Download Amphibians and Reptiles in Oregon: Oregon Spotted Frog

Appendix G –
Amphibians and Reptiles in Oregon: Oregon Spotted Frog, Columbia
Spotted Frog, Western Pond Turtle, and Western Painted Turtle.
This appendix discusses four amphibians and reptiles that likely will be listed as threatened or
endangered pursuant to the Endangered Species Act: the Oregon spotted frog, the Columbia
spotted frog, the Western pond turtle, and the Western painted turtle.
I.
The Oregon Spotted Frog
The Oregon spotted frog has been lost from at least 78 percent of its former range.1 In 1993, the
USF&WS determined the Oregon spotted frog warranted ESA listing however it has remained a
candidate species ever since.2 A status review was conducted in December 2007 which has been
updated annually through 2010.3 The species is known to exist in 43 sites in the United States,
31 of which are in Oregon, and 89 percent of which are in partial public ownership. USF&WS
states that due to its small populations in these sites, many of them are at “risk of extirpation
from stochastic events.”4 Pesticides are known to “negatively affect various life stages of a wide
range of amphibian species, including ranid frogs[.]”5 For this reason USF&WS notes that
In 1999, Four Rivers Vector Control planned to apply pyrethroids, methoprene,
and other pesticides in wetlands and other bodies of water within the range of the
Oregon spotted frog. This company is funded primarily by homeowners,
homeowner associations, and businesses in the Sunriver area of Oregon to control
mosquitoes. Due to the concerns about the use of methoprene and the possible
effects of the mosquito abatement program on the Oregon spotted frog, the
company is not permitted to use the chemical on the Deschutes National Forest
and is voluntarily restricting its use to a few sites. Similar proposals are possible
in the future.6
That restriction on pesticide applications was established over 12 years ago and there is no
evidence that any other such restrictions have been placed on either public or private lands to
provide protection for the Oregon spotted frog, a species for which ESA-listing is warranted and
for which the USF&WS has concluded “threats to this species are imminent[.]”7
1
USF&WS, Species Fact Sheet, Oregon spotted frog, Rana pretiosa,
http://www.fws.gov/oregonfwo/Species/Data/OregonSpottedFrog/ (last accessed July 27, 2012).
2
Id.
3
USF&WS, U.S., Fish and Wildlife Service Species Assessment and Listing
Priority Assignment Form, Common Name: Oregon spotted frog (April 2010) available at
http://ecos.fws.gov/docs/candforms_pdf/r1/D02A_V01.pdf (last accessed July 27, 2012).
4
Id. at 38.
5
Id. at 29.
6
Id. at 29-30.
7
Id. at 39.
II.
The Columbia Spotted Frog
Similarly, the Columbia spotted frog was determined by USF&WS to warrant threatened status
under the ESA but in 1993 that listing was precluded by higher priority actions and it has
remained on the candidate list ever since.8 Of the three states in which the Columbia spotted frog
lived historically, it is now found in a total of seven counties in the United States, three of which
are in Oregon (Lake, Harney, and Malheur).9 Ninety percent of the lands with known habitat are
federally managed by the U.S. Forest Service or Bureau of Land Management.10 USF&WS has
noted that the Columbia spotted frog populations have “continued to decline . . . despite the
analyses pursuant to N[ational]E[nvironmental]P[olicy]A[ct] on all Federal actions potentially
affecting the Columbia spotted frog and analyses pursuant to NEPA on public lands.”11 As an
indication of the vulnerability of this species to extinction, Oregon has classified the Oregon
spotted frog as imperiled and vulnerable to extirpation and extinction in the State.
USF&WS expresses concern about the use of pesticides where they can expose the Columbia
spotted frogs:
Use of pesticides for control of grasshoppers (Melanoplus sp.) and crickets
(Anabrus simplex), as well as use of herbicides to treat weeds and other
vegetation, may be impacting some populations of Columbia spotted frogs,
particularly on private property. While we have no evidence to suggest frogs have
been directly affected in the past, we do know substantial amounts of carbaryl
(used in insecticide applications) and atrazine (used in herbicide applications) are
used in Nevada and Idaho (Idaho State Department of Agriculture 2009).
