June 2008. Early success in protecting native animals from roads and traffic
Our thanks to Dr van der Ree for his help and images of the Australian rope bridges.
June 2008. Preliminary results of a study into a wildlife rope bridge in Australia, the first one built in Victoria, indicate early success in helping protect native animals from the effects of roads and traffic.
"We have early proof that our native animals are regularly crossing the purpose built rope bridge over the Hume Highway near Benalla, and many other animals are investigating the bridge," said Dr Rodney van der Ree, Ecologist at the Australian Research Centre for Urban Ecology (ARCUE) and Honorary Fellow, School of Botany, University of Melbourne.
"These early findings are impressive as they show that native animals have acclimatised to the 70 metre rope bridge and are using it to cross the highway to find food, shelter and mates," said Dr van der Ree.
Squirrel gliders, Ringtail & Brushtail possums
Since June last year researchers have observed 50 crossings of Ringtail Possums and almost as many partial crossings, seven partial crossings of Brushtail Possums and four partial crossings by Squirrel Gliders.
Dr van der Ree said the results for the Squirrel Glider are particularly encouraging as they are faced with the threat of extinction in Victoria and New South Wales. "The animal moves by gliding from tree to tree so where there are large gaps in tree cover, such as roads, it is unable to cross," said Dr van der Ree.
Other wildlife bridges
- Rope bridges have been in use at Diani beach in Kenya for around ten years. They were designed to protect the local colobus monkey population, and the current 23 bridges are thought to be used some 150,000 times per year.
- Utah built a wildlife "Overpass" in 1976 which has been much copied, and improved worldwide, and especially in North America.
- Wildlife "Underpasses" are becoming more and more common. From small pipes to allow toads to migrate, to huge box culverts designed to allow bears and even moose to pass through.
Animal crossings
The three year project involves the Australian Research Centre for Urban Ecology based at the Royal Botanic Gardens Melbourne, The University of Melbourne, Monash University and VicRoads and has focussed on finding out how, where and why animals cross the busy freeway. Relying on specially installed cameras at both ends of the rope bridge which record the time and date on each photograph, the researchers establish which animals are making an attempt and which are making it all the way across the bridge.
Other species crossing
"We have also gathered information on other species, for which the rope bridge wasn't originally intended, such as cockatoos, magpies and ravens, the occasional gecko, and large spiders, so this is a bonus," said Ms Kylie Soanes, Research Assistant at the School of Botany, University of Melbourne.
Second bridge
A second bridge near Longwood and four glider poles at three sites have also been installed.
"VicRoads is fully committed to ensuring that the fauna which lives near our roads is protected during the construction and operation of any road network," said Graham Freestone, VicRoads Regional Director for North Eastern Victoria. "The rope bridge and glider poles are being used to test the effectiveness of such structures in assisting animals to cross the road, this information will then be used by VicRoads in planning future road projects," Mr Freestone said.
The research is being funded by the Australian Research Council, ARCUE and VicRoads.
