FACT SHEET DECEMBER 2020

Western Ringtail Possums Regional Surveys

Images courtesy of G Harewood and Biota Environmental Sciences

In 2019, as part of The surveys were recognised in Main Roads Environment team recognised development for Bunbury December 2020 by the Institute of Public a gap in the information available for Administration Australia (WA), winning the population and location of Western Outer Ring Road (BORR) its award for Best Practice in Social Ringtail Possums in the region. The team project, Main Roads Corporate Values. spearheaded a campaign to conduct a made the decision to Western Ringtail Possum Regional Survey expand its environmental Background Project beyond the scope of the BORR Western Ringtail Possums are only found project to include the entire South West investigations, beyond in the south west of . and Great Southern regions, from Lake the project scope and in Threats to Western Ringtail Possum Clifton to Albany. turn, provide an invaluable include habitat loss and fragmentation The lack of reliable information on resource for environmental from development, introduced predators, Western Ringtail Possum populations climate change, fire and logging. managers, regulators, has been a key impediment to the universities, researchers and In 2017, the International Union for development of effective conservation Conservation of Nature assessed the efforts to protect the . environmental groups across of the species as Australia and the world, “”- a step away The Surveys working to protect the future from “extinct”. In May 2018, the Federal Between August 2018 and August 2019, of the Western Ringtail Department of Agriculture, Water and Main Roads Environment worked with the Environment also listed the species as consultancy Biota Environmental Sciences Possum. critically endangered. to develop the survey methodology. The survey included walking 1,287 Ringtail Possum density, which takes into collaboration between government, kilometres of transects, over an area of account the probability of detecting the industry and environmental advocates. 114,234 hectares, across 40 sites to survey being surveyed and the size of To ensure the best outcomes, Main Roads Western Ringtail Possum populations. the area being examined. consulted with or employed the services A transect is a straight line through an The survey data indicated a population of: animal’s habitat through which the team estimate of 20,118, from the survey sites. •• Department of Biodiversity, travels, recording sightings along the This estimate is six times more than the Conservation and Attractions; way. For the survey, the transects were 2015 population estimate of 3,400 mature •• Western Ringtail Possum Recovery generally 75 metres apart and were individuals for the entire species. Team (includes researchers from the walked for approximately 6 hours after There are likely to be many more Western University of Western Australia, Edith sunset. Each member of the survey team Ringtail Possums in the overall population Cowan University, representatives walked transects using GPS to navigate as the Regional Western Ringtail Possum from the local community, South West and accurately record animal sightings. estimate did not include surveys in all Catchments Council, Forest Products The Project’s use of innovative survey available habitat, and excludes possums Commission, Nature Conservation techniques led to the trial of aerial drones around inland forest rivers, in urban and Margaret River Region and the Cities of with heat sensing cameras to locate peri-urban areas or agricultural areas. Mandurah and Busselton); Western Ringtail Possums in vegetated The results of the regional survey also •• Biota Environmental Sciences areas along Bussell Highway near address some of the information gaps (environmental consultancy specialising Busselton. identified in the Western Ringtail Possum in biological surveying), and Recovery Plan, and provide a useful •• Analytical Edge (statistical consultancy). The Results framework to understand the trends in The survey utilised a methodology population abundance and distribution Further information originally developed by the University of into the future. To find out more about Main Roads’ St Andrews in Scotland and was adopted environmental practices and initiatives, for the project following consultation A Collaborative Approach visit our Environment page at mainroads. with the Department of Biodiversity, The Western Ringtail Possum Regional wa.gov.au Conservation and Attractions and the Survey project represents a new Western Ringtail Possum Recovery Team. benchmark in best practice for estimating The survey team used line transect the species population and demonstrates distance sampling to estimate Western what is possible through genuine

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