This mountain pygmy possum at Mount Little Higginbotham has a better chance of breeding thanks to a new ‘tunnel of love’. (ABC Goulburn Murray: Erin Somerville)
A new development helping one of Australia’s critically endangered marsupials boost their love lives is starting to see action, according to scientists.
- A colony of critically endangered mountain pygmy possums is being impacted by an alpine road
- Researchers have detected differences in DNA in marsupials from each side of the road
- A new tunnel under the Great Alpine Road aims to bring the marsupials together
The narrow Great Alpine Road winding through Victoria’s high country is only a few metres wide, but for the critically endangered mountain pygmy possum it has been described as ‘no man’s land’.
Around 150 of the tiny marsupials live in a small patch of boulder field at Mount Little Higginbotham, but the hazard of crossing the Great Alpine Road that splits their habitat in two is so great for the possums that it is starting to impact their DNA.
Tests show those on the higher side of the road have genetic differences from their neighbours just several metres downhill across the bitumen.
It is worrying scientists because the dwindling population relies on genetic diversity to boost its chances of survival.
But the new ‘tunnel of love’ running beneath the Great Alpine Road on Mt Little Higginbotham is expected to help fix that.
A mountain pygmy possum is caught on camera using the new ‘tunnel of love’. (Supplied: Mount Hotham Alpine Resort)
The tunnel will help the territorial mother possums on the uphill side of the road better connect with the males, who are often kicked out of the natal grounds and forced across the road to lower grounds.
As the possums being to wake from their seven-month hibernation, the new tunnel and microchip reader are showing the $230,000 project is starting to pay off.
The new tunnel, funded by the Department of Environment, Land, Water and Planning, and by Zoos Victoria and the Mt Hotham Alpine Resort management board is not the first at Mount Hotham.
One built in the 1980s has successfully reconnected another mountain pygmy possum population across the Great Alpine Road.
With the pygmy possums continuing to face threats from climate change, fire, and invasive species, the new tunnel is being welcomed as a way to give the shy marsupials a boost in the romance department.
Bridging the romantic divide
La Trobe University wildlife biologist Dean Heinze has been monitoring the possums in the region for years.
He has observed them repeatedly and unsuccessfully trying to cross the road, which often leaves them vulnerable to threats such as cats, foxes, and cars and has welcomed the latest development.
A mountain pygmy possum is fed nectar as part of a captive breeding program at Healesville Sanctuary in Victoria. (ABC Open contributor honeycut (file photo))
“It’s a great story really, we know that these types of tunnels work,” Mr Heinze said.
“That’s been shown back in the ’80s when the first of these tunnels was put in at Mount Higginbotham, but now to have one at another site at Mount Little Higginbotham is terrific.”
Earlier tunnels relied on people monitoring possums that were ear-tagged once they were trapped.
Now advanced cameras and microchipping — similar to those used in cats and dogs — are allowing conservationists to track the possums on Mount Little Higginbotham remotely.
“No longer are populations isolated in this area, and in terms of threatened species, one of the big threatening processes is habitat fragmentation.
“By putting in these tunnels we’re at least, in part, overcoming some of that habitat fragmentation and that’s really important.”
So far around 15 individual pygmy possums have been detected using the tunnel to cross the road since they awakened from hibernation over the spring months.
Much more movement could be coming.
“In terms of at a population level, that’s quite a lot of movement of animals,” Mr Heinze said.
“We are early in the season still so there could be a lot of movement.
“Once the mothers have their babies at this higher elevation site, a lot of the babies will be pushed out of these natal areas and that’s also when the tunnel will become very important with those young moving into lower elevations.”
Love not always on time
Waiting for the pygmy possums to cross the road using the new tunnel has been an exercise in patience for the Mount Hotham Alpine Resort’s technical services and environment officer, Georgina Boardman.
Scientist Dean Heinze inspects a litter of mountain pygmy possums on the uphill side of the Great Alpine Road. (ABC Goulburn Murray: Erin Somerville)
“It went very quiet so they were slowing down and heading into hibernation and torpor,” she explained after the monitoring equipment was established in April.
But after months of waiting since the first reading, the warmer months are bringing good news.
“At the end of September, we got our second reading and from then we’ve had almost daily readings of animals moving through the tunnels which has been very satisfying for us,” she said.
Until now, Ms Boardman said she had been at a loss as to how the possums conquered the Great Alpine Road.
“We assume some of them were making their way across the road at some point in time,” she said.
“There was some genetics work done prior to the construction of the tunnel which did show there was genetic variation between the population above the road and the population below the road.
“So we know that they weren’t interbreeding as much as we would have liked.
“Part of the ongoing monitoring of the success of this tunnel will also look at the genetics in about another five years time and see how its worked from that level as well.”