Atrazine, even if used at levels below USEPA requirements, can cause changes in
the sex ratio in amphibians (Hayes 2004, pp. 1138-1147).12
The USF&WS is also concerned about the additive and synergistic effects of pesticides and other
adverse conditions, such as the effect of UV light on increasing the toxicity of chemicals and
increasing the susceptibility of individual frogs to infection, disease, or predation.13 The agency
concludes that “[T]he current state of small fragmented populations of Columbia spotted frogs in
the Great Basin indicates a high probability of populations disappearing[.]”14
8
USF&WS, U.S. Fish and Wildlife Service Species Assessment and Listing Priority
Assignment Form, Common Name: Columbia spotted frog (Great Basin Distinct Population
Segment) (April 15, 2010) available at http://ecos.fws.gov/docs/candforms_pdf/r8/D027_V01.pdf
(last accessed July 28, 2012).
9
Id. at 2.
10
Id. at 3.
11
Id. at 22.
12
Id. at 25.
13
Id. at 26.
14
Id.
III.
The Western Pond Turtle
There are two native species of turtles in Oregon, the Western pond turtle and the Western
painted turtle.15 ODFW states that “[b]oth are highlighted in the Oregon Conservation Strategy
as species in need of help—that is, they have low or declining populations.”16 ODFW has
designated both native turtles “Sensitive Species – Critical.”17 This designation means that both
native turtles are “naturally-reproducing fish and wildlife species, subspecies, or populations
which are facing one or more threats to their populations and/or habitats.”18 And, as stated
above, the designation “critical” means that both of these species are imperiled with local
extirpations and at risk of needing to be listed as threatened or endangered because the
population of Western Pond Turtles “has declined dramatically.”19 Moreover
The greatest danger facing Oregon's Western Pond Turtle population is low
juvenile recruitment. The species requires accessible upland nesting habitat near
their aquatic habitat. Fragmentation of properties and of land-use types renders
this critical habitat requirement increasingly rare. While relatively large
populations of mature turtles can be observed in their aquatic habitat, the rate of
successful breeding and juvenile recruitment is largely unknown and believed to
be too low to maintain population numbers at their current levels. In other words,
existing populations in Oregon are likely getting older and few juveniles survive
to replace their numbers.20
The Center for Biological Diversity recently filed a petition with the Secretary of the Interior to
list, inter alia, the Western pond turtle as endangered under the ESA.21 According to the petition,
“only northern California and southern Oregon support large populations but even in those areas
their status is uncertain.”22 Moreover
In Oregon, the western pond turtle occurs widely but in low to very low densities
(Holland 1993). Researchers observed the turtles in 83 of 313 sites surveyed in
15
ODFW, Turtles in Oregon, http://www.dfw.state.or.us/conservationstrategy/
turtles.asp (last accessed July 27, 2012).
16
Id.
17
ODFW, 2008 ODFW Sensitive Species List, organized by category 9, available at
http://www.dfw. state.or.us/wildlife/diversity/species/docs/SSL_by_category.pdf (last accessed
July 26, 2012).
18
Id. at 1.
19
University of Oregon Environmental Leadership Program, Western Pond Turtles:
Habitat and History in Oregon, http://pages.uoregon.edu/ecostudy/elp/turtle/oregon.html (last
accessed July 25, 2012).
20
Id.
21
Center for Biological Diversity, Petition to List 53 Amphibians and Reptiles in
the United States as Threatened or Endangered Species Under the Endangered Species Act, (July
11, 2012) available at www.biologicaldiversity.org/campaigns/amphibian_conservation/pdfs/
Mega_herp_petition_7-9-2012.pdf.
22
Id. at 90.
1991 (Holland 1993). In the Willamette Valley in Oregon, western pond turtles
appear to have declined to a level that represents roughly one percent of historic
levels (Holland 1991a).23
As the petition comments
The western pond turtle has special status under state law within its entire native
range (Bury and Germano 2008). It is listed as state endangered in Washington,
sensitive/critical in Oregon, and a species of special concern in California. But
none of these laws confer effective protection of habitat. Some successful
recovery actions have occurred in Washington and a conservation strategy drafted
for California, but these initiatives are merely voluntary and must be considered
inadequate (Allen et al. 2001, Ashton and Welsh Jr. 2009, vander Haegen et al.
2009).24
DEQ’s failure to ensure protection of this potentially endangered species from regulated
discharges of pesticides demonstrates precisely how poorly the Western states have failed.
USF&WS is concerned about the impacts of pesticides on the Western pond turtle. The agency
investigated pesticide use in the Willamette Valley National Wildlife Refuge Complex where
“much of the land within the refuge is managed for grass production involving applications of
herbicides, fungicides, and fertilizers.”25 The investigation concluded “there could be effects to
aquatic communities from exposure to atrazine and chlorpyrifos” and that “hormone values
measured in biotic samples from refuge sites were within normal ranges except for western pond
turtles at Finley National Wildlife Refuge, where higher testosterone values were observed in
females and the female hormone ratio was atypically low compared to reference turtles.”26 The
agency concluded “[t[he pesticides of most serious concern originate outside the refuge, and
refuge personnel have limited ability to manage pesticide application occurring off-refuge
lands.”27
IV.
The Western Painted Turtle
As stated above, ODFW classifes the Western painted turtle as “sensitive-critical.” “Threats to
western painted turtles in Oregon are very similar to western pond turtles and are often
landscape-specific.”28 Among the threats to the Western painted turtle are “indirect effects of
23
Id.
24
Id. at 92.
25
USFWS, Assessment of Impacts to Aquatic Organisms from Pesticide Use on the
Willamette Valley National Wildlife Refuge Complex, Pesticides and Aquatic Organisms (May
2007) http://www.fws.gov/oregonfwo/Contaminants/FieldStudies/ FinleyNWR/default.asp (last
accessed July 30, 2012).
26
Id.
27
Id.
28
U.S. Department of the Interior, Conservation Assessment For The Western
Painted Turtle In Oregon (Chrysemys picta bellii) Version 1.1 (September 2009) available at
http://www.fs.fed.us/r6/sfpnw/issssp/documents/planning-docs/ca-hr-chrysemys-picta-bellii-200
9-09.pdf.
pesticide use,” primarily on private lands and designated open spaces managed by public
agencies, not the federal government.29 Turtles rely on wetlands as well as “upland areas that are
crucial for reproduction [and] are frequently not protected.” Due in large part to the loss of once
vast wetlands in the Columbia and Willamette River basins, “declines in abundance of turtles in
the Willamette Basin and Columbia Basin must have been great.”30 The agencies found that
among the threats to Western painted turtle are contaminants:
Broad-scale pesticide use to reduce mosquito larvae in wetland areas may reduce
invertebrate prey. The largest wetlands are most likely to undergo pesticide use to
reduce mosquito larvae and it is these wetlands that contain the largest remaining
painted turtle populations in the Portland metropolitan region. In one wetland
complex, larvicide was applied more than ten times to the wetlands’ perimeter
during a single spring-summer season (E. Stewart, pers. obs.). Effects of repeated
applications on non-target dipteran populations and wetland food webs are poorly
understood. In addition, herbicide use for aquatic invasive plants may alter the
availability of cover and basking sites especially for very small turtles. Other
sources of water pollution may also affect western painted turtles. No information
was found detailing with any of these potential threats.31
29
Id. at 6.
30
Id. at 26.
31
Id. at 36-37.