Proof Australia’s weird telegraph poles work
IN THE 1990s, as Australia was in the middle of a highway boom, concerns were raised about the impact of building longer and wider roads.
Almost all of the proposed motorways, especially across Queensland and NSW, were going to cut through thousands of kilometres of precious habitat that Australia's animals had called their home for years.
But mammal ecologist Ross Goldingay, from Southern Cross University, had a theory that installing power poles where trees had once been could help native gliders easily cross the wider roads.
Conservations called him crazy but Dr Goldingay pushed past his detractors and now has the research to prove the sky-high poles are successful.
"I first proposed the idea of using power poles without the wires to reconnect habitat for gliding mammals 25 years ago. For some years the idea was dismissed as a thought bubble," Dr Goldingay said.
The study attached cameras to two pairs of poles in the north coast of NSW to monitor gliders using the poles from 2013-2016 and found that hundreds of sugar gliders and the threatened squirrel glider were happily and regularly using the poles to hopscotch across highways.
The study also find gliders rarely use rope bridges, a system that is popular in north Queensland and often used by animals including various species of possums and even tree kangaroos at times.
"We found that gliders use the poles 20 times more than they use rope bridges but it's hard to say the bridges are redundant because they're used so often by other animals in Queensland," Dr Goldingay said.
"We high-fived when we saw our first photo of a yellow-bellied glider on a pole. This extends the size range of species documented using glide poles."
Dr Goldingay said teams who put the poles in use trigonometry to perfectly figure out where exactly they need to be positioned.
"We use trigonometry to figure out their reasonable spacing, how tall they should be and how far they're supposed to be apart," he said.
The mammal ecologists have figured out the ratio for each of Australia's glider species, mathematically working out their fly rate.
For example, the yellow-bellied glider drops one metre for every two metres it glides while the squirrel glider's ratio is around 1.8 to 1 and the feather-tailed glider can fly for around 1.6 metres.
After working out the ratio of each glider species, ecologists can figure out how close each pole should go to the road and how high they need to be so the animals can avoid trucks.
"Some people used to say that even if they can glide across, they'll still get cleaned up by a big truck going past. If we have them high enough they can easily glide over four metre trucks.
"But every metre counts. We've had a few installations where people have stuffed it up and they struggle to get across. For example, all the poles need to be buried two metres into the ground so sometimes they forget that and the poles are two metres shorter and the gliders need to be like Usain Bolt to get across," Dr Goldingay said.
Most new highways that are built now include funding to protect wildlife and create structures that allow them to safely cross but Dr Goldingay said more needs to be done.
"These new structures have the budget for it but there are lots of freeways that have been in for decades and they need them too. There are plenty of highways that blitzed through habitats across NSW and Queensland," he said.
The NSW Roads and Maritime Service has now installed poles for gliders at more than 20 locations along the Pacific Highway upgrade.