 years, the most recent of which was in 2011 (T. Greenfield, pers. comm).
This project year, we recorded eight Western Screech-Owl detections in the Clowhom watershed. All
Screech-Owls were found in mixed riparian forest at elevations of 103 meters or lower. This is consistent
with observations from other regions where the subspecies is associated with low elevation, late
successional riparian forest habitat, typically with deciduous elements and large diameter cavity-forming
trees for nesting (COSEWIC 2012). Such habitat is now relatively limited in Clowhom. The flooding of
the lower valley to create the reservoir eliminated 41 hectares of riparian forest (FWCP 2011). Wide scale
forest harvesting caused further losses of riparian and mature forest habitat and removed dead trees and
snags that could serve as potential nesting trees. To aid with the survival of this species at risk, it is
essential to maintain remaining areas of low elevation late successional riparian forest and large diameter
cavity-forming trees within identified Western Screech-Owl territories.
We detected Barred Owls at three spots in the watershed. This species has expanded its range into the
BC south coast over the past 50 years and is now established as a resident breeding species. Barred
Owl depredation has been strongly implicated in the decline of Western Screech-Owls (Cannings and
Angell 2001, Elliot 2006). The presence of Barred Owls may hinder survival of Screech-Owls in Clowhom.
Screech-Owls are non-migratory and pairs will occupy and defend territories year-round. During Year 2
of the project, we will continue surveys to identify territories and search for nest trees. All identified nests
will be monitored throughout the nesting and post-fledgling period to evaluate reproductive success.
Figure 51: Western Screech-Owl in Clowhom Watershed, March 2014
Clowhom Watershed Species at Risk and Habitat Surveys
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6.5 Other Species at Risk
Through the course of our wetland mapping and amphibian, turtle and owl surveys, we encountered
numerous other wildlife species, including birds, snakes, and mammals. In all, we recorded 66 vertebrate
species in the Clowhom watershed this project year (Table 9, pages 59/60).
In addition to the three listed amphibian and owl species (Red-legged Frog, Western Toad, Western
Screech-Owl), we also documented the presence of four other species at risk (Roosevelt Elk, Sooty
Grouse, Great Blue Heron, and Peregrine Falcon) (Figure 52).
Sooty Grouse
Roosevelt Elk
Great Blue Heron
Peregrine Falcon
Figure 52: Other Species at Risk Detected in Clowhom Watershed Year 1 (2013-2014)
Clowhom Watershed Species at Risk and Habitat Surveys
69
6.6 Planned Activities for Year 2 of this Project
This is a multi-year project. During Year 2 (2014-2015) we will build on our findings and expand our
survey efforts, to include the following activities:
Wetland and Riparian Classification and Mapping
•
Continue to identify, classify, delineate and map wetlands in the Clowhom watershed
•
Assess riparian habitat along the watershed’s creeks using a GIS approach to delineate
buffer habitat around each creek and evaluate land use and impacts in riparian zones
throughout the watershed
Species at Risk Surveys
•
Pond-breeding Amphibians: Continue egg mass, auditory and live trapping surveys
•
Western Screech-Owls: Continue call-playback surveys and nest searches
•
Northern Goshawks: Conduct call-playback surveys and nest searches
•
Coastal Tailed Frogs: Carry out hand searches and eDNA surveys in suitable creeks
•
Pacific Water Shrews: Conduct eDNA surveys in suitable potential habitat
•
Bats: Conduct acoustic and mist net surveys with focus on species at risk, including Little
Brown Myotis, Keen’s Long-eared Myotis, and Townsend’s Big-eared Bat
Multi-species Restoration and Enhancement Plans
•
Continue to prioritize sites for habitat protection, restoration, enhancement and threat
mitigation
•
Continue to work with partners, including government, Recovery Teams, expert and
stakeholders to develop detailed multi-species restoration and management plans
Public Education and Engagement
•
Write and distribute stewardship guides and design and install interpretive signs
•
Work with community members to build, install and monitor bat houses and owl nest boxes
•
Give presentations, meet with local groups
•
Landowner outreach and stewardship agreements
•
Media articles and project promotion
•
Meetings with partners in government, industry, conservation community
Clowhom Watershed Species at Risk and Habitat Surveys
70
7.0 RECOMMENDATIONS
A key goal of this project is to develop, implement, monitor and adaptively manage multi-species
restoration and enhancement plans. This is an ongoing activity over the four years of this project, as we
add more information, conduct further assessments, document species at risk, and evaluate habitat and
threats. Initial assessments and surveys in this first year of the project suggest that several of the
relatively few wetland habitats in the watershed are at risk of degradation due to anthropogenic activities.
Key habitat enhancement and threat mitigation priorities and opportunities are described in the sections
below. Specific recommendations for each of the 14 identified wetlands are outlined in Table 10.
1) Investigate Impacts of Water Level Fluctuations on Amphibians
Habitat for pond-breeding amphibians is somewhat limited within the Clowhom watershed, and much of
the habitat that does exist is less than ideal due to human impacts. One problematic issue facing several
key amphibian breeding sites is the dramatic and unpredictable variation in water levels due to hydro
activities (Figure 53). In wetlands immediately adjacent to the reservoir (Wetlands 9 and 10), rapidly
changing water heights are directly affecting several Western Toad and Red-legged Frog breeding sites.
Water level fluctuations can impact amphibian reproduction and survival in several ways. If water levels
are high during egg-laying season, amphibians are able to find suitable sites upon which to attach their
egg masses (there are ample willow branches when water levels are high). However, if water levels then
drop before the eggs can hatch, the egg masses will become stranded on land and will die.
