Platypus graphic

Survival of vertebrate species


of terrestrial vertebrate species are not listed as being threatened

Kangaroo graphic

Mammal range contractions


of native mammals have experienced long term declines in range   

The overall diversity and richness of native species and communities in NSW remains under threat of further decline. The conservation status of 64% of land-based vertebrate species is currently not threatened.

A general pattern of long-term decline in biodiversity is evident in reductions to the range or abundance of many native vertebrate species. At the same time, many species less susceptible to current pressures have maintained their distributions, while a small number of adaptable species have flourished.

Over the past 200 years birds have been more resistant to declines in range than mammals, which have experienced substantial declines, especially small- to medium-sized ground-dwelling species. However, over recent decades there is evidence that populations of some bird groups are declining.

The decline in native species is due to the cumulative impact of many diverse pressures and threats. The main threats are vegetation clearing and habitat degradation and invasive species, with vertebrate fauna, in particular, being impacted by foxes and cats on the mainland and introduced rodents affecting species survival on islands. Climate change is likely to be a major threat to the future survival of many species.

The NSW Government has streamlined and integrated legislation for biodiversity conservation and protection.

The main measures to address the decline in biodiversity are conservation of native species in the public reserve system, the Biodiversity Conservation Trust which funds landowners to manage, protect and conserve biodiversity on private land and through biodiversity offsets, and the Saving our Species program which aims to secure as many threatened species in the wild as possible.

Related Topics: Threatened Species | Invasive Species | Native Vegetation | River Health  

NSW indicators

* You may need to scroll to the right to see the full content, or switch to landscape orientation.

Indicator and status Environmental 
Terrestrial mammals: Loss of distribution - long term (~200 years)
Birds: Loss of distribution - long term (~200 years)
Proportion of vertebrate fauna species that is presently non-threatened
Getting worse ✔✔
Birds: Decline in populations - short term (decades)
Getting worse ✔✔
Large kangaroos: Populations
Stable ✔✔✔
Native fish communities
Getting better ✔✔✔


Terms and symbols used above are defined in How to use this report.


Biodiversity refers to the full range of ecosystems, the species and populations they support and the genes they contain. It also encompasses the complex interactions between living organisms and the environment which provide the basis for a range of ecosystem services and maintain the health and productivity of the land.

NSW has a rich biodiversity, much of which is recognised as being internationally significant.

It is not possible to monitor or report on biodiversity across its breadth (Saunders et al. 1998) because of the limited data available and the sheer amount of biodiversity to be monitored. The vast majority of all species are invertebrates or microorganisms, especially bacteria (Larsen et al. 2017). The focus of this topic is limited to describing the status of native fauna, in particular land-based vertebrate species (mammals, birds, reptiles and amphibians). See the Threatened Species topic for a description of the status and prospects of native plants and animals listed as threatened in NSW.

A shrinking distribution is often the first indication that a species is declining in numbers. Declines in many species have been underway for decades or longer but have largely gone unrecorded. Over the past three decades, heightened awareness of the plight of native flora and fauna has revealed the extent of many of these declines and the threats that cause them. For example, the eastern quoll once ranged over most of eastern NSW but is now found only in Tasmania. It became extinct locally in NSW before any population estimates had been undertaken. In western NSW, 24 species of mammals became locally extinct between European settlement in 1841 and Federation in 1901 (Morton 1990; Lunney et al. 2000).

Much effort has gone into arresting declines that largely occurred before 1995 when the NSW Government recognised the need to formally protect native species. A focus on the extent of declines in species has the potential to mask recent achievements in stabilising declines and recovering some species.

The status of species under threat varies regionally and across Australia. Some species lost from NSW, such as the pig-footed bandicoot, are extinct throughout Australia, while others, such as the numbat, are still found in other parts of Australia. A number of species no longer exist on the mainland of NSW but survive on predator-free islands. The brush-tailed rock-wallaby is listed under both the Biodiversity Conservation Act 2016 (BC Act) and the Commonwealth Environment Protection and Biodiversity Conservation Act 1999, but is under greater threat in Victoria than NSW. Conversely, the koala is threatened in NSW but not in Victoria, where it is regarded as over-abundant in some areas.


