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Why did the squirrel glider cross the road?

18 June 2008

The squirrel glider is just one of the many endangered animals spared from busy traffic on the Hume Highway. Photo courtesy of David Bax.

A year ago a rope bridge was installed across the Hume Highway in North East Victoria to give native animals a chance to safely cross the road.

The bridge was the first of its kind in Victoria and the culmination of a three-year research program into the effect that roads and traffic have on wildlife.

The project was run by a team of researchers from the Australian Research Centre for Urban Ecology based at the Royal Botanic Gardens, Monash University, the University of Melbourne, and VicRoads.

Survival rates of animals near the freeway are about one-third that of animals living farther away. The study has concentrated on finding out how, where and why animals cross.

Cameras were installed at either end of the rope bridge so researchers could observe crossing attempts and successes. So far there have been 50 successful crossings of ringtail possums and almost as many partial crossings; seven partial crossings of brushtail possums; and four partial crossings by squirrel gliders.

Many "non-target" species, such as cockatoos, magpies and ravens, geckos, and large spiders have also been filmed making the journey.

The results for the squirrel glider are particularly encouraging as they are a threatened species in Victoria and New South Wales. The animal moves by gliding from tree to tree and is unable to cross large gaps in tree covers such as roads.

Since the installation of the first bridge near Benalla, a second bridge near Longwood and four glider poles at three other sites have also been installed.