If the water is severely drawn down at the time of egg-laying then there are insufficient attachment points
for egg masses and amphibians are forced to lay in very shallow pools which may dry out before tadpoles
or salamander larvae have sufficient time to complete their metamorphosis.
Rapid increases in water levels can wash away egg masses and inundate breeding sites with cold water
from the reservoir, impeding development of amphibian larvae. Inundation can also increase predation
risks by enabling fish to move into the formerly fish-free areas where amphibians prefer to breed.
The Red-legged Frog population in Clowhom appears to be very small compared with wetlands in other
areas of the Sunshine Coast. It is likely that the drastic water level fluctuations played a role in the
decline of this species in the basin.
It is unknown to what extent water level fluctuations are limiting to populations of amphibians, fish, and
invertebrates in the Clowhom watershed. These impacts likely depend upon the timing and magnitude of
rapid shifts in water levels. An analysis of reservoir levels through time would help determine what effects
water level variations are having on breeding amphibians.
The shíshálh (Sechelt) Nation and BC Hydro are undertaking a long term study of the large wetland
complex at the end of the reservoir. They have attempted various techniques to measure water level
changes directly; however, their instruments have failed due to freezing and extreme low water events.
The project leaders have indicated that they will now be using reservoir level and river discharge data,
combined with benchmarked elevations, to assess how the water levels in the wetland area are being
affected by hydro operations (Ferguson et al. 2012). This information will be invaluable in determining
what, if any, action needs to be taken to preserve or improve the amphibian habitat at this vital site.
Ultimately, the best way to mitigate the impacts of water level fluctuations would be to provide detailed
management recommendations related to timing, frequency and duration of inundation of specific
elevations, in relation to the life cycle timing of, at minimum, the two at risk amphibian species. Similar
methods and recommendations could potentially come from work on amphibian survivorship conducted
near the Mica Dam and within the Kinbasket and Arrow Lakes Reservoir (Hawkes and Tuttle 2013).
Clowhom Watershed Species at Risk and Habitat Surveys
71
Figure 53: Water Level Fluctuations in Wetland 9
Clowhom Watershed Species at Risk and Habitat Surveys
72
2) Investigate Pond Construction
To mitigate the problem of water level fluctuations, it may be possible to create stable habitats that will not
be subject to the same deleterious effects experienced by areas directly connected to the reservoir.
Ponds of various sizes could potentially be constructed in wetlands and riparian areas adjacent to those
currently being affected. Ideally, these ponds would be provide a diverse mixture of habitats, which would
support the greatest diversity of wildlife species. Specific areas would need to be assessed to determine
whether existing soils will retain water, and what ground and surface water sources exist. Since the area
is mostly sandy gravel fluvial substrate, it is likely that any constructed ponds will have to be lined with
some impervious material (ideally clay from a local source that will require little transport). Alternatively, if
sufficient hydrologic inputs exist, a constant inflow of water could compensate for rapidly draining
substrates. After specific sites are evaluated, ponds could be constructed in a few days with an
excavator. Re-vegetating excavated areas would help ensure that the created habitat becomes
functional in a short period of time.
3) Consider Establishment of a Wildlife Management Area Around Wetland 8/9
The wetland complex at the end of the reservoir (Wetland 8 and 9, Figure 54) is a significant location for
wildlife in the Clowhom watershed. This wetland complex incorporates a wide range of wetland classes
from bog, fen, marsh, and shallow water, to high, medium and low bank floodplain, and thus provides a
great variety of habitats. The site supports an impressive diversity of wildlife species from invertebrates,
to frogs, toads, salamanders, snakes, fish, breeding birds, ungulates, and carnivores (see Table 9 on
pages 59 and 60, and Bates (2007, 2008), Bates et al. (2009), Bates & Ferguson (2010), and Ferguson et
al. (2012)). In only our first year of surveys at this wetland, we documented the presence of four different
species at risk (Western Toad, Red-legged Frog, Sooty Grouse, and Roosevelt Elk). Turning this site into
a provincial Wildlife Management Area could provide some extra options as to how to manage this
valuable location for wildlife, while still leaving it available for some hunting as well as use by BC Hydro.
Figure 54: The Large Wetland Complex at the end of the Reservoir is Essential to Wildlife
Clowhom Watershed Species at Risk and Habitat Surveys
73
4) Address Threats Posed by Roads and Transmission Lines
Further threats to wetland wildlife and their habitats in the Clowhom watershed include transmission lines,
which cross at least seven wetlands, and roads, which run adjacent to several key habitats. Potential
impacts include road mortality, pollution from road runoff, invasive species introduction, and harm to
wildlife during right of way maintenance, brushing, and vegetation removal activities.
Road mortality is a significant issue for amphibians, particularly mass breeding species such as Western
Toads (Andrews et al. 2008). At present, the relatively light traffic and low density of migrating
amphibians in most areas in the valley means that the impact is likely to be minimal. However, there is
one site where mitigation measures may be necessary. At Wetland 7 (near Clowhom Main km 17) an
important high density Western Toad breeding site is located right next to the road (Figure 55). At
minimum, temporary road signage is recommended to raise awareness about the presence and season
of toad metamorphosis and migration. In the longer term, a combination of drift fencing to direct migrating
amphibians and a crossing structure (ideally a simple box culvert) could be implemented to reduce road
mortality impacts. Surveys in the 2014-2015 project year will help identify the routes used by dispersing
toadlets, and will inform any future mitigation measures.
Because transmission lines run over several Clowhom wetlands (including Wetland 7), these sites may be
subject to periodic brushing and vegetation removal. This activity may be beneficial or detrimental to
amphibians depending on how it is undertaken. If careful hand removal is practiced, clearing may be
beneficial to amphibians by maintaining sunny exposures and warm temperatures for larval development.
