Endangered Alpine Skinks Set for Population Boost as Captive Breeding Program Bears Fruit
In a significant conservation milestone, critically endangered Guthega skinks in Victoria's Alpine National Park are poised to see their numbers increase, with a female lizard named Omeo expected to give birth in March. This development follows the success of a dedicated captive breeding program aimed at bolstering the fragile population of one of Australia's only alpine lizards.
A Fragile Existence on 'Sky Islands'
The Guthega skink, a unique alpine reptile, inhabits isolated "sky islands" above 1,600 metres in two remote locations: the Bogong High Plains in Victoria and Mount Kosciuszko in New South Wales. Dr Zak Atkins, a skink specialist and director of Snowline Ecology, emphasises their vulnerability, stating, "They're extremely vulnerable, given where they live." As climate change causes their alpine habitat to retract, these skinks face an existential threat with nowhere higher to retreat. The increasing frequency of bushfires, such as those in 2003 which decimated multiple colonies, compounds the danger to their survival.
Captive Breeding Success and Semi-Wild Release
Zoos Victoria's captive breeding initiative has culminated in the release of eleven skinks into a specially designed enclosure within the Alpine National Park. This enclosure, furnished with granite rocks and hundreds of native plants including alpine mint bush and snow beard-heath—the skink's preferred food—mimics their natural environment. In December, seven skinks joined an initial cohort of four, with all individuals thriving. The imminent birth of Omeo's offspring, expected to be two in number based on physical examinations, marks a pivotal achievement in the program.
Dr Atkins reports, "It's going awesome. It just looks like a normal functioning wild colony, which is exactly what we wanted." The skinks, bred with mixed-origin parentage from Victorian and New South Wales colonies to enhance genetic diversity, have begun digging their own burrows—a positive indicator of adaptation. Grace Rouget, carnivores and reptiles coordinator at Healesville Sanctuary, highlights the goal of supporting wild populations' genetic health to prevent extinction as global heating intensifies.
Unique Biology and Behavioural Traits
Guthega skinks exhibit fascinating biological and social characteristics. Adults, camouflaged in brown and growing to about a ruler's length, contrast sharply with their young, which are tiny, jet black, and adorned with vibrant yellow spots. Dr Joanna Sumner from Museums Victoria's research institute notes that these skinks belong to an evolutionary group living in close-knit family units, often sharing rocky outcrops and communal defecation sites. Females typically produce only one or two offspring annually, with babies remaining with their parents, basking together in sunny spots.
These reptiles are devoted to their burrows, rarely venturing more than a few metres from home. Their subterranean warrens, described by Dr Atkins as "like an underground labyrinth," feature multiple entrances, allowing skinks to navigate and hibernate for up to five months under snow during winter. They reside in these family burrows for their entire lifespan, estimated at around 20 years.
Climate Threats and Conservation Imperatives
The survival of Guthega skinks is intricately linked to the health of their alpine habitat, which is highly sensitive to climatic changes. Associate Professor Ailie Gallant, a climate scientist at Monash University, warns that recent decades have seen reduced snow seasons and snow pack, alongside increased bushfire susceptibility in alpine areas. She asserts that aggressive emissions reductions are crucial to protecting these environments from further degradation.
Dr Atkins underscores the urgency, stating, "We really need to make sure we protect the habitat they're in. They're stuck on the very top of the mountain with nowhere else to go." The captive breeding program represents a proactive effort to improve the Victorian population's health and resilience, offering a beacon of hope for this endangered species in the face of mounting environmental challenges.