The biodiversity of NSW is subject to an increasing number and range of threats. The Biodiversity Conservation Act 2016 (BC Act) and the Fisheries Management Act 1994 (FM Act) both list the key threatening processes (KTPs) that impact on listed threatened species. At 31 December 2017, there were 46 KTPs listed for NSW - 38 under the BC Act and eight under the FM Act. There is some overlap, with climate change, shark meshing and changes to river flow regimes listed under both Acts in slightly different ways.

Table 12.2 summarises the types of KTPs listed. Over half of them relate to invasive species, with 24 associated with pests and weeds and a further five pertaining to pathogens and diseases. Ten KTPs relate to the clearing and disturbance of native habitat.

Table 12.2: Key threatening processes listed in NSW, 2017

* You may need to scroll to the right to see the full content, or switch to landscape orientation.

Issue Number of KTPs

Invasive species


Habitat change






Climate change


Altered fire regimes







As at 31 December 2017


OEH and DPI data 2017

It should be noted that not all these threats are equivalent in effect and the numbers are not necessarily indicative of the cumulative impact of any type of threat. For example, it is expected that over time climate change will become one of the most significant threats described here.

When a species, population or ecological community is listed as threatened under the BC Act or the FM Act, the main pressures and threats affecting its conservation status are described in the listing. These threats were analysed for all threatened species listed at the time of analysis under the Threatened Species Conservation Act 1995, (the predecessor to the current BC Act), to identify those that have the greatest impact on biodiversity and the environment in NSW (Coutts-Smith & Downey 2006).

The pressures affecting the largest number of threatened species in NSW were the clearing and disturbance of native vegetation (87%), followed by invasive pest and weed species (70%).

Clearing and habitat destruction

The clearing of native vegetation results in the direct loss of species and the destruction of habitat. It is followed by lag effects due to disturbance from subsequent land uses and the fragmentation of remnant vegetation, which impedes regeneration and the movement of species across the landscape and leads to a loss of genetic diversity (Cogger et al. 2007; Taylor & Dickman 2014).

Invasive species

Invasive species have contributed to the decline of many native species. Pest animals, particularly foxes and cats, are likely to have had the greatest impact on native fauna and are considered to be responsible for the majority of fauna extinctions on mainland NSW (Morton 1990; Dickman 1996a; Dickman 1996b). Black rats have had a similar effect on Lord Howe Island, while carp is now the predominant species in most rivers of the Murray Darling Basin.

Climate change

As many Australian species are adapted to highly variable climates, they are likely to have the capacity to cope with some level of climate change. However, the resilience of many species may have been eroded by existing pressures, which have resulted in the declines in numbers or range described in this topic. Climate change is expected to exacerbate the effects of existing threats and introduce additional pressures (Steffen et al. 2009; DECCW 2010a; Hughes 2011). It is likely that climate change will surpass habitat destruction as the greatest global threat to biodiversity over coming decades (Leadley et al. 2010). For further information see the Climate Change topic.

Other threats

Water extraction and altered river flows and cycles have an impact on the critical ecological processes that trigger breeding in a range of aquatic and bird species (see the River Health topic), while altered fire regimes impact on the ability of plant species and communities to regenerate or repropagate.

Most of the main threats to biodiversity in NSW are described in greater detail in other sections of this report, including:

  • clearing, fragmentation and the disturbance of native vegetation (see Native Vegetation);
  • the introduction and spread of invasive species – pests, weeds, diseases and pathogens (see Invasive Species)
  • overgrazing by cattle, sheep and invasive herbivores (see Native Vegetation)
  • water extraction and changes to river flows (see Water Resources)
  • increasing populations and expanding human settlements (see Population)
  • the increasing impacts of climate change (see Climate Change).

Threats not dealt with specifically in other sections of this report include:

  • altered fire regimes due to European settlement
  • the indirect impacts of development, particularly in new areas where high rates of mortality and injury to wildlife can occur
  • disturbance to behaviour and breeding cycles from infrastructure, noise and lighting (Byron et al. 2014).

It should be noted that many of these threats can operate together to have a cumulative impact and hasten the decline of species and communities. Sometimes these impacts may be synergistic, where the cumulative impact is greater than the sum of the individual pressures (Raffaele et al. 2011; Goldman Martone & Wasson 2008; Simberloff & Von Holle 1999).

