Captive breeding success: a new population of Nangur spiny skink thrives
Near Gympie, on the Country of the Kabi Kabi People and Wakka Wakka People, live the last known wild populations of the critically endangered Nangur spiny skink.
To increase their chances of survival, the Queensland Government supported by FAME (The Foundation for Australia’s Most Endangered Species), manages a captive breeding and reintroduction program. So far, the results are promising.
Senior ecologist Daniel Ferguson said the team has released 14 Nangur spiny skinks from captivity to a new site in late 2023.
“Our team has been breeding Nangur spiny skinks from the larger wild population since 2020, with high survival rates,” Mr Ferguson said.
“Before we released the captive-born skinks into the wild, we prepared artificial burrows, to provide immediate shelter. Nangur spiny skinks are homebodies and rarely move more than a metre from their burrow, except during breeding season. We also installed monitoring cameras to observe them remotely, minimising any disturbance to the skinks and their habitat.”
Pest animals, such as feral cats, foxes, feral pigs and cane toads, eat Nangur spiny skinks. The team set up barriers around the individual burrows and the release site to protect the skinks from these predators and other animals, like deer, that can trample their habitat.
The 14 skinks joined 6 previously released during a pilot program 12 months earlier. Ongoing monitoring at the site has revealed the 20 released skinks are behaving normally.
“The cameras are recording typical skink feeding and breeding behaviour,” Mr Ferