Download FLORA AND FAUNA IMPACT ASSESSMENT

Fauna Management Plan for Pittwater LGA
May 2011
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APPENDIX 7 KEY THREATENING PROCESSES AND THREAT ABATEMENT PLANS
1.0 Key Threatening Processes (KTPs)
1.1
Exotic Vines and Scramblers
Exotic vines and scramblers have the ability to alter a community by smothering native species and
preventing regeneration, occurring at all strata levels, these impacts then flow on to fauna species.
In Pittwater the Coastal Saltmarsh, Pittwater Spotted Gum, Swamp Oak Floodplain, Swamp
Sclerophyll Forest and Littoral Rainforest EEC’s may be affected by this Key Threatening Process
(KTP).
Specific Management Options include:
• Bush regeneration in remnant bushland.
1.2
Entanglement or Ingestion of Anthropogenic Debris in Marine and Estuarine Environments
This KTP refers to human generated objects polluting the waterways, including fishing gear,
packaging materials, convenience items and raw plastics. These items may be either ingested
accidentally or mistaken for prey items and have been known to cause injuries, death and
poisoning. Foreign items have also been regurgitated for offspring. Threatened species in Pittwater
known to have been affected by this KTP include Diomedea exulans Wandering Albatross,
Macronectes giganteus Southern Giant-petrel, Chelonia mydas Green Turtle, Dermochelys
coriacea Leathery Turtle, Diomedea melanophris Black-browed Albatross, Arctocephalus pusillus
Australian Fur-seal and Megaptera novaeangliae Humpback Whale. Likely to also affect, Sterna
albifrons Little Tern, Dugong dugong Dugong, Charadrius mongolus Lesser Sand-plover,
Haematopus fuliginosus Sooty Oystercatcher, Haematopus longirostris Pied Oystercatcher,
Pandion haliaetus Osprey, Eubalaena australis Southern Right Whale (NSW Office of Environment
and Heritage (formerly DECCW) website – final determination of Key Threatening Process)
Also the following non threatened may be affected Numenius madagascariensis Eastern Curlew,
Numenius phaeopus Whimbrel and Limosa lapponica Bar-tailed Godwit (NSW Office of
Environment and Heritage (formerly DECCW) website – final determination of Key Threatening
Process).
Injury and fatality to vertebrate marine life caused by ingestion of, or entanglement in, harmful
marine debris is also listed as a key threatening process nationally in the EPBC Act.
Specific Management Options include:
• Public education encouraging the responsible disposal of litter.
• Include this topic within education programs conducted by the Coastal Environment Centre
1.3
Removal of Dead Wood and Dead Trees.
This KTP includes the removal of standing dead wood and debris on the ground, usually for ‘tidy
up’ and firewood. Removal of dead wood and dead trees results in loss of biodiversity, as it
reduces availability of hollows and input of material into litter layer and soil. This also then results in
reduced regeneration over time. Microhabitat for invertebrates is also removed, and this fauna
group is an important part of an ecosystem. This KTP will also increase wind and soil erosion and
loss of moisture. Specific threatened species in the Pittwater area that may be affected by this are
Broad-headed Snake, Heath Monitor, Glossy Black-cockatoo, Turquoise Parrot, Barking Owl,
Masked Owl, Spotted-tailed Quoll, Eastern False Pipistrelle, Eastern Freetail Bat, Squirrel Glider
and Red-crowned Toadlet. Removal of dead wood may also encourage other species to become
threatened (e.g. Brown Antechinus and Bush Rat) (NSW Office of Environment and Heritage
(formerly DECCW) website – final determination of Key Threatening Process).
Specific Management Options include:
• Management plans for reserves should include the retention of dead wood and dead trees
where possible.
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1.4
Death or Injury to Marine Species following capture in Shark Control Programs on Ocean
Beaches.
This KTP refers to marine fauna that becomes bycatch in the shark nets that are set between
September and April at swimming beaches. The threatened species in Pittwater that may be
affected by these nets include the Dugong, Australian Fur-seal, Green Turtle, Leathery Turtle and
Humpback Whale. Any deaths caused by these nets have a detrimental affect to the survival of the
species (NSW Office of Environment and Heritage (formerly DECCW) website – final determination
of Key Threatening Process).
The objective of Shark Control Programs is to reduce the number of potentially dangerous sharks
at popular swimming beaches and thereby lower the likelihood of a shark attack. Beach meshing
(nets) and drum lines are set off beaches along the coastline with the purpose of intercepting and
culling sharks that are considered to be a threat to people. Mesh nets do not totally enclose
beaches and therefore do not provide a complete barrier between sharks and people. The Shark
Control Program in New South Wales employs only beach meshing. However beach meshing
(nets) used in Shark Control Programs have resulted in the capture and mortality of many marine
species including some that are listed as threatened (Pittwater Council).
Mesh nets and drum lines capture both target shark species (Whaler Sharks, Tiger Sharks,
Hammerhead Sharks, Mako Sharks, Sevengill Sharks and Thresher Sharks) (NSW Fisheries).
Target shark species are those that are euthanased if caught alive. Non-target marine species that
are caught alive are released (Pittwater Council).
Specific Management Options include:
• Although not a direct responsibility of Council it is very useful to maintain up to date information
for members of the community that may call due to concern regarding injured native marine
species. It is recommended Council continue developing education programs (through the
Coastal Environment Centre) to educate the wider community regarding these species.
• Should an injured or deceased marine mammal or a threatened species be identified near or
on a foreshore within the Pittwater LGA, the first point of contact is the local National Parks &
Wildlife Service as marine mammals and threatened fauna fall under the NSW Office of
Environment and Heritage jurisdiction.
• If the animal is injured, Taronga Zoo may also be contacted as the nearest local specialist
centre with facilities able to hold and/or rehabilitate a number of marine species.
• Simultaneously, the voluntary group Organisation for the Rescue and Rehabilitation of
Cetaceous Animals (ORRCA) is also an appropriate voluntary group that may provide
immediate assistance on the ground e.g. in the case of a stranded or entangled whale.
1.5
Infection of Frogs by Amphibian Chytrid causing the disease Chytridiomycosis
Amphibian chytrid is a global waterborne fungal disease, affecting frog populations by causing
death to the adults. Collection, handling and transportation of infected frogs or material between
habitats may promote disease spread. The disease is known to affect two of the threatened frogs
that occur in Pittwater, the Green and Golden Bell Frog and Red-crowned Toadlet. The threatened
Giant Burrowing Frog may also be at risk along with the currently common species, the Eastern
Banjo Frog and Leaf-green Tree Frog.
Symptoms of the disease include discoloured skin, sloughing or peeling skin, sitting in open rather
than sheltering, sluggish and no appetite, slightly splayed legs to a rigid body with outstretched
back legs in severe cases (NPWS website). Infection of amphibians with chytrid fungus resulting in
chytridiomycosis is also listed as a key threatening process nationally in the EPBC Act.
Specific Management Options include:
• Minimise handling of frogs. If necessary, disposable gloves, sample bags and sterile
equipment should be used (NPWS website).
• All equipment and wet or muddy footwear should be clean and dry before and between visiting
frog sites (NPWS website).
• Frogs should not be moved between sites (NPWS website).
• A suitable authority (e.g. Pittwater Council Environment Officer) should be notified if Chytrid
fungus is suspected.
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•
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1.6
Known sites containing the fungus should be documented by council and information be
supplied to persons using this area.
Include this topic within education programs conducted by the Coastal Environment Centre.
Infection by Psittacine Circoviral (beak and feather) Disease affecting endangered Psittacine
species and populations
Beak and feather disease does not seem to impact greatly on a species unless it is stressed in
other ways, for instance has low population numbers. Threatened species in Pittwater that are
known to contract the disease are the Gang-gang Cockatoo and Swift Parrot. (NSW Office of
Environment and Heritage (formerly DECCW) website – final determination of Key Threatening
Process). Parrots with clinical disease are frequently rescued, and released on recovery, however
it has been found that they remain latently infected with the virus and therefore capable of
increasing the spread of the disease in the wild (Department of the Environment and Heritage,
2005). Psittacine Circoviral (beak and feather) Disease affecting endangered psittacine species is
also listed as a key threatening process nationally in the EPBC Act.
Specific Management Options include:
• Recommend the public not feed birds, as the concentration of animals at a feeding station
increases the risk of spreading the disease.
• Birds that are known to be carrying the disease should not be released back into the wild. Birds
to be rehabilitated and released should not be housed with birds known to have the disease.
• Local wildlife groups should be well informed about the disease and the implications of
releasing parrots carrying the disease.
• Improve the availability of nest hollows by retaining natural hollows as well as nest-boxes to
supplement areas that have been degraded.
• Increase natural food availability by planting feed trees and shrubs.
• Include this topic within education programs conducted by the Coastal Environment Centre.
1.7
Competition from feral Honey Bees
Feral honeybees use tree hollows for hives, resulting in competition for tree hollows with native
fauna species. Hollows are used by at least 20% of bird species, all arboreal marsupials except
Koalas, many microbats and scansorial mammals. Threatened species which are likely to be
affected by competition from honeybees for hollows in the Pittwater area include the Squirrel Glider
and Glossy Black Cockatoo. Populations of protected species that may become threatened include
the Common Brushtail Possum and Sugar Glider. There is also competition for floral resources
between the honeybees and native fauna (mammals, birds and invertebrates). Removal of pollen
by honey bees has been shown to impact on seed set in some plant species, as they require the
natural foragers to successfully pollinate their flowers (NSW Office of Environment and Heritage
(formerly DECCW) website – final determination of Key Threatening Process).
Specific Management Options include:
• Encourage local apiarists to responsibly manage bee hives to reduce swarming.
• Honey bees hives may be removed from significant hollows. However it is likely that this will
only be a temporary measure.
1.8
Importation of Red imported Fire Ants into NSW
Fire Ants are native to South America and occur in large colonies. This ant readily damages plants
and preys on invertebrates and slow moving vertebrates. People, stock and domestic pets are
readily stung of which has been known to cause anaphylactic shock. To date, the Fire Ant has only
been recorded in Queensland (NSW Office of Environment and Heritage (formerly DECCW)
website – final determination of Key Threatening Process). The reduction in the biodiversity of
Australian native fauna and flora due to the red imported fire ant, Solenopsis invicta (fire ant) is
also listed as a key threatening process nationally in the EPBC Act.
Specific Management Options include:
• Notify suitable authority if a population of Fire Ants is identified or suspected within the LGA.
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1.9
Infection of Native Plants by Phytophthora cinnamomi
This disease is a soil borne pathogen that moves via surface water flows and spread of growing
roots that come into contact with roots of another plant. It can also be spread by the movement of
soil through human disturbances such as car tyres and boots. This disease was first associated
with plant deaths in the late 1940’s. In Pittwater the threatened Southern Brown Bandicoot may be
affected by loss of habitat as a result of this disease (NSW Office of Environment and Heritage
(formerly DECCW) website – final determination of Key Threatening Process). Dieback caused by
the root-rot fungus (Phytopthora cinnamomi) is also listed nationally as a key threatening process
in the EPBC Act.
Specific Management Options include:
• Management of the disease is limited. Good hygiene, use of chemicals and restricted access
has been used in conservation reserves, but success in controlling the disease has been
limited (Cahill et al., 2008).
1.10
Alteration to Natural Flow Regimes of Rivers, Streams, Floodplains & Wetlands
Altering the natural flow of waterways causes a loss of biodiversity and ecological function in
aquatic ecosystems, as this changes the characteristics of the habitat available to both fauna and
flora species. Flow regimes include a reduced or increased flow, season of flow, frequency,
duration, magnitude and altered water levels. Causes of alterations may include dams, weirs,
diversion, extraction, dredging and floodplain storage. It also changes the habitat available. This
KTP affects waterbird species, frogs and other aquatic fauna (NSW Office of Environment and
Heritage (formerly DECCW) website – final determination of Key Threatening Process).
Specific Management Options include:
• Retain and restore natural flow regimes (including water quality and sedimentation) of
waterways within Pittwater LGA where possible.
1.11
Clearing of Native Vegetation
Clearing of native vegetation is the largest contributor to the loss of biodiversity. In New South
Wales at least 61% of the original native vegetation has been cleared, thinned or substantially or
significantly disturbed between 1788 and 1997. Clearing of native vegetation also results in the
loss of local populations of individual species, fragmentation, expansion of dryland salinity, riparian
zone degradation, increased greenhouse gas emissions, increased habitat for invasive species,
loss of leaf litter layer, loss or disruption of ecological function and changes to soil biota. This KTP
affects all fauna species, but has a greater affect on those already under stress. Land clearance is
also listed as a key threatening process nationally in the EPBC Act.
Specific Management Options include:
• The retention of native vegetation.
• Revegetation of previously cleared areas with locally indigenous plant species.
1.12
Competition and Grazing by the feral European Rabbit
The European Rabbit can be in competition with grazing native animals however none of the
species currently occurring in Pittwater are likely to suffer from this competition. Activities of the
Rabbit can cause degradation of vegetation, as well as erosion and loss of topsoil by wind and
rain. Therefore some fauna in Pittwater may be secondarily affected by rabbits due to habitat
degradation. Feral rabbits can also maintain populations of feral predators such as cats and foxes
at high levels, becoming a problem if the rabbit population drops, causing the feral predators to
move onto native fauna (NSW Office of Environment and Heritage (formerly DECCW) website –
final determination of Key Threatening Process). The Southern Brown Bandicoot is the most likely
threatened species to be affected by the rabbit in Pittwater. Competition and land degradation by
rabbits is also listed nationally as a key threatening process in the EPBC Act.
Specific Management Options include:
• Employ suitable pest control measures to reduce the rabbit population.
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1.13
Human-caused Climate Change
Human-caused climate change results in changes to the average weather conditions as well as a
higher frequency of extreme weather events. Climate change will disadvantage those species that
are too slow or unable to adapt to the change. Fragmentation will make it difficult for species to
migrate to suitable conditions (NSW Office of Environment and Heritage (formerly DECCW)
website – final determination of Key Threatening Process). Loss of terrestrial climatic habitat
caused by anthropogenic emissions of greenhouse gases is also listed as a key threatening
process nationally in the EPBC Act.
Specific Management Options include:
• Educate and encourage the population of Pittwater to conserve energy and fuel.
1.14
Predation by feral Cats
Feral cats eat mammals (usually < 220g), birds, reptiles, amphibians, invertebrates and carrion.
Threatened species in Pittwater that can be impacted by this KTP include the Little Tern, Southern
Brown Bandicoot, Eastern Pygmy-possum, Squirrel Glider, the threatened microbats (table 1) and
frogs (table 1). Many other small mammals, birds and reptiles are taken by cats (NSW Office of
Environment and Heritage (formerly DECCW) website – final determination of Key Threatening
Process). Predation by feral cats is also listed as a key threatening process nationally in the EPBC
Act.
Although this KTP is referring to feral cats, domestic cats are also known to forage on a wide range
of native fauna. Further discussion on the impact of cats is discussed in Section 6.7.
Specific Management Options include:
• Employ suitable pest control measures to reduce the feral cat population.
• Refer to section 6.7.
1.15
Predation by the Red Fox
The fox is an adaptable and elusive predator common in rural, urban and bushland areas
throughout southern Australia. It does not appear to favour any particular habitat and the main
determinants of its population size and distribution appear to be food supply, disturbance of natural
habitats and availability of refuges. The fox is predominantly carnivorous and is largely
opportunistic in its selection of prey.
Medium-sized terrestrial mammals and birds that feed, roost or nest on the ground are particularly
vulnerable (paragraph taken from Smith and Smith, 2000).
In the Pittwater area, fox predation is a concern for many species of threatened fauna including the
Little Tern, Squirrel Glider, Koala, Bush Stone-curlew, Southern Brown Bandicoot, Eastern Pygmypossum, Giant Burrowing Frog, Red-crowned Toadlet, Rosenberg’s Goanna, Australasian Bittern
and Black Bittern.
Predation by European red fox is also listed as a key threatening process nationally in the EPBC
Act.
Specific Management Options include:
• A suitable pest control program to reduce the Red Fox population in Pittwater, concentrating on
known problem areas and reserves. It may be possible to eradicate the species from
Barrenjoey Peninsula, however unlikely to achieve in the remainder of Pittwater LGA.
1.16
Bushrock Removal
Bushrock removal is defined as the removal of natural surface deposits of rock from rock outcrops
or from areas of native vegetation. The rocks may be loose rocks on rock or soil surfaces, or
removal may involve excavation or blasting. Bushrock removal removes or disturbs the habitat of
native fauna species that shelter in or under rocks, or use rocks for basking, and native flora
species that grow in rocky areas (paragraph taken from Smith and Smith, 2000).
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In the Pittwater area, Bushrock Removal is a concern for a number of fauna species including the
threatened Red-crowned Toadlet, Spotted-tailed Quoll, Large-eared Pied Bat, Eastern Cave Bat
and Broad-headed Snake.
Specific Management Options include:
• Restrict bushrock removal from any areas of bushland
1.17
Ecological consequence of High Frequency Fires
High frequency fire is defined as two or more successive fires close enough together in time to
interfere with or limit the ability of plants or animals to recruit new individuals into a population, or
for plants to build up a seed bank sufficient in size to maintain the population through the next fire
(Smith and Smith, 2000).
The impact of inappropriate fire regimes is discussed in section 6.5.
Threatened species known from the Pittwater area that are likely to be greatly impacted by this
KTP include the Glossy Black-Cockatoo, Spotted-tailed Quoll, Southern Brown Bandicoot and
Squirrel Glider.
Specific Management Options include:
• Pittwater Council and local Bush Fire Management authorities need to consider the effect of
high frequency fires on local fauna, particularly threatened species when preparing and
implementing fire management plans.
1.18
Predation by the Plague Minnow (Gambusia holbrooki)
The Plague Minnow is a small freshwater fish that was imported from North America in the 1920’s
as an aquarium fish and subsequently released into creeks around Sydney, Melbourne and
Brisbane in an unsuccessful attempt to control mosquito populations. They are aggressive and
voracious predators that have become so abundant in some areas that they are now a serious pest
(paragraph taken from Smith and Smith, 2000).
Plague Minnows are known predators on the eggs and tadpoles of the endangered Green and
Golden Bell Frog (Litoria aurea), and it has been suggested that this predatory behaviour has been
a major factor in the decline of this frog species (Morgan and Buttemer 1996). Other threatened
species that may be potentially affected by this KTP are the Giant Burrowing Frog and Redcrowned Toadlet. In Pittwater, Plague Minnows are known to occur at Irrawong Reserve (Pittwater
Council 1996) and Warriewood Wetlands (Shortland Wetlands Centre 1989), and are likely to be
widespread and abundant in other creeklines and freshwater bodies (Smith and Smith, 2000).
Specific Management Options include:
• Identify locations in Pittwater where Plague Minnows pose a threat to Giant Burrowing Frog,
Red-crowned Toadlet and Green and Golden Bell Frog populations.
• Develop and implement control programs to eradicate the species at these locations.
1.19
Invasion of native plant communities by Bitou Bush and Boneseed
Bitou Bush and Boneseed are introduced bushes from South Africa. They were planted extensively
for dune stabilisation and spread rapidly invading and displacing native plant communities (NSW
Office of Environment and Heritage (formerly DECCW) website- final determination of key
threatening process). The alteration of natural habitat may impact on fauna inhabiting coastal
dunes.
Specific Management Options include:
• Develop and continue with natural revegetation programs in dune areas.
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1.20
Lantana (Lantana camara)
Introduced from central and tropical South America in the mid 1800’s, Lantana camara has
vigorously spread along the east coast of Australia (NSW Office of Environment and Heritage
(formerly DECCW) website- final determination of key threatening process). This species is able to
invade and dominate the understorey, particularly in areas that have been disturbed, suppressing
native flora species. This then alters the habitat available for fauna species.
Specific Management Options include:
• Bush regeneration projects should aim to control Lantana camara and reduce its abundance
where possible.
1.21
Loss of Hollow-bearing Trees
Hollows are lost as a result of land clearance, removal of dead trees, removal of dead / damaged
limbs, removal of individual trees, logging and a reduced regeneration of large old trees. Generally
trees need to be large and old before developing hollows. For example blackbutt hollows don’t
usually form until the tree is over 200 years (Rhodes, 2001). Hollow production also depends on
death rot, fire and insect attack (Rhodes, 2001).
In NSW, at least 46 mammals, 85 birds, 32 reptiles and 16 frogs are reliant on tree hollows for
shelter and nests. Of these, 45 species are listed as threatened on the TSC Act (NSW Office of
Environment and Heritage (formerly DECCW) website- final determination of key threatening
process). Hollow dependent threatened species known to occur in Pittwater include the Gang-gang
Cockatoo, Glossy Black-cockatoo, Barking Owl, Powerful Owl, Sooty Owl, Eastern Pygmy-possum,
Spotted-tailed Quoll, Eastern False Pipistrelle, Eastern Freetail Bat, Squirrel Glider, Greater Broadnosed Bat and Broad-headed Snake.
Specific Management Options include:
• Encourage the retention of hollows and trees that are likely to contain hollows in the future.
• Educate the community about the importance of hollow-bearing trees.
• Include this topic within education programs conducted by the Coastal Environment Centre.
• Encourage the use of appropriate nest boxes throughout the wider community.
1.22
Forest Eucalypt Dieback associated with Over-abundant Psyllids and Bell Miners
This key threatening process refers to the tree canopy dieback, associated with the over-abundant
populations of psyllid insects, often with over-abundant bell miners Manorina melanophrys. It is not
known whether these organisms are the primary cause of the dieback or whether they are
secondary and tertiary contributors. If defoliation persists over a long period of time, the result may
be tree death and eventually loss of forest structure and fauna habitat (NSW Office of Environment
and Heritage (formerly DECCW) website – final determinations - key threatening process).
Disturbed areas, with fragmentation, logging, nutrient enrichment, altered fire regime and weed
invasion have increased susceptibility to this KTP. Often areas affected have high soil moisture, a
reduced tree canopy cover and a dense understorey (e.g. Lantana).
Specific Management Options include:
• This KTP is difficult to manage. Improving the quality of bushland in Pittwater, thereby
improving the health of the ecological communities and increasing resistance to the dieback
may help.
1.23
Predation and Hybridisation by feral Dogs (Canis lupus familiaris)
Domestic dogs became feral in Australia shortly after the arrival of Europeans. Low numbers of
Dingos occurred throughout mainland Australia at that time. Conditions present at that time did not
allow Dingo numbers to increase. Modification of habitat and increased prey availability, as well as
a continual influx of domestic dogs in the wild has allowed the numbers of feral dogs to increase.
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There is evidence that the Dingo played an important role in natural ecosystems, however the feral
dogs and hybrids appear to be posing a threat to native fauna prey species, due to their greater
abundance, having up to 2 litters annually and differing hunting behaviour, social structure and
body size (NSW Office of Environment and Heritage (formerly DECCW) website – final
determinations - key threatening process).
Specific Management Options include:
• Encourage residents to be responsible dog owners and keep their pets confined. See section
6.7 for more information.
1.24
Loss and/or Degradation of Sites used for Hill-topping by Butterflies
Hill-topping in butterflies is a very complex behaviour that often facilitates meeting of the sexes.
Hill-tops act as a focus for mating. Many butterfly species, especially in the families Hesperiidae,
Papilionidae and Lycaenidae appear to be obligatory hill-toppers and tend to congregate on hill or
ridge tops that are usually higher than the surrounding countryside. The nature of the sites varies
and a site may be as small as a few square metres or may cover several hectares, or display minor
or very marked topographic relief. The same sites are used year after year, whilst apparently
similar nearby sites may not be used. Sites do not necessarily provide nectar food sources for the
butterflies or food plants for the next generation of caterpillars. Hill-top aggregations are essential
for continuity of the reproductive cycle of some butterfly species, and hill-top sites may constitute
vital focal points for such aggregations. The importance of hill-topping sites is out of proportion to
their extent, so that a small area can be vital to the survival of species over a larger area.
Hill-topping butterflies are almost entirely males that frequently take flights over the area. These
flights follow a more or less set pattern, with 'patrolling' males investigating females that enter the
area. Most of the females that fly to the hilltop are virgin. These females soon mate, and after
mating leave the site to seek appropriate food plants, which may be several kilometres distant on
which to lay their eggs.
Hill-top physiognomy is important to hill-topping butterfly species. Small changes in the appearance
of a site can result in males not recognising it as a suitable site. Factors which determine whether
a site is used or not can be quite subtle so that changes causing butterflies to abandon a site can
be quite small. Disturbance of plants on, or topography of, the hill-top, or to its slopes and
immediate surroundings, may render it unsuitable to butterflies as a hill-topping site. In the absence
of other hill-topping sites, butterflies may disappear entirely from a district.
1.25
Invasion of Native Plant Communities by Exotic Perennial Grasses
A number of exotic perennial grasses including Cenchrus ciliaris (Buffel Grass), Hyparrhenia hirta
(Coolatai Grass), Eragrostis curvula (African Lovegrass), Nassella neesiana (Chilean Needlegrass)
and Nassella trichotoma (Serrated Tussock) invade and may dominate native plant communities
competing with, and displacing, many native species. Some other perennial grasses that invade
smaller areas of native plant communities include Agrostis capillaris (Browntop Bent), Andropogon
virginicus (Whisky Grass), Chloris gayana (Rhodes Grass), Cortaderia spp. (Pampas Grasses),
Ehrharta erecta (Panic Veldgrass), Melinis minutiflora (Molasses Grass), Panicum repens (Torpedo
Grass), Paspalum urvillei (Vasey Grass), Pennisetum clandestinum (Kikuyu), Phalaris aquatica
(Phalaris), Setaria sphacelata (South African Pigeon Grass), Sporobolus fertilis (Giant Parramatta
Grass), Sporobolus natalensis (Giant Rats Tail Grass) and Urochloa mutica (Para Grass). Other
exotic perennial grasses not specified may, or have the potential to, adversely affect native plant
communities and native species.
The characteristics of vigorous growth, prolific seed production and effective seed dispersal enable
many exotic perennial grasses to compete strongly with, or in some places displace, native
vegetation. Exotic perennial grasses may also change the fuel load in plant communities. The
changed structure and fire regime of the habitat is likely to adversely impact on both native
vertebrate and invertebrate fauna.
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Dense monocultures of perennial grasses that develop after invasion threaten local vegetation at
all sites that are affected. This may result in local and regional declines of many native species and
communities, possibly to the extent that they become endangered. Many of the perennial exotic
grasses establish following disturbances such as overgrazing, road works and management of
roadside areas. Spread of these grasses is often aided by slashing, weed control, forestry and
mining operations, movement or addition of fertilisers and nutrients, changes to drainage and fire
regimes.
Specific Management Options include:
• Bush regeneration projects should aim to control these weeds and reduce their abundance
where possible.
• Encourage the use of local native plants in landscaping.
1.26
Competition and Habitat Degradation by feral Goats
Feral Goats are distinguished from domestic goats by not being permanently restrained by fences
or subject to husbandry. Feral Goats are versatile generalist herbivores. They will browse shrubs
and trees, graze forbs and grass, and eat fallen fruit capsules, bark and other dead plant material.
Feral Goats appear to have a high taste threshold for compounds in many trees and shrubs
normally unpalatable to other herbivores and can survive on fibrous herbage with low levels of
nutrients. Feral Goats have a high reproductive potential. In the absence of control, Feral Goat
populations can increase by up to 75% per year.
Feral Goats present a potential threat to plant communities given the large number of plant species
that are palatable to them and their ability to browse and graze in inaccessible areas such as in
trees or in dense thickets. Further, the ability of Feral Goats to survive on low nutrient fibrous
vegetation enables them to continue to feed under adverse environmental conditions.
Feral Goats can cause significant habitat degradation. Removal or destruction of vegetation
together with trampling by ungulate herbivores decreases soil stability and contributes to erosion.
It is unlikely this activity occurs in Pittwater.
1.27
Introduction of Large Earth Bumblebee (Bombus terrestris)
The Large Earth Bumblebee, Bombus terrestris (L.) (Hymenoptera: Apidae), is a relatively large,
primitively eusocial bee native to Europe. Bombus terrestris is generally more heavily built and
hairier than the honeybee, Apis mellifera L.
At present this species is not known to occur in NSW, but could establish through accidental
introduction from colonies in Tasmania or New Zealand, or deliberate introduction as a pollinating
agent.
Large Earth Bumblebees are specialist pollinators of a number of European plant species, either
because they require a bee of a certain size (e.g. foxglove, Digitalis spp.), weight (e.g. Scotch
Broom, Cytisus scoparius), or require buzz pollination to release pollen from poricidal anthers (e.g.
many Solanaceae). This may facilitate an increase in the abundance and distribution of weed
species. The presence of the Large Earth Bumblebee may also disrupt pollination of native plant
species (Hingston and McQuillan 1998).
1.28
Herbivory and Environmental Degradation caused by Feral Deer
Six species of deer (family Cervidae) have established feral populations in New South Wales. All
species extant in NSW have patchy distributions in forest and woodland in eastern New South
Wales, with two species (Red and Fallow Deer) extending west of the Great Dividing Range.
Recent reports indicate that the distributions and abundances of all species of deer have increased
in NSW between 1979 and 2001. Although they are large mammals, deer are cryptic and there are
no state-wide censuses of numbers. Bioclimatic modelling suggests that all species could increase
their distributional ranges further in NSW.
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The five species of feral deer currently established in NSW are primarily grazers, but all species
browse opportunistically on the buds, shoots and leaves of trees and shrubs. Deer may also strip
bark from woody plants and browse on reproductive structures. All deer species are classed as
'intermediate mixed grazers' indicating that they can feed on a combination of shrub, understorey
and grass species depending on availability.
Impacts of feral deer on indigenous biota in Australia have been poorly studied. However,
documented impacts of feral deer in conservation reserves include overgrazing, browsing,
trampling, ring-barking, antler rubbing, dispersal of weeds, creation of trails, concentration of
nutrients, exposing soils to erosion/accelerating erosion, and the subsequent degradation of water
quality in creek and river systems.
Grazing and trampling by deer could alter the composition and structure of the following
Endangered Ecological Communities: - Littoral Rainforest, O'Hares Creek Shale Forest, Sydney
Freshwater Wetlands, Montane Peatlands and Swamps, River-Flat Eucalypt Forest on Coastal
Floodplains and Swamp Sclerophyll Forest on Coastal Floodplains.
Competition for food may occur between feral deer and macropods, but has been little studied.
Rusa Deer in Royal National Park show a 13% overlap in diet with the Swamp Wallaby Wallabia
bicolor in summer and a 54% overlap in diet in winter.
This activity does not occur in the Pittwater LGA.
1.29
Invasion of the Yellow Crazy Ant
The Yellow Crazy Ant Anoplolepis gracilipes (Hymenoptera: Formicidae), is notable for its frenetic
activity when disturbed (hence its common name) and its long legs and antennae. The Yellow
Crazy Ant is polygynous (multi-queened) and there is no intraspecific aggression among workers. It
can form diffuse supercolonies, sometimes extending continuously over large areas (up to 750 ha).
Single nests of A. gracilipes can contain upwards of 1 000 queens and tens of thousands of
workers. The life cycle of A. gracilipes has been estimated to take 76-84 days.
The Yellow Crazy Ant is a scavenging predator with a broad diet. It preys on a variety of litter and
canopy fauna, from small isopods, myriapods, earthworms, molluscs, arachnids, and insects, to
large land crabs, birds, mammals, and reptiles. In addition to these protein-rich foods, Yellow
Crazy Ants obtain carbohydrates and amino acids from plant nectaries and honeydew excreted by
aphids and scale insects (Homoptera), which are tended on stems and leaves of a wide variety of
tree and shrub species. It is capable of invading both disturbed and undisturbed tropical and
subtropical habitats, including urban areas, rural villages, plantations, coastal strand, grassland,
savannah, woodland, and rainforest.
The Yellow Crazy Ant poses a significant threat to biodiversity as the ants have the potential to
displace native fauna. The Yellow Crazy Ant is known to kill invertebrates, reptiles, hatchling birds
and small mammals. Species and populations in NSW that may become threatened by the
presence the Yellow Crazy Ant include ants such as Rhytidoponera spp., Pheidole spp.,
Paratrechina spp., Eastern Sedgefrog Litoria fallax, Eastern Grass Skink Lampropholis delicata,
and a burrowing skink Ophioscincus truncates. A range of other ground-dwelling invertebrates and
vertebrates may be affected in NSW. In view of the above the Scientific Committee is of the
opinion that Invasion of the Yellow Crazy Ant Anoplolepis gracilipes (Fr. Smith) into NSW could
cause species, populations or ecological communities that are not threatened to become
threatened.
The Yellow Crazy Ant has not been detected within Pittwater LGA.
1.30
Cane Toad (Bufo marinus)
The Cane Toad Bufo marinus L. is a large, squat member of the 'true toad' family, Bufonidae. The
dorsal skin is very warty, with a greatly enlarged pair of parotoid glands behind the eardrum. When
the toad is handled or bitten, these glands exude a milky fluid that contains numerous types of
toxins, which primarily affect the heart (Queensland Museum 2000). Tadpoles, which are black and
up to 27 mm in total length, are also poisonous to predators.
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Cane Toads are capable of exploiting a wide variety of habitats from moist forest to beach dunes,
and are often found in gardens and along roads. Dense vegetation tends to act as a barrier to
movement (DEH 2005). Cane Toads have a catholic diet, with almost any vertebrate or
invertebrate that can be swallowed being vulnerable to predation. Terrestrial arthropods provide
the bulk of the diet. The tadpoles of this species sometimes feed on smaller tadpoles of their own
and other species.
In NSW Cane Toads currently exist in a patchy distribution extending from the Queensland border
south to Broadwater and west to Lismore and the headwaters of Richmond River Valley. Isolated
populations occur at Yamba and Port Macquarie.
The current rate of spread in NSW is approximately 3-4 km per year, but may be punctuated by
brief periods of relatively rapid movement in some years (DEC 2005 in lit.). Modelling of the
potential distribution of Cane Toads in NSW predicts range extensions into north-western slopes of
the Great Dividing Range and throughout coastal areas, with potential expansion into Victoria.
Cane Toad populations can reach very high densities (e.g. 2000 individuals per hectare), and there
is currently no efficient method for significantly reducing established populations. Trapping has
some potential to eradicate small populations or create a barrier to expansion, but is labourintensive. The potential for biological control has been investigated, but is not promising due to the
lack of specificity among control agents available (DEH 2005).
In addition, Cane Toads are likely to cause declines in faunal biodiversity by competing for food
with other carnivores, by preying upon small vertebrates (such as skinks) and by causing
intoxication among larger predators such as goannas (Varanus spp.) and raptors.
To date, only two Cane Toads have been sighted in Pittwater (2009), both in the Newport area. It
is thought these animals may have been arrived via deliveries of soil or mulch. Both animals were
humanely destroyed.
Specific Management Options include:
• Educate the wider community regarding cane toads and encourage residents to report any
sightings to Council.
• Make information available to the public via Council’s website and education programs through
the Coastal Environment Centre.
1.31
Invasion and Establishment of Scotch Broom (Cytisus scoparius)
Scotch Broom, Cytisus scoparius (L.) Link (Fabaceae), is a leguminous shrub native to Europe,
first introduced to Australia in the early 1800s. Subsequent introductions were made for ornamental
purposes and by 1901 it had spread significantly and was declared a noxious weed in NSW
(NPWS 2005).
C. scoparius is estimated to infest more than 200 000 ha in south-eastern Australia and has
become an environmental weed in higher rainfall areas (Hosking et al. 2000). It grows most
successfully in cool temperate areas on moist, fertile soils (Victorian Department of Resources and
Environment 2002). It is continuing to spread through both expansion of existing infestations and
colonization into new areas (Smith 2000). In some locations it has formed near monocultures
(Downey 2002). C. scoparius competes strongly with native vegetation, reducing recruitment of
seedlings and growth of understorey species in open forest areas (Fogarty and Facelli 1999,
Downey 2000, Sheppard et al. 2002, Odom et al. 2003).
Current control options include herbicide application, manual removal and biological control. Three
biological control agents have been released: Leucoptera spartifoliella (a twig-mining moth),
Arytainilla spartiophila (a broom psyllid) and Bruchidius villosus (a seed-eating beetle). A further
two are currently being investigated: Aceria genistae (a gall-forming mite) and Apion fuscirostre (a
seed-eating beetle) (P. Downey pers. comm.). The release program is in an early stage and its
impacts have thus far been limited. A rust, Uromyces pisi-sativi, is now also present throughout the
range of C. scoparius in Australia. Its presence was first noted in 2003 but its impact is uncertain
(Morin et al. 2006).
At this stage, Scotch Broom is not an issue within the Pittwater LGA.
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1.32
Alteration to Habitat following Subsidence due to Longwall Mining
This key threatening process is not relevant to the Pittwater LGA.
1.33
Predation, Habitat Degradation, Competition and Disease Transmission by feral Pigs (Sus
scrofa)
Feral Pigs are found across continental Australia with the highest densities in NSW, Qld and
through northern Australia to the Kimberley region. In 2002, Feral Pigs were estimated to inhabit
61% of the area of NSW and the ACT. 'Predation, habitat degradation, competition and disease
transmission by Feral Pigs' is currently listed as a key threatening process under the
Commonwealth Environment Protection and Biodiversity Conservation Act 1999.
Feral Pigs are opportunistic omnivores. They feed predominantly on grasses, however, bulbs,
tubers, roots, seeds, fruit, fungal fruit-bodies (sporocarps), carrion, and vertebrate and invertebrate
prey are all consumed when available. Feral Pigs have a high reproductive potential with females
capable of producing two litters of up to six piglets every 12-15 months.
Feral Pigs present a significant threat to native species and ecological communities as a result of
their behaviour and feeding habits. Feral Pig wallowing and rooting causes direct disturbance to
habitats and may increase erosion and reduce water quality in streams and pools (Department of
Environment and Heritage (DEH) 2003a).
Feral Pigs are active predators of native birds, reptiles, (including their eggs), frogs and soil
invertebrates such as earthworms as well as the underground storage organs of plants and the
fruiting bodies of fungi.
Feral Pigs have been implicated as potential vectors of disease. In particular, Feral Pigs may be
responsible for spreading Phytophthora cinnamoni, a root-rot fungus responsible for die-back in
native vegetation (DEH 2003b). There is evidence that Feral Pigs can carry the fungus on their
hooves and that the spread of the fungus is associated with soil disturbance and reduction of litter
cover by pigs. Further, chewing and other damage to tree trunks may facilitate infection of
vegetation by the fungus and other diseases.
This key threatening process is not relevant to the Pittwater LGA.