However these maintenance activities should be timed to avoid critical developmental periods for
amphibians. In addition, chemical herbicides should be avoided around these sites as they can be
acutely toxic to amphibians (Relyea 2005).
Roads and transmission lines also risk bring introduced, invasive and native weedy species to the area.
Invasive weeds detected in Clowhom wetlands include Canada Thistle (Cirsium arvense), Oxeye Daisy
(Leucanthemum vulgare), and Himalayan Blackberry (Rubus armeniacus). At present they seem to be
confined to the gravelly areas at the roadside and around the transmission poles. Further monitoring
should be undertaken to track the spread of these species and determine if removal is necessary.
Figure 55: Proximity of Clowhom Main FSR to Western Toad Breeding Site at Wetland 7
Clowhom Watershed Species at Risk and Habitat Surveys
74
5) Maintain Key Forest Areas for Species at Risk
Several species at risk, including Western Screech-Owls and Northern Goshawks, are associated with
mature forest and rely upon mature forest structural features. Suitable late successional forest habitat is
limited in the Clowhom watershed due to past logging activity. Future forest harvesting decisions should
seek to conserve and maintain habitat values for listed wildlife species around important breeding,
hibernating, nesting and foraging sites, and within identified territories.
For Western Screech-Owls, it is essential to maintain areas of low elevation late successional riparian
forest and the large diameter cavity-forming trees necessary for nesting. Thus far the species has been
detected along the Clowhom mainline at the following sites: kilometers 5, 8.5, 9, 14.5, 17 and 20.
Ongoing surveys in Year 2 of this project will help to further define the territories of Western Screech-Owl
pairs in the watershed.
Although not considered old growth dependent, Red-legged Frogs do require forested landscapes and
are negatively affected by clear cut logging (Maxcy 2004). Forest harvesting can also have detrimental
impacts on the hydrology, function, and productivity of wetlands used by this species (Richardson 1994).
The large scale forest harvesting in Clowhom likely contributed to a decline in Red-legged Frogs in the
watershed. To aid with the survival of this threatened species, it is vital to conserve forested areas
adjacent to known breeding ponds. Such forests provide the necessary cool, moist microclimatic
conditions and essential habitat structural features (e.g. coarse woody debris, understory vegetation)
used by emerging juveniles and foraging adults.
Wetland 6 (located off of Clowhom mainline at km 18.5; Figure 56) is a particularly important site for
breeding Red-legged Frogs. This site also appears to provide outstanding habitat for Pacific Water
Shrews and surveys in 2014/2015 will help to assess whether this endangered species is also present in
the wetland. The west side of Wetland 6 is undisturbed mature riparian forest containing very large Sitka
Spruce trees. This forest offers excellent habitat for many species of wildlife including Western ScreechOwls. Given its value to species at risk and other wildlife, efforts should be made to ensure there is no
future alteration of this forest habitat through harvest or any other industrial activities.
Figure 56: The Mature Riparian Forest Adjacent to Wetland 6 is Very Valuable to Wildlife
Clowhom Watershed Species at Risk and Habitat Surveys
75
6) Undertake Other Habitat Enhancement Activities
Other recommended habitat enhancement activities in Clowhom include the installation of woody debris
for amphibians and the installation of nest boxes for Western Screech-Owls.
Coarse woody debris, such as logs, stumps, and piles of bark, constitutes an essential microhabitat
component for amphibians. It provides a cool, moist environment, shelter from predators, and a source of
invertebrate prey (Whiles & Grubaugh 1998). At sites where coarse woody debris is limited, adding logs
and pieces of wood, especially large-diameter pieces in various stages of decay, could help improve
terrestrial habitat for amphibians.
Past forest harvesting in the Clowhom watershed has substantially decreased the number of standing
dead and dying trees, reducing availability of potential nest trees for diverse cavity-nesting wildlife
species, such as squirrels, flying squirrels, bats, woodpeckers, and owls. For threatened Western
Screech-Owls, the loss of cavity-bearing nest trees has been identified as one of the causes of population
declines in recent years (COSEWIC 2012) and the size of screech-owl populations in some regions is
limited by the number of available cavities (Belthoff & Richardson 1990).
One habitat enhancement option is to supply artificial cavities, in the form of nest boxes, where natural
tree cavities are lacking. Western Screech-Owls have been observed to readily accept man-made nest
boxes for both nesting and roosting (Cannings and Angell 2001, COSEWIC 2012, Figure 57). Best
Management Practices for Raptor Conservation during Urban and Rural Land Development in BC
(Demarchi & Bentley 2005) affirms that recommended restoration and enhancement measures include
replacing raptor nest sites that are damaged or lost and further states that "nest boxes in riparian areas
are especially important for Western Screech-Owls, where natural tree cavities are lacking." Thus, we
have commenced efforts to install manmade Screech-Owl nest boxes within the Clowhom watershed.
It should be noted that protection of mature forest areas, nest trees and snags is overwhelmingly
preferred to the creation of artificial nest boxes. Our nest box additions are not suggested as in any way
sufficient to counteract the effects of any further removal of forest habitat used by Western Screech-Owls
in the watershed. However, in areas where there is already an absence of suitable nest trees, the
addition of nest boxes may be a worthwhile interim enhancement measure. In the long-term, the addition
of nest boxes could potentially help to increase Western Screech-Owl nesting success and recruitment,
increasing the viability of owl populations in Clowhom.