It is unrealistic to expect that a full range of biodiversity could ever be monitored systematically with available resources. It is therefore an ongoing challenge to optimise monitoring information so that it informs decision-making for managing biodiversity effectively.

Although knowledge of the conservation status of species has improved markedly over the past 20 years, especially on the distribution and abundance of land-based vertebrates, less is known about other groups. Patterns of decline that are likely to have been present for many years are still being discovered in the less well-studied groups of species. For most invertebrates, microorganisms and many plant groups, which comprise the vast majority of species, information exists for only a few isolated species and this provides little insight into the broader status and management needs of these groups.

The 2014 Independent Biodiversity Legislation Review panel recommended the development of a comprehensive system for monitoring and reporting on the extent and quality of biodiversity in NSW (Byron et al. 2014). Such a system would improve the availability of information to more effectively track the status of all species in NSW. This recommendation was adopted by the NSW Government and new techniques for monitoring biodiversity are under development.


Biodiversity Conservation Act 

Following the Independent Biodiversity Legislation Review, sweeping reforms were made to the legislative framework for land management and biodiversity conservation. Biodiversity legislation in NSW has been consolidated under the Biodiversity Conservation Act 2016 (BC Act), which replaces the Threatened Species Conservation Act 1995 (TSC Act), Nature Conservation Trust Act 2001 and the plant and animal provisions of the National Parks and Wildlife Act 1974. A new rural land management framework was also introduced with the Local Land Services Amendment Act 2016, which replaced the Native Vegetation Act 2003. The laws commenced on 25 August 2017.

Protections for aquatic and marine species remain in the Fisheries Management Act 1994 (FM Act). Amendments to the FM Act are being progressed during 2018 to make this legislation consistent with the BC Act and the Common Assessment Method for national listing of threatened species.

Policy and guidelines for fish habitat conservation and management

In 2013, an updated policy and guidelines were published to maintain and enhance the habitat of native fish species (including threatened species) in the marine, estuarine and freshwater environments (DPI 2013).

Saving our Species program

The Saving our Species program (SoS) aims to maximise the number of threatened species that can be secured in the wild in NSW for 100 years. SoS plays a pivotal role in threatened species conservation, and its systematic and pragmatic approach has been formally adopted in the BC Act. Through SoS, land-based threatened species have been allocated to one of six management streams, depending on their distribution, ecology, security and what is known about them. The six management streams are:

  • Site-­managed species: species that can be successfully secured by targeting conservation projects, such as weeding or revegetation, at specific sites (e.g. the smoky mouse, eastern bristlebird and granite rose)
  • Iconic species: six species that are especially valued by the community – the koala, brush­tailed rock­-wallaby, mallee fowl, plains wanderer, southern corroboree frog and Wollemi pine
  • Data-­deficient species: species where there isn’t sufficient information to allocate them to another management stream (e.g. Sloane's froglet, finger panic grass and the matted bush pea)
  • Landscape-­managed species: species that are distributed across large areas and threatened across the landscape by habitat loss and degradation (e.g. the green-thighed frog, pale­headed snake, yellow­-bellied glider and giant dragonfly)
  • Partnership species: species that are threatened nationally and have important populations in NSW, that will have conservation projects developed to protect them (e.g. the black-striped wallaby and dwarf bush-pea)
  • Keep watch species: species that require no immediate investment because they are either naturally rare, have few critical threats, or are more abundant than previously assumed (e.g. for example Hall's babbler and the spiny mintbush).

Priorities for action under SoS are species in the site-­managed, iconic, data-­deficient and landscape-­managed species management streams. Threatened ecological communities and key threatening processes are also priority actions areas.

In 2016­–17, SoS conservation projects benefited from approximately $23 million in cash and in-­kind contributions from OEH including the Environmental Trust ($16.3 million) and external organisations ($6.7 million). There were 305 active SoS projects across the six management streams, including:

  • six iconic species projects
  • 239 site-­managed species projects
  • nine landscape-­managed species projects
  • one partnership species project
  • 41 data-­deficient species projects
  • two keep watch species projects.

Key actions for these projects include:

  • pest and weed control
  • habitat and site protection and management
  • community and landholder engagement
  • translocation and ex-situ conservation (e.g. captive breeding)
  • research.