1.34
Invasion of Native Plant Communities by African Olive (Olea europaea)
African Olive, Olea europaea L. subsp. cuspidata, is a small evergreen dense crowned shrub or
tree with a centre of natural distribution in eastern Africa. African Olive was introduced into
th
Australia from southern Africa in the mid 19 century for horticultural purposes and is now well
established as a woody invasive plant in the Cumberland Plain (western Sydney) and Hunter
Valley regions of New South Wales.
African Olive is a highly persistent and long lived tree (100 years or more) which fundamentally
alters ecosystem structure through the formation of a dense mid-canopy in native vegetation
communities. The dense canopy structure (>80% crown cover) of African Olive creates deep
shade at the ground level, preventing the growth of native grasses and herbs.
African Olive produces large crops of small black fruits (>25,000 fruits/tree/year) which are readily
consumed and dispersed by a range of native and introduced birds. Seedlings establish as 'halos'
around large perch trees. Dense seedling 'mats' form in the seed fall zone of mature plants, with
densities of up to 950 seedlings/m2 recorded. African Olive seedlings are able to remain at this
'seedling bank' stage for many years. The dense and persistent canopy of African Olive also
results in long term loss of native species from the soil seedbank, limiting the ability of native plant
communities to naturally regenerate following the long term (>15 years) presence of African Olive.
African Olive is adapted to a wide range of environments from dry exposed ridgelines through to
saline watercourses. African Olive has a clear distributional preference for shale derived clay soils,
and does not readily establish on low fertility sandstone soils.
African Olive does not pose a threat in the Pittwater LGA.
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1.35
Incidental Catch (or bycatch) of Seabirds during Oceanic Longline Fishing Operations
(listed in the EPBC Act only)
It is unlikely that this activity occurs within the Pittwater LGA, however injured seabirds may get
washed into shore along the coastline.
Specific Management Options include:
• Injured seabirds that are listed under the Threatened Species Act such as the Little Fairy
Penguin are rehabilitated by Taronga Zoo in conjunction with NPWS. (These organisations
have an ongoing monitoring program related to the Lion Island and Spring Cove Fairy Penguin
populations).
• A local wildlife group such as Sydney Wildlife or WIRES can be contacted to organise the
rescue and transportation of this species to this facility.
• All other seabirds can be rescued and rehabilitated by local wildlife groups e.g. Shearwaters,
Pelicans and so on.
• Educating the community regarding this process may assist Council when contacted by a
member of the public concerned about an injured animal.
2.0
Threat Abatement Plans (TAPs)
The NSW Office of Environment and Heritage (formerly DECCW) are endeavouring to write threat
abatement plans for all listed Key Threatening Processes as part of the Threatened Species
Conservation (TSC) Act 1995. Currently, final threat abatement plans have been written for the
following Key Threatening Processes:
•
•
predation by the Plague Minnow
predation by the Red Fox
These threat abatement plans may be found at
http://www.environment.nsw.gov.au/threatenedspecies/ThreatAbatementPlans.htm
The Department of the Environment, Water, Heritage and the Arts (DEWHA), have prepared the
following threat abatement plans for nationally listed key threatening processes (only the plans
potentially relevant to Pittwater LGA have been included).
•
•
•
•
•
•
•
•
•
3.0
beak and feather disease affecting endangered psittacine species – 2005
competition and land degradation by rabbits – 2008
dieback caused by the root-rot fungus Phytophthora cinnamomi – 2001
infection of amphibians with chytrid fungus resulting in chytridiomycosis – 2006
predation by European red fox – 2008
predation by feral cats – 2008
impacts of marine debris on vertebrate marine life – 2009
incidental catch (or bycatch) of seabirds during oceanic longline fishing operations - 2006
impacts of tramp ants on biodiversity in Australia and its territories - 2006
NSW Priority Action Statements (PASs)
The NSW Office of Environment and Heritage (formerly DECCW) prepared the NSW Priorities
Action Statement in 2007, which covers broad strategies and detailed priority actions to promote
the recovery of threatened species, population and ecological communities and manage key
threatening processes. Details may be found at the following website.
http://www.threatenedspecies.environment.nsw.gov.au/tsprofile/home_PAS_new.aspx
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4.0
Threatened Species Recovery Plans
The Threatened Species Conservation Act requires the NSW Office of Environment and Heritage
(formerly DECCW) to prepare and implement recovery plans for species, populations and
communities of threatened fauna and flora listed in the Act. Recovery plans for endangered
species, populations and communities are to be prepared as soon as practicable after listing, while
recovery plans for vulnerable species are a longer term objective (Smith and Smith, 2000).
The Act requires local councils and other public authorities to take any appropriate action available
to them to implement those measures included in a recovery plan for which they are responsible.
They must not make decisions that are inconsistent with the provisions of a recovery plan. A
council identified in a recovery plan as responsible for the implementation of measures included in
the plan must report in its annual State of the Environment Report on the action taken by it to
implement those measures (Smith and Smith, 2000).
At present (May 2010), Recovery Plans have been written for the following threatened fauna
species that have previously been recorded in Pittwater:
•
•
•
•
•
•
•
•
•
Bush Stone-curlew
Gould’s Petrel
Little Tern
Southern Brown Bandicoot
Large Forest Owls
Green and Golden Bell Frog (draft only)
Barking Owl (draft only)
Koala
Grey-headed Flying-fox (draft only)
These recovery plans may be found at
http://www.nationalparks.nsw.gov.au/npws.nsf/content/recovery+plans
The Department of the Environment, Water, Heritage and the Arts has prepared recovery plans for
the following threatened species and these may be viewed on their website.
•
•
•
•
•
•
•
Regent Honeyeater
Swift Parrot
Southern Right whale
Green turtle
Shy albatross
Wandering albatross
Black-browed albatross
DEWHA have also prepared a draft document ‘Significant Impact Guidelines for 36 Migratory
Shorebird Species, November 2009’.
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