Figure 57: Screech Owls will use Man-made Nest Boxes
Clowhom Watershed Species at Risk and Habitat Surveys
76
Table 10: Site-Specific Management Recommendations for Clowhom Watershed Wetlands
UTM
Wetland
Number
Datum: NAD 83
Location
UTM Zone: 10U
Easting
Northing
Enhancement / Mitigation Opportunities
1-3
Off Clowhom
Mainline km 24
470635
5520703
manage water levels; increase coarse woody
debris; mitigate road impacts; plant riparian
vegetation
4
Off Clowhom
Mainline km 20
471600
5517949
mitigate road impacts
5
Off Clowhom
Mainline km 20
471485
5517732
no restoration needed
6
Off Clowhom
Mainline km
18.5
471516
5516185
maintain nearby old growth riparian forest;
mitigate road mortality for migrating amphibians
7
Off Clowhom
Mainline km 17
5514951
mitigate road mortality; investigate toad road
crossing structure; monitor invasive species; take
care when clearing brush under transmission line
(hand removal), avoid chemical herbicides
8
North part of
large wetland
complex, end of
the reservoir
5514238
monitor invasive weeds (remove if spread);
maintain culverts; monitor human use does not
exceed current levels; investigate establishment
of Wildlife Management Area
9
Main part of
large wetland
complex, end of
the reservoir
469300
5513850
water level management through sensitive timing
of hydro operations; investigate excavation of
deep pools that will hold water during drawdown;
investigate establishment of Wildlife Management
Area
10
Small bay at
north end of
Clowhom
Reservoir, km
13.5
468522
5512698
water level management through sensitive timing
of hydro operations
11
Bear Creek
Mainline km 3.5
461334
5514003
control invasive species; mitigate road effects;
plant riparian vegetation
12
Bear Creek
Mainline km 3.5
460969
5513977
consider planting riparian vegetation and
providing large woody debris with smaller
branches
13
Bear Creek
Mainline km 6
459354
5515182
monitor road impacts
14
Off Clowhom
Mainline km 2
460796
5506688
remove invasive plants; monitor water quality
470474
469222
Clowhom Watershed Species at Risk and Habitat Surveys
77
8.0 ACKNOWLEDGEMENTS
Our sincere appreciation to the shíshálh Nation for allowing us access to their lands and for providing
letters of support for the project.
We gratefully acknowledge the financial support of the Fish and Wildlife Compensation Program on
behalf of its program partners BC Hydro, the Province of BC, Fisheries and Oceans Canada and the
public. Thanks to FWCP and BC Hydro staff, especially Lorraine Ens, Allister McLean, Patrice Rother,
and Alexis Hall, for their guidance and logistical support. Additional funding for this project came from
Environment Canada, Gencon Foundation, Canadian Wildlife Foundation, Public Conservation
Assistance Fund, and the Habitat Conservation Trust Foundation.
We are indebted to Veresen Incorporated and Clowhom Power LP for their generous in kind contributions
of boat transportation, accommodation in the watershed, and use of their truck. Thanks especially to
William McDonagh, Robert Kulka, Kyle Edwards, Kyle Saylor, and Luke Till.
Our heartfelt gratitude also to Regional Power and Bear Hydro LP for transporting our pick-up truck up
the inlet by barge, and for use of their accommodation and vehicle in Clowhom. Special thanks to James
Florance, David Carter, and Babar Khan.
The Sunshine Coast Wildlife Project has a long standing history with the Iris Griffith Interpretive Centre
and the amazing folks at the Ruby Lake Lagoon Nature Reserve Society and we thank them for their
ongoing encouragement and administrative and logistical support.
Several individuals provided expert advice and guidance to us throughout this study. Our gratitude to
Dave Bates for generously sharing information about Clowhom based on his years of experience working
in the watershed. Thanks to Jared Hobbs for his valuable and critical review of our proposal and work
plan and for unreservedly sharing his expert knowledge about Western Screech-Owls. Our appreciation
to Erica McClaren for providing a highly valuable Northern Goshawk training session. We are very
thankful for guidance and in-kind contributions from numerous BC Ministry of Forests, Lands and Natural
Resource Operations staff members, including Species at Risk Biologist Kym Welstead, Provincial Bird
Specialist Myke Chutter, Resource Stewardship Manager Scott Barrett, and Wildlife Manager Darryl
Reynolds. Thanks also to BC Ministry of Environment Small Mammal and Herpetofauna Specialist and
BC Frogwatch Coordinator, Purnima Govindarajulu, for her continuing support and advice.
We could not have accomplished so much on this project without the superior skills and dedication of our
exceptional project team. Aimee Mitchell and Chris Currie provided outstanding leadership and
professionalism in the field. Field assistants Jennifer Sibbald and Kaiden Bosch worked with great
enthusiasm during long days and nights in the field. Anayansi Cohen-Fernandez provided the most
wonderful outreach and education program imaginable. Lou Drumond and Rick O’Neill built beautiful owl
and bat houses and construction kits. The first-class graphic design talents of Maya Birkel helped make
our signs and outreach materials look lovely. Thanks to all of the community members and school kids
who helped us built owl houses this year.
Almost all photos in this document were taken by Aimee Mitchell, Chris Currie, Dave Stiles, Michelle
Evelyn and Kaiden Bosch. The few exceptions, provide courtesy of Creative Commons licences, are on
page 69: Sooty Grouse (Jerry Oldenettel), Great Blue Heron (Bruce Irschick), Roosevelt Elk (Linda
Tanner), and Peregrine Falcon (Evan Bornholtz) and on page 76: Screech Owl in Nest Box (Amanda
aeh223).