Research on data-­deficient species has led to recommendations to move 15 species to a new management stream.

The NSW Government pledged an additional $100 million over five years from 2016–17 to protect the state's threatened species.

Reintroduction of locally extinct mammals

Since 2015, the NSW Government has been working with the Australian Wildlife Conservancy and the University of New South Wales to reintroduce more than 10 species of locally extinct mammals into some public reserves in NSW. The reintroduction of locally extinct mammals is a significant component of the SoS program.

Feral-free fences will protect 180,000 hectares of land from feral predators such as foxes and cats in Sturt National Park, Mallee Cliffs National Park and Pilliga State Conservation Area. Mammals will be reintroduced into these areas following the removal of introduced predators and other pest animals.

In Pilliga State Conservation Area, a 5,900-hectare area of natural habitat will be protected from feral predators and at least six locally extinct mammal species will be reintroduced.

In Mallee Cliffs National Park, an 8,000-hectare area will be protected for at least 10 locally extinct mammal species.

Wildlife licensing

The BC Act established a new risk-based approach to managing wildlife actions through a tiered framework that:

  • permits low-risk activities through Biodiversity Conservation Regulations,
  • allows moderate risk activities under a code of practice,
  • ensures high risk activities will continue to require a licence,
  • provides for actions that have direct impacts on biodiversity, including threatened species, to be treated as offences under the BC Act.

The NSW Government has been consulting with stakeholders to identify which actions should continue to require licensing, and which should be regulated by codes of practice and regulations. This process is ongoing.

Identifying areas of outstanding biodiversity value

The BC Act enables the Minister for the Environment to declare Areas of Outstanding Biodiversity Value (AOBVs). AOBVs are special areas that contain irreplaceable biodiversity values that are important to the whole of NSW, Australia or globally. AOBVs will be a priority for investment in private land conservation.

Existing areas of declared critical habitat under the old TSC Act (Wollemi pine and little penguin habitats) became AOBVs when the BC Act came into effect.

Listing of threatened species and communities

The BC Act modernised the process for listing threatened plants and animals. It aligns threat categories with international best practice and provides greater coordination between Australian jurisdictions. The Biodiversity Conservation Regulations prescribes listing criteria for threatened plants and animals which align with standards developed by the International Union for Conservation of Nature.

The Commonwealth, state and territory governments agreed to establish a common method for assessing and listing threatened species. The process of alignment of assessment and listing under the common assessment method is ongoing. This will reduce duplication of effort among governments by allowing jurisdictions to adopt listing assessments undertaken by other jurisdictions and will lead to better conservation outcomes for Australia's species.

NSW public reserves system

The public reserves system is the cornerstone of conservation efforts in NSW. It plays a vital role in protecting habitat and provides a refuge for many threatened species that are sensitive to habitat disturbance.

The NSW public reserves system covers around 7.14 million hectares or about 9% of the state (see the Protected Areas and Conservation topic). It conserves representative areas of most habitats and ecosystems, and the majority of plant and animal species found in NSW are represented in the public reserve system. Under the new BC Act there is an increased focus on conservation measures on private land to supplement land managed for conservation in the public reserve system.

NSW Koala Strategy

The NSW Government recognises the koala as an iconic threatened species and is committed to stabilising and increasing koala populations across NSW. In May 2018 the government released the NSW Koala Strategy, committing $44.7 million towards securing the future of koalas in the wild. The Strategy will support a range of conservation actions over three years.

The NSW Koala Strategy will deliver:

  • $20 million from the NSW Environmental Trust to purchase and permanently conserve land that contains priority koala habitat in the national park estate
  • $3 million to build a new koala hospital at Port Stephens
  • $3.3 million to fix priority road-kill hotspots across NSW
  • $4.5 million to improve the care of sick or injured koalas
  • $6.9 million to improve our knowledge of koalas, starting with the development of a state-wide koala habitat information base
  • $5 million to deliver local actions to protect koala populations, including through the SoS program
  • $2 million to research impacts of natural hazards and weather events on koalas.

The NSW Koala Strategy responds to the Independent Review into the Decline of Koala Populations in Key Areas of NSW (NSW Chief Scientist and Engineer 2016), which recommended a whole-of-government koala strategy for NSW. An expert advisory committee chaired by the NSW Chief Scientist and Engineer guided the strategy’s development along with extensive community and stakeholder consultation.

