Binningup Ringtail Study

 

 

11 April 2010

360 Environmental was commissioned by the Water Corporation to carry out a five year study of the Western Ringtail Possum (Pseudocheirus occidentalis) between the Leschenault Peninsula Conservation Park and Yalgorup National Park. This study is required by the Federal Department of the Environment, Water, Heritage and the Arts (DEWHA) as part of the approvals for the Southern Seawater Desalination Project (SSDP) located near Binningup, Western Australia (WA).

The Western Ringtail Possum is listed as Vulnerable under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act) Act and is also protected under Schedule 1 of the Wildlife Conservation Act 1950 (WC Act). Once widely distributed across southern and south-western WA, their distribution has contracted significantly over the past several decades. Much of the former habitat of the species has been removed and/or fragmented due to agriculture and urban land development.

The species occurs in and near areas of coastal Peppermint (Agonis flexuosa) and Tuart (Eucalyptus gomphocephala) dominated forest with Peppermint understorey. Important areas of conservation for the species that form key habitat within the southern Swan Coastal Plain region are:

• Core habitat: provides sites for breeding and dispersal, generally consisting of coastal Peppermint forest and Tuart forest.
• Supporting habitat: provides a buffer to key local populations and provides opportunities for foraging, breeding and dispersal.
• Corridors: provide habitat connections between areas of Core and Supporting habitat.

Crucial to the conservation of this species is the protection of key remnant habitat patches and the maintainance of habitat connections between local populations.

The aim of the five year study is to:

• Examine the presence and numbers of Ringtails between the Leschenault Peninsula and Yalgorup National Park.
• Examine what proportion of, and in what way, these possums are utilising the SSDP site.
• Examine how, if at all, these possums are accessing and moving through the SSDP site and surrounds.
• Provide recommendations as to measures that may be undertaken to improve habitat quality and connectivity between Yalgorup National Park and Leschenault Peninsula.

360 Environmental was involved in the 2006 and 2007 biological surveys of the SSDP Plant Site and associated infrastructure.  As part of that work, a regional survey for Ringtails was conducted in the area from Myalup to the Leschenault Peninsula to assess the significance of the SSDP Plant Site to the local population. Scat (poo) and head-torching surveys found evidence of a population of Ringtails that inhabits two main areas of habitat – the area around the Binningup town-site and the Taranto Road area (including the Plant Site and habitat directly to the north). In 2007 this population was estimated to be approximately 50 individuals persisting at low density.

The aim of the first part of the study undertaken by 360 Environmental in November and December 2009 has been to repeat the 2007 baseline survey. The general approach of the survey was to undertake scat surveys, drey survey, habitat assessment and head-torching for individuals. The Ringtail survey team found lots of scats at various places in the survey area – particularly in the Binningup town-site which appears to be the core of the population. The team was also able to confirm the results of the scat survey with night-time sightings of possums. This is the beginning of an exciting project and the team looks forward to keeping the Water Corporation updated on the changes in distribution and abundance over the next five years.