Clowhom Watershed Species at Risk and Habitat Surveys
78
9.0 REFERENCES
Andrews KM, Gibbons JW, and Jochimsen DM (2008) Ecological effects of roads on amphibians and
reptiles: a literature review." Herpetological Conservation 3: 121-143.
Austin MA, Buffett DA, Nicolson DJ, Scudder GGE and Stevens V (eds.) (2008) Taking Nature’s
Pulse: The Status of Biodiversity in British Columbia. Biodiversity BC, Victoria, BC. 268 pp.
Available at: www.biodiversitybc.org
Bates DJ (2008) Clowhom Lake Water Use Plan – Clowhom Lake wildlife census – Year 2. Resource
Management Department, shíshálh Nation, Sechelt, BC.
Bates DJ (2007) Clowhom Lake Water Use Plan – Clowhom Lake wildlife census – Year 1. Resource
Management Department, shíshálh Nation, Sechelt, BC.
Bates DJ, Ferguson G (2010) Clowhom Lake Water Use Plan – Clowhom Lake wildlife census – Year 4.
Resource Management Department, shíshálh Nation, Sechelt, BC.
Bates DJ, Staats M, Ferguson G (2009) Clowhom Lake Water Use Plan – Clowhom Lake wildlife
census – Year 3. Resource Management Department, shíshálh Nation, Sechelt, BC.
Bates DJ, Ferguson G, Coombes O (2011) Clowhom Lake Water Use Plan - Clowhom Lake Wildlife
Census– Wildlife Rotation 2 – Year 1. Resource Management Department, shíshálh Nation, Sechelt, BC.
Belthoff JR, Ritchison G (1990) Nest-site selection by Eastern Screech-Owls in central Kentucky.
Condor 92: 982-990.
BC Ministry of Environment (2005) Guidelines for Raptor Conservation during Urban and Rural Land
Development in British Columbia (2005)
BC Ministry of Forests and Range & BC Ministry of Environment (2010) Field Manual for Describing
nd
Terrestrial Ecosystems, 2 Edition. Land Management Handbook #25.
Bridge-Coastal Restoration Program (2000) Strategic Plan, Volume 2, Watershed Plans, Chapter 14:
Clowhom River. (December 2000).
Cannings RJ, Angell T (2001) Western Screech-Owl (Otus kennicottii). In: The Birds of North America,
No 597 (A. Poole and F. Gill eds.). The Birds of North America, Inc., Philadelphia, PA.
Cornell Lab of Ornithology Nestwatch Program (2013) Nest Box Construction Plans: American
Kestrel, Screech Owl, and Northern Saw-whet Owl.
COSEWIC (2002a) COSEWIC assessment and status report on the red-legged frog Rana aurora.
Committee on the Status of Endangered Wildlife in Canada. Ottawa.
COSEWIC (2002b) COSEWIC assessment and status report on the western toad Bufo boreas in
Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa.
COSEWIC (2006) COSEWIC assessment and status report on the Western Painted Turtle Chrysemys
picta bellii (Pacific Coast population, Intermountain-Rocky Mountain population and Prairie/Western
Boreal - Canadian Shield population) in Canada.
Clowhom Watershed Species at Risk and Habitat Surveys
79
COSEWIC (2012) COSEWIC assessment and status report on the Western Screech-Owl kennicottii
subspecies Megascops kennicottii kennicottii and the Western Screech-Owl macfarlanei subspecies
Megascops kennicottii macfarlanei in Canada. Committee on the Status of Endangered Wildlife in
Canada. Ottawa.
Davis H, Weir R (2008) Western Screech-Owl Conservation along the Shuswap River. Final Report to
BC Hydro, BCRP Project # 07.W.SHU.01
Demarchi MW, Bentley MD (2005) Best management practices for raptor conservation during urban and
rural land development in British Columbia. Prepared for B.C. Ministry of Environment.
Dulisse J, Beaucher M-A (2006) 2005 Western Screech-Owl inventory of the Central and West
Kootenay Region. Unpublished report, Columbia Basin Fish & Wildlife Compensation Program.
Elliott K (2006) Declining numbers of Western Screech-Owl in the lower mainland of British Columbia.
British Columbia Birds 14:2-11.
Environment Canada (2005) Sensitive Ecosystems Inventory of the Sunshine Coast and Adjacent
Islands.
Ferguson G, Iredale F (2007) Inventory of Western Screech-Owl in the Thompson Region. BC Ministry
of Environment.
Ferguson G, Bates DJ, Coombes O (2012) Clowhom Project Water Use Plan - Monitor of Aquatic
Wildlife in Wetland affected by Dam Operations Implementation Year 6. Reference: COMMON-1
Year 2 – Rotation 2: Clowhom Lake Wildlife Census Study Period: April 1, 2011 to March 31, 2012.
Resource Management Department, shíshálh Nation, Sechelt, BC.
Fish and Wildlife Compensation Program (2011) Clowhom Watershed – Watershed Plan. (October
2011).
Green RN, Klinka K (1994) A Field Guide to Site Identification and Interpretation for the Vancouver
Forest Region. Land Management Handbook #28, BC Ministry of Forests.
Hausleitner D (2006) Inventory Methods for Owl Surveys. Standards for Components of British
Columbia’s Biodiversity No.42. Prepared for Ecosystems Branch of the Ministry of Environment for the
Resources Information Standards Committee. Victoria, B.C.
Hausleitner D, Young V, Tripp T (2007) Inventory and habitat enhancement of Western Screech and
Flammulated Owls in the Bridge Coastal Study Area: Final Report. Unpublished report, BC Hydro Bridge
Coastal Fish and Wildlife Restoration Program.