Management and control of invasive species

Once established, the eradication of invasive species is seldom feasible. Therefore, control of some high-priority invasive species, such as foxes and bitou bush, is specifically targeted at sites of high conservation value. Control is delivered through threat abatement plans which facilitate whole-of-government coordination across agencies and local authorities.

Broad scale rabbit control is being provided through the release of rabbit haemorrhagic disease, while rats, mice and rabbits have been eradicated from some NSW islands. Local Land Service are responsible for identifying priority weeds regionally and developing programs to manage them (see the Invasive Species topic).

Adaptation to climate change

Priorities for Biodiversity Adaptation to Climate Change (DECCW 2010b) was produced in response to the listing of anthropogenic climate change as a key threatening process under the BC Act. This identifies priority measures for dealing with the effects of climate change over the next five years, focusing on four key areas:

  • enhancing understanding of the likely responses of biodiversity to climate change and readjusting management programs where necessary
  • protecting a diverse range of habitats by building a comprehensive, adequate and representative public reserve system in NSW, with a focus on under-represented bioregions
  • increasing opportunities for species to move across the landscape by working with partners and the community to protect habitat and increase connectivity by consolidating areas of vegetation in good condition
  • assessing adaptation options for ecosystems most at risk from climate change in NSW.

A key threatening processes strategy has been prepared for the SoS program, that includes adaptation processes in response to climate change following the listing of Climate change as a KTP.

The AdaptNSW website provides comprehensive climate change information, analysis and data to support action to address climate change risks and capture opportunities. It includes information on the causes of climate change and the likely impacts on biodiversity. For further information see the Climate Change topic.

Measures to improve connectivity across landscapes and build the health and resilience of the land will enhance the capacity of species and ecosystems to adapt to, and cope with, disturbance.

More information about the factors contributing to the resilience or success of some native species and processes, in contrast to the declines of many others, may assist in efforts to maintain sustainable populations of flora and fauna species.


Birdlife Australia 2015, The State of Australia’s Birds 2015, Birdlife Australia, Melbourne []

Byron N, Craik W, Keniry J & Possingham H 2014, A review of biodiversity legislation in NSW: Final Report, Independent Biodiversity Legislation Review Panel, Office of Environment & Heritage, Sydney []

Cogger H, Dickman C & Ford H 2007, The Impacts of the Approved Clearing of Native Vegetation on Australian Wildlife in New South Wales, WWF-Australia, Sydney

Collen B, Loh J, Whitmee S, McRae L, Amin R & Baillie JE 2009, ‘Monitoring change in vertebrate abundance: the living planet index’, Conservation Biology, 23(2), pp. 317–27, [doi: 10.1111/j.1523-1739.2008.01117.x]

Coutts-Smith AJ & Downey PO 2006, Impact of Weeds on Threatened Biodiversity in New South Wales, Technical Series no. 11, CRC for Australian Weed Management, Adelaide []

DECCW 2009, New South Wales State of the Environment 2009, Department of Environment, Climate Change and Water, Sydney []

DECCW 2010a, NSW Natural Resources Monitoring, Evaluation and Reporting Strategy 2010–2015, Department of Environment, Climate Change and Water, Sydney []

DECCW 2010b, NSW Climate Impact Profile: The impacts of climate change on the biophysical environment of New South Wales, Department of Environment, Climate Change and Water, Sydney []

DECCW 2010c, Priorities for Biodiversity Adaptation to Climate Change, Department of Environment, Climate Change and Water, Sydney []

Dickman CR 1996a, ‘Impact of exotic generalist predators on the native fauna of Australia’, Wildlife Biology, 2(3), pp. 185–95 []

Dickman CR 1996b, Overview of the Impacts of Feral Cats on Australian Native Fauna, Australian Nature Conservation Agency, Canberra []

Dickman CR, Pressey RL, Lim L & Parnaby HE 1993, ‘Mammals of particular conservation concern in the western division of New South Wales’, Biological Conservation, 65(3), pp. 219–48 []

Garnett ST, Szabo JK & Dutson G 2010, The Action Plan for Australian Birds 2010, CSIRO, Melbourne []

