Effects of urban encroachment on the use of hollow bearing trees by squirrel gliders (2013)

Strategic Research Area

Biodiversity in Rural Landscapes

Funding

Albury Conservation Company, $7273, with in-kind support from the Albury City Council

Investigators/researchers

Mitchell Francis (Honours student) with supervisors Dr Peter Spooner, Dr Alison Matthews. Dr Rachel Clancy from Albury City Council also assisted with the project.

Description

The impacts of urbanisation are becoming increasingly common as the human population continues to grow. The Thurgoona region in southern NSW is experiencing rapid urban encroachment, which is impacting upon the threatened squirrel glider (Petaurus norfolcensis). This species is listed as endangered in some states, and vulnerable in NSW. Squirrel gliders are typically found in dry sclerophyll forests and woodlands in south-eastern Australia, and the focus of local conservation initiatives. Their habitat primarily consists of large, old, hollow-bearing eucalypt trees for gliding, foraging and nesting. Therefore clearing of remnant patches of woodland vegetation in an urban landscape causes direct habitat loss and possible local extinctions. Urban encroachment has been shown to have a negative impact upon squirrel gliders, however little was known about the specific effects of urbanisation on the use of hollow-bearing trees which are often retained within an urban setting.

The project investigated the use of hollow-bearing trees by squirrel gliders, and examined the extent to which human impacts (e.g. light, noise) impacted upon the use of large Eucalyptus trees along an urban to rural environment.  Tree characteristics (e.g. girth, height, health) were recorded, and using a novel technique, infrared motion-sensor cameras were used to record the presence of squirrel gliders in more than 30 selected trees in the Thurgoona region

Squirrel gliders were found in over 50% of surveyed trees in both urban and rural areas with the older, taller trees full of tree hollows generally having more squirrel glider activity. While both excessive light and noise impacted on the gliders' use of hollow bearing trees, light pollution (associated with the density of surrounding housing) had the greatest impact on glider activity. The researchers surmised that providing suitable habitat and large hollow bearing trees are retained, and patches of remnant vegetation are well 'connected', squirrel gliders may be able persist in more 'natural' parts of the urban landscape.

Outputs

Effects of urban encroachment on squirrel gliders, Mitchell Francis, Honours thesis and journal paper in preparation.

Outcomes

Findings from this project will be used to inform conservation management approaches in the Albury area, and for urbanised landscapes elsewhere.

CONTACT

Dr Peter Spooner,
CSU-Albury
email

June 2014