Hobbs J (2013a) Western Screech-Owl Conservation and Management for the Bridge-Seton Area 2012
Survey - Final Report. March 10, 2013.
Hobbs J (2013b) Western Screech Owl Conservation and Management in the Flathead River Basin
(2012 Surveys-Final Report). March 12, 2013.
Hobbs J (2013c) Western Screech Owl Conservation and Management in the Thompson & Okanagan
Regions (2012 Surveys-Final Report). March 11, 2013.
Hawkes VC, Tuttle KN (2013) CLBMON-37. Kinbasket and Arrow Lakes Reservoirs: Amphibian and
Reptile Life History and Habitat Use Assessment. Year 5 Annual Report – 2012. LGL Report EA3303.
Unpublished report by LGL Limited environmental research associates, Sidney, BC, for BC Hydro
Generations, Water License Requirements, Burnaby, BC.
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IUCN (2014) The IUCN Red List of Threatened Species. Version 2014.1. <http://www.iucnredlist.org>.
Downloaded on 12 June 2014.
Kaufman K (2002) A Little Night Magic”. In Audubon Magazine January-February 2002.
Kissling ML, Lewis SB (2009) Distribution, abundance and ecology of forest owls in Southeast Alaska.
U.S. Fish and Wildlife Service, Juneau Field Office, Alaska, and Alaska Department of Fish and Game,
Division of Wildlife Conservation, Douglas, Alaska.
MacKenzie WH, Moran JR (2004) Wetlands of British Columbia: A guide to identification. Land
Management Handbook #52, BC Ministry of Forests.
Maxcy KA (2004) Accounts and Measures for Managing Identified Wildlife – Accounts V.2 Red-legged
Frog Rana aurora aurora. BC Ministry of Water, Land and Air Protection, Victoria, BC.
Olson DH, Leonard WP, Bury RB (1997) Sampling Amphibians in Lentic Habitats: Methods and
Approaches for the Pacific Northwest. Northwest Fauna Number 4. Society for Northwestern Vertebrate
Biology, Olympia, WA.
Ovaska, KS, Sopuck L, Engelstoft C, Matthias L, Wind E (2004) Best Management Practices for
Amphibians and Reptiles in Urban and Rural Environments in BC. Ministry of Water Land and Air
Protection.
Relyea RA (2005) The impact of insecticides and herbicides on the biodiversity and productivity of
aquatic communities. Ecological Applications 15: 618–627.
Resource Information Standards Committee (1998) Inventory Methods for Pond-breeding Amphibians
and Painted Turtle. BC Ministry of Environment, Ecosystems Branch. Published by the Terrestrial
Ecosystems Task Force Resources Information Standards Committee, Victoria, B.C.
Richardson CJ (1994) Ecological functions and human values in wetlands: a framework for assessing
forestry impacts. Wetlands 14: 1–9.
Scott NJ, Woodward BD (1994) Surveys at breeding sites. Pp 118-125 In Measuring and monitoring
biological diversity: standard methods for amphibians. Smithsonian Institution Press, Washington, DC.
Tori GM et al (2002) Wetland conservation and Ducks Unlimited: Real world approaches to multispecies
management. Waterbirds 25: 115-121.
Western Painted Turtle Recovery Team (2014) Draft Recovery Strategy for the Western Painted Turtle
(Pacific Coast Population), Chrysemys picta bellii, in British Columbia (April 2014).
Whiles MR, Grubaugh JW (1996) Importance of coarse woody debris to southern forest
herpetofauna. Biodiversity and coarse woody debris in southern forests. USDA Forest Service, Asheville,
NC, 94-100.
Clowhom Watershed Species at Risk and Habitat Surveys
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10.0 CONFIRMATION OF FWCP RECOGNITION
Figure 58: Acknowledgement of FWCP on Amphibian and Owl Interpretive Signs
Clowhom Watershed Species at Risk and Habitat Surveys
82
Figure 59: Acknowledgement of FWCP on Sunshine Coast Wildlife Project Brochure
Figure 60: Acknowledgement of FWCP in Facebook article about Clowhom Project
Clowhom Watershed Species at Risk and Habitat Surveys
83
Figure 61: Acknowledgement of FWCP on SCWP Web Site Home Page
Figure 62: Acknowledgement of FWCP on SCWP Web Site Sponsors’ Page
Clowhom Watershed Species at Risk and Habitat Surveys
84
Figure 63: Acknowledgement of FWCP in Sunshine Coast Wildlife Project Winter Newsletter
Figure 64: Article in the Salal (Sunshine Coast Botanical Garden Newsletter)
Clowhom Watershed Species at Risk and Habitat Surveys
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Figure 65: Article in Marsh Wrenderings (Sunshine Coast Natural History Society Newsletter)
Clowhom Watershed Species at Risk and Habitat Surveys
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11.0 APPENDICES
Appendix 1: Data Collected during Comprehensive Wetland Surveys
Survey Area
Amphibian survey conducted?
Wetland ID
Vegetation survey conducted?
Wetland Name
Hydrology comments
Location
Has the wetland previously been impacted
Coordinate Datum
Comments on previous impacts
UTM Zone
Does the wetland flow directly into a creek?
UTM East coordinates
Comments on potential restoration activities
UTM North coordinates
Is the wetland located in a drinking water catchment?
General access
Wildlife observed
Comments on access
Potential for amphibian breeding
Date of first survey
Were species at risk observed?
