Eleven endangered skinks released into a gated community in Victoria’s Alpine national park could soon become 13, with a female known as Omeo due to give birth in March.
One of Australia’s only alpine lizards, guthega skinks live on “sky islands” above 1,600 metres in two isolated alpine locations – the Bogong high plains in Victoria and Mount Kosciuszko in New South Wales.
“They’re extremely vulnerable, given where they live,” said skink specialist Dr Zak Atkins, the director of Snowline Ecology.
As the climate warms, their alpine zone has been retracting, and there is nowhere higher for them to go. More frequent bushfires pose an additional threat to their survival, with multiple colonies lost in the 2003 fires.
A captive breeding program by Zoos Victoria has culminated in the release of the lizards to a specially designed enclosure furnished with granite rocks and hundreds of plants, including alpine mint bush and snow beard-heath, the skink’s favourite food.
In December, seven skinks joined an initial cohort of four. All have survived, with the imminent arrival of babies a huge milestone.
“It’s going awesome,” Atkins said. “It just looks like a normal functioning wild colony, which is exactly what we wanted.”
Dr Zak Atkins in the specially designed enclosure in the Bogong high plains furnished with granite rocks and the skinks’ favourite food. Photograph: Zoos Victoria
Scientists expect Omeo will have two babies, based on a physical examination. The skink babies, when born, will look completely different to their parents, Atkins said. Adults, camouflaged brown, grow to about a ruler’s length in size, whereas the young are tiny – about the weight of a button – and jet black with vibrant yellow spots.
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Dr Joanna Sumner, from Museums Victoria’s research institute, who was not involved in the project, said guthega skinks belonged to an evolutionary group that lived in close-knit family units. “You’ll have family groups that share a rocky outcrop. They’ll often share a place where they all go and defecate as well.”
Females from the Victorian population had very few offspring, she said, usually only one or two babies a year. “The babies will hang around with the parents. You’ll often see them basking in a pile in a sunny spot,” she said.
Atkins said guthega skinks were devoted to their burrows, often lingering near the entrance, and rarely moving more than a few metres from home.
‘Like an underground labyrinth’, the skinks’ burrows have multiple entrances, allowing them to enter at one place and pop out in another. Photograph: Zoos Victoria
These subterranean warrens enabled them to survive the winter, hibernating for five months under the snow, he said. “Like an underground labyrinth”, their burrows had multiple entrances, allowing skinks to enter at one place and pop out in another.
“They live in these burrows with their family groups for their entire lives, which we think is about 20 years.”
So it was a positive sign when the captive-bred skinks were released into their semi-wild enclosure and began digging their own homes.
Healesville Sanctuary’s carnivores and reptiles coordinator, Grace Rouget, said all 11 skinks released to the field enclosure were bred with mixed-origin parentage from Victorian and NSW colonies in the hope of one day supporting the genetic diversity of the neighbouring wild populations.
The goal is to improve the health of the Victorian population and prevent them from going extinct, as global heating threatens their alpine home.
Associate Prof Ailie Gallant, a climate scientist at Monash University, said alpine environments were highly sensitive to changes in climate. In recent decades, the length of the snow season and the amount of snow pack had reduced, and alpine areas had become more susceptible to bushfire, she said.
Rapidly and aggressively cutting emissions was the only thing that would help protect these areas from climatic changes, she said.
“We really need to make sure we protect the habitat they’re in,” Atkins said. “They’re stuck on the very top of the mountain with nowhere else to go.”