Goldman Martone RA & Wasson KB 2008, ‘Impacts and interactions of multiple human perturbations in a California salt marsh', Oecologia, 158(1), pp. 151–63 [­008­1129­4]

Hughes L 2011, ‘Climate change and Australia: key vulnerable regions’, Regional Environmental Change, 11(1) Supplement, pp. S189–95 []

Larsen B, Miller C, Rhodes M & Wiens J 2017, ‘Inordinate Fondness Multiplied and Redistributed: The Number of Species on Earth and the New Pie of Life’, The Quarterly Review of Biology, 92(3), pp. 229–65 [ (PDF 0.7MB)]

Leadley P, Pereira HM, Alkemade R, Fernandez-Manjarrés JF, Proença V, Scharlemann JPW & Walpole MJ 2010, Biodiversity Scenarios: Projections of 21st century change in biodiversity and associated ecosystem services, Technical Series no. 50, Secretariat of the Convention on Biological Diversity, Montreal, Canada []

Lunney D, Curtin AL, Ayers D, Cogger HG, Dickman CR, Maitz W, Law B & Fisher D 2000, ‘The threatened and non-threatened native vertebrate fauna of New South Wales: Status and ecological attributes’, Environmental and Heritage Monograph Series, no. 4, pp. 1–132, NSW National Parks and Wildlife Service, Sydney

MacNally R, Bennett AF, Thomson JR, Radford JQ, Unmack G, Horrocks G & Vesk PA 2009, ‘Collapse of an avifauna: climate change appears to exacerbate habitat loss and degradation’, Diversity and Distributions, 15(4), pp. 720–30 []

Mahon P, King S, O’Brien C, Barclay C, Gleeson P, McIlwee A, Penman S & Schulz M 2011, Assessing the Sustainability of Native Fauna in NSW, Monitoring, Evaluation and Reporting Program, Technical report series, NSW Office of Environment & Heritage, Sydney []

MDBA 2017, 2017 Basin Plan Evaluation: Native Fish, Murray-Darling Basin Authority, Canberra [ (PDF 4.9MB)]

Morton SR 1990, ‘The impact of European settlement on the vertebrate animals of arid Australia: A conceptual model’, in Saunders DA, Hopkins AJM & How RA, Australian Ecosystems: 200 years of utilisation, degradation and reconstruction, Proceedings of a symposium held in Geraldton, Western Australia, 28 August–2 September 1988, Proceedings of the Ecological Society of Australia, 16, pp. 201–13

NSW Chief Scientist and Engineer 2016, Independent Review into the Decline of Koala Populations in Key Areas of NSW, NSW Chief Scientist and Engineer, Sydney [ (PDF 0.5MB)]

OEH 2017, Wildcount: Broad scale, long-term monitoring of fauna in NSW National Parks (Draft), Office of Environment & Heritage, Sydney

Paton D & O’Connor J 2010, ‘The state of Australia’s birds: Restoring woodlands habitats for birds’, Wingspan, 20(1), Supplement, Melbourne []

Raffaelle EA, Veblen TTB, Blackhall MA & Tercero­-Bucardo NA 2011, ‘Synergistic influences of introduced herbivores and fire on vegetation change in northern Patagonia, Argentina’, Journal of Vegetation Science, 22(1), pp. 59–71

Riches M, Gilligan D, Danaher K & Pursey J 2016, Fish Communities and Threatened Species Distributions of NSW, 2nd edn, NSW Department of Primary Industries, Sydney [ (PDF 4.8MB)]

Saunders D, Margules C & Hill B 1998, Environmental Indicators for National State of the Environment Reporting: Biodiversity, Department of the Environment, Canberra []

Simberloff D & Von Holle B 1999, ‘Positive interactions of nonindigenous species: Invasional meltdown?’, Biological Invasions, 1(1), pp. 21–32

Steffen W, Burbidge AA, Hughes L, Kitching R, Lindenmayer D, Musgrave W, Stafford Smith M & Werner P 2009, Australia’s Biodiversity and Climate Change: A strategic assessment of the vulnerability of Australia’s biodiversity to climate change, Report to the Natural Resource Management Ministerial Council, Department of Climate Change, CSIRO Publishing, Canberra []

Taylor MFJ & Dickman CR 2014, NSW Native Vegetation Act Saves Australian Wildlife, WWF-Australia, Sydney