Professor Darryl Jones, a Griffith University ecologist, found he had to "eat his words" after research showed that within three weeks koalas were regularly using the bridges and tunnels built for them.

"We found that if we put in the structures and put in the fences – so they could not get on the road – then they had to seek other ways to get from A to B," Professor Jones said.

"I thought these are not an intelligent animal, they spend their time high on eucalyptus oil and you would not call them innovative," Professor Jones said.

"And I had to eat my words, because they worked out a way to do something that I never thought they would do in their evolutionary history."

One trick is to avoid water. By removing the risk of them getting their paws wet they will use drains and culverts which have been converted into underpasses.

"Most mammals will refuse to walk into water, they just don't like getting their feet wet," Professor Jones said. "So we came up with this idea of putting up a ledge along the side of the culvert and the animals can use those when you put up a fence," he said.

​In 2013 Fairfax Media reported 10,956 of the 15,644 south-east Queensland koalas that died between 1997 and 2011, were struck by cars, mauled by dogs, or died of stress-related disease.

He said it was imperative to address the "absolutely shocking" 80 per cent decline in the koala population in Queensland's Redland and the nearby "koala coast". "That is just so 'heading towards extinction' it is horrifying," he said.

But he is now somewhat optimistic.

His research goes back six years. It shows that between 2010 and 2012 the bridges and tunnels built in the Moreton Bay and Redland council areas were used 130 times and now literally thousands of times.

The first major smart mammal bridge and tunnel was built more than a decade ago on Kuraby's Crompton Road between Karawatha Forest and the Kuraby Bushlands.

It includes a land bridge, tunnels with ledges, and rope ladders for gliders and possums.

"Right at the peak of the time, we had 45 animals using this structure - and every other structure here - every single night of summer," Professor Jones said.

"And that was the biggest surprise."

A paper into this research was published by the CSIRO on Tuesday.

Professor Jones studied these seven successful tunnels and bridges.

Mt Cotton Road, Burbank, Brisbane City. Koala overpass. A purpose-built steel gantry.

Redland Bay Road, Capalaba, Redland City. A dry timber ledge in two drains.

Moreton Bay Road and Old Cleveland Road, Capalaba, Redland City. Underpasses with fencing.

Cleveland-Redland Bay Road. Dry ledges built on all four underpasses with fauna fences.

Dayboro Road, Petrie, Moreton Bay Regional Council. Large open bridge underpass.

Anzac Avenue, Kallangur. Gravel fauna pathways under bridge with fauna fences.

Compton Road overpass at Kuraby. It includes canopy bridges, ledges and glider poles.

Bigger structures like bridges have to be constructed when the road is being built, or widened (Compton Road at Kuraby), but smaller, effective changes can be made at any time.

Drains which are always placed under major roads can become underpasses.

Major "koala kill" hot spots were identified, including Mt Cotton Road and Mt Gravatt-Capalaba Road.

"Now several of these structures are getting koalas under the roads in these areas," he said.

Professor Jones said the most striking part of the research was that mammals will seek out and use the bridges and tunnels if they are built into the transport network.

"The most striking thing is that they actively used these structures we provided for them almost straightaway," he said.

He said the most striking finding of the research was that mammals, including koalas, echidnas, wallabies, kangaroos, possums gliders as well as koalas, will seek out and use the bridges and tunnels if they are built into the transport network. 
"As soon as they worked out they could use them, they used them regularly."

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