Rope bridges to restore gene flow and reduce road fatalities of western ringtail possums

Restoring and protecting western ringtail possum populations


The western ringtail possum (Pseudocheirus occidentalis) has been declared critically endangered. It has an alarming high risk of extinction and road fatalities are a known threat (Yokochi & Bencini 2015).

Possums readily used a rope bridge installed in 2013 on Caves Road.

Mother and young western ringtail possums, together with another adult individual, cross the road using a rope bridge installed in 2013 across Caves Road between Dunsborough and Busselton, Western Australia (WA). The rope bridge has been used by multiple individuals at a rate of almost 10 crossings per night.

We have also observed multigenerational use, with mothers crossing with their young and young continuing to use the bridge after they reach independence.

We also investigated the genetic impacts of Caves Road and an artificial waterway and found that a 35m wide waterway is causing significant genetic divergence (Yokochi et al. 2016).

Therefore we are in the process of installing a rope bridge across this canal and we need to study its effectiveness at restoring gene flow while also investigating if the existing rope bridge over Caves Road has reduced road-kills.

We are looking for a PhD student who will be engaged in investigating these issues and will specifically address the following sub-aims.

Assess the effectiveness of rope bridges to reduce road kills

Road mortality is a common cause of mortality of western ringtail possums. Despite its apparent success (Yokochi & Bencini 2015), a rope bridge over Caves Road was installed much later than expected, thus negating the opportunity to investigate or detect a reduction in road mortality after its installation. The effectiveness of the rope bridge in reducing the number of road mortalities will be assessed by monitoring changes in road mortality before and after the rope bridge installation and in control sites.

Establish if rope bridges result in gene flow between groups of possums separated by barriers

Crossings of a road by animals do not always result in gene flow, and gene flow needs to be confirmed by assessing the short-term genetic changes (e.g. paternity testing) and/or long-term genetic changes (e.g. lowered genetic divergence). Monitoring of changes in home ranges before and after the installation of a rope bridge will also be conducted to see if possums cross the bridge to expand their home ranges on the other side of the road.

For more background information, see the suggested readings below.

Research team leader: Associate Professor Roberta Bencini

I mainly work on projects in wildlife conservation and management, with industry-funded projects to minimise the impacts of development and roads, road construction and other developments on wildlife.

How to apply

Interested in becoming part of this project? Complete the following steps to submit your expression of interest:

Step 1 - Check criteria

General UWA PhD entrance requirements can be found on the Future Students website.

Requirements specific to this project:

  • Existing PhD scholarship (we do not have funds for the stipend and funding is pending for the project)
  • Capacity and willingness to work in the field including at night (the species is nocturnal) and to spend a significant amount of time in the field.
  • Willingness to apply for funding to support operating costs for the project with assistance from the supervisor.

Step 2 - Submit enquiry to research team leader

Step 3 - Lodge application

After you have discussed your project with the research team leader, you should be in a position to proceed to the next step of the UWA application process: Lodge an application. Different application procedures apply to domestic and international students.


Domestic students

All domestic students may apply for Research Training Program and University Postgraduate Awards (UPA) scholarships

International students

A range of scholarships are available from international organisations and governments. The full list, organised by country, is available on the Future Students website.

In addition, all international students may apply for International Research Training Program scholarships.

Indigenous students
Indigenous students are encouraged to apply for Indigenous Postgraduate Research Supplementary Scholarships.
Forrest Foundation scholarships
All international and Australian students who wish to study towards the degree of Doctor of Philosophy (PhD) at The University of Western Australia may apply for Forrest Scholarships.

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