Mapping type
Which species at risk were observed
Dominant wetland subclass
Wetland health ranking
Wetland subclass 1
Wetland degradation ranking
Wetland subclass 2
Invasive species ranking
Wetland subclass 3
Aesthetic ranking
Average water depth
Probability of future impacts ranking
Maximum water depth
Wetland function ranking
Elevation
Wetland wildlife sign ranking
Aspect
Overall wetland rating from summing measures
Slope
Overall wetland rating using categories
Water temperature
Air temperature
What type of amphibian survey was conducted?
Rana aurora detected (Y/N)
pH
Pseudacris regilla detected (Y/N)
Soil moisture regime
Ambystoma gracile detected (Y/N)
Soil nutrient regime
Taricha granulosa detected (Y/N)
Moisture subclass
Ambystoma macrodactylum detected (Y/N)
Organic soil texture
Anaxyrus boreus detected (Y/N)
Organic soil depth
Potential habitat for Anaxyrus boreus
Mineral soil texture
Chrysemis picta detected (Y/N)
Structural stage
Name of Plant Community(ies)
Hydrology classification
Listed Plant Community
Biogeoclimatic Zone
Comments
Area of wetland
Clowhom Watershed Species at Risk and Habitat Surveys
87
Appendix II: Qualitative Wetland Evaluation Rankings
Health and Vigor
1 - Very Poor
Area highly impacted. Very limited regeneration and/or growth of native plant species.
2 - Poor
Area obviously impacted. Limited but some regeneration and/or growth of native plant species.
3 - Good
Area moderately impacted. Regeneration and growth of native plants occurring but not vigorously.
Growth and regeneration appears to be suppressed.
4 - Very Good
Very few impacts observed. Impacts very limited in extent and affect. Otherwise healthy growth and
regeneration of plants observed.
5 - Excellent
No impacts to health and vigor observed, healthy growth and regeneration of native plants.
Site Degradation
1 - Very Poor
Site completely altered from natural state. Chance of natural successional processes reversing
degradation minimal. Significant restoration activities required to reverse impacts.
2 - Poor
Site has been significantly degraded, through dramatic changes to hydrology, vegetation, or soils.
Requires restoration activities to manage impacts.
3 - Good
Site has had some degradation such as vegetation removal, or hydrological alterations. Overall
degradation can be reversed quickly through restoration activities or natural processes
4 - Very Good
Degradation limited to adjacent areas, or very slight changes within the site. Natural processes
sufficient to restore site.
5 - Excellent
Site is pristine. No anthropogenic alteration.
Aesthetics
1 - Very Poor
Area has been highly impacted and has little aesthetic value
2 - Poor
Area has been highly impacted and has limited aesthetic value but may contain some interesting and
“beautiful” natural features. features
3 - Good
Although impacted, area has retained some aesthetic value and contains several interesting and
“beautiful” natural features.
4 - Very Good
Area very aesthetic and contains many interesting and “beautiful” natural features.
5 - Excellent
Area has a natural beauty that appears to be pristine.
Clowhom Watershed Species at Risk and Habitat Surveys
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Chance of No Future Impact
1 - Very Poor
Area identified for development. Area impacted frequently. Area in a very accessible location.
2 - Poor
Area likely to be impacted based on its accessibility. Ongoing moderate impacts (i.e. limited roads,
right of ways) evident.
3 - Good
Human access appears to be limited but may be evident. Area may be considered for resource
extraction in the future. Ongoing light impacts (e.g. recreational use) evident.
4 - Very Good
Area fairly remote and not located close to roads or trails. Human access unlikely or uncommon. Area
not ideal for resource extraction or recreation.
5 - Excellent
Area is in a remote location and access difficult. Area protected under park or other legislation.
Site Function
1 - Very Poor
Ecological processes no longer functioning. Site provides limited to no flood control or water filtration.
Provides very poor to no habitat for native wildlife.
2 - Poor
Ecological processes severely impeded by past/ongoing degradation. Site provides very little flood
control, water retention and habitat.
3 - Good
Ecological processes impeded by past/ongoing degradation. Site provides some flood control, water
retention and habitat.
4 - Very Good
Ecological processes largely recovered from past degradation. Area will provide flood control, water
retention, water filtration and quality wildlife habitat.
5 - Excellent
Ecological processes unimpeded. Site provides flood control, water filtration, excellent wildlife habitat.
Wildlife Sign
1 - Very Poor
Very low abundance and diversity of wildlife.
2 - Poor
Few signs of wildlife. Low diversity.
3 - Good
Average abundance and diversity of wildlife.
4 - Very Good
Evidence of frequent use by multiple species. Some evidence of breeding wildlife.
5 - Excellent
Numerous, conspicuous signs of multiple taxa, including rare or threatened species. Evidence
constant use. Very productive site for breeding wildlife.
Introduced / Invasive Species
1 - Very Poor
Invasives dominant. Removal may require significant effort, through mechanical or chemical means.
2 - Poor
Invasives established, but not dominant. Removal recommended.
3 - Good
Few invasives, limited to perimeter of wetland, or nearby sites.
4 - Very Good
No invasive species present. Few introduced species limited to perimeter.
5 – Excellent
No invasive or introduced species present.
Clowhom Watershed Species at Risk and Habitat Surveys
89
Appendix III: Wetland Plant Lists for Clowhom Wetlands
Species Name
Common Name
Wetland Number
6
7
8
9
3
4
5
D
R
C
C
R
R
R
C
C
C
C
R
D
R
R
R
R
R
R
R
C
C
C
10
14
Trees
Acer macrophyllum
Alnus rubra
Picea sitchensis
Pinus contorta var. Contorta
Pseudotsuga menzeisii
Thuja plicata
Tsuga heterophylla
Tsuga mertensiana
bigleaf maple
red alder
Sitka spruce
shore pine
Douglas-fir
western red-cedar
western hemlock
mountain hemlock
R
R
R
R
R
R
R
R
C
R
R
R
R
Shrubs
Gaultheria shallon
Kalmia microphylla
Ledum groenlandicum
Lonicera involucrata
Meziesia ferruginea
Oplopanax horridus
Oxycoccus oxycoccos
Rhamnus purshiana
Ribes bracteosum
Rubus discolor
Rubus parviflorus
Rubus spectabilis
Rubus ursinus
Salix spp.
Sambuca recemosa
Spiraea douglasii
Vaccinium alaskaense
Vaccinium membranaceum
Vaccinium ovalifolium
Vaccinium parvifolium
Viburnum edule
salal
western bog-laurel
Labrador tea
black twinberry
false azalea
devil's club
bog cranberry
cascara
stink currant
Himalayan blackberry
thimbleberry
salmonberry
trailing blackberry
willow (various species)
red elderberry
hardhack
alaskan blueberry
black huckleberry
oval-leaved blueberry
red huckleberry
highbush-cranberry
R
C
C
R
C
R
R
R
R
C
R
D
R
R
C
C
R
D
C
C
R
R
R
C
R
C
R
C
C
R
R
R
R
C
R
R
R
C
C
D
C
C
R
C
C
C
R
R
Ferns, Forbs and Graminoids
Adiantum pedatum
Athyrium felix-femina
Agrostis aequivalvis
Anaphalis margaritacea
Aster subspicatus
Blechnum spicant
Boykinia elata
Calamagrostis canadensis
Carex canescens
Carex lenticularis var lipocarpa
Carex lenticularis var lenticularis
Carex obnupata
Carex pauciflora
Carex pluriflora
Carex rostrata
Carex sitchensis
Carex stipata
Carex viridula
Cirsium edule
maidenhair fern
lady fern
Alaska bentgrass
pearly everlasting
Douglas aster
deer fern
coast boykinia
bluejoint
grey sedge
Kellogg's sedge
lakeshore sedge
slough sedge
few-flowered sedge
several-flowered sedge
beaked sedge
Sitka sedge
sawbeak sedge
green sedge
edible thistle
R
R
C
C
R
R
R
R
R
R
C
R
R
R
R
C
R
D
D
D
D
R
C
C
D
R
R
R
R
C
R
R
C
C
R
R
R
D
R
D = Dominant >30% coverage; C = Common between 5% and 30% coverage; R = Rare <5% coverage
Clowhom Watershed Species at Risk and Habitat Surveys
90
Species Name
Common Name
3
4
5
Wetland Number
6
7
8
9
10
14
Ferns, Forbs and Graminoids continued
Siberian miner's-lettuce
Claytonia sibirica
bunchberry
Cornus canadensis
great sundew
Drosera angelica
round-leaved sundew
Drosera rotundifolia
Eliocharis spp.
unknown spike rush species
fireweed
Epilobium angustifolium
purple-leaved willowherb
Epilobium cilatum
common horsetail
Equisetum arvense
scouring-rush
Equisetum hyemale
narrow-leaved cotton grass
Eriophorum angustifolium
cleavers
Gallium aparine
large-leaved avens
Geum macrophyllum
tall managrass
Glyceria elata
bog St. John's-wort
Hypericum anagalloides
tapered rush
Juncus accuminatus
common rush
Juncus effusius
dagger-leaved rush
Juncus ensifolius
spreading rush
Juncus supiniformis
wall lettuce
Lacuta muralis
partridgefoot
Leutkia pectinata
skunk cabbage
Lysichiton americanum
false lily-of-the-valley
Maianthemum dilatatum
field mint
Mentha arvensis
buckbean
Menyanthes trifoliata
yellow pond-lily
Nuphar polysepalum
Pacific water-parsley
Oenanthe sarmentosa
white bog-orchid
Planthera dilatata
slender bog-orchid
Planthera stricta
Pacific sword fern
Polystichum munitum
floating-leaved pondweed
Potamogeton natans
self-heal
Prunella vulgaris
lesser spearwort
Ranunculus flamula
white beaked sedge
Rhyncospora alba
wool-grass
Scirpus cyperinus
small-flowered bullrush
Scirpus microcarpus
scheuchzeria
Scheuchzeria paulustris
narrow-leaved bur-reed
Sparganium angustifolium
rosy twistedstalk
Streptopus roseus
fringecup
Tellima grandiflora
foamflower
Tiarella trifoliata
cattail
Typha latifolia
Veronica beccabunga ssp. Americana American brooklime
stream violet
Viola glabella
trailing yellow violet
Viola sempervirens
R
C
R
R
R
D
D
R
R
R
R
R
R
C
C
D
R
R
R
C
C
D
R
C
R
D
R
R
D
R
C
C
C
C
R
D
C
C
C
C
C
D
R
C
C
C
R
R
C
C
R
R
C
D
D
D
D
C
D
C
D
C
R
C
R
R
R
C
C
C
R
C
C
Bryophytes
Conocephalum conicum
Kindbergia oregana
Hylocomium splendens
Polytrichum juniperium
Sphagnum s p.
Sphagnum capillifolium
Sphagnum lindbergii
Rhytideadelphus laureus
snake liverwort
Oregon beaked moss
step moss
juniper haircap moss
Unknown Sphagnum spp.
small red peat moss
brown-stemmed bog moss
red-stemmed feather moss
R
C
C
C
R
C
C
R
R
R
D
C
C
C
C
R
C
R
D = Dominant >30% coverage; C = Common between 5% and 30% coverage; R = Rare <5% coverage
Clowhom Watershed Species at Risk and Habitat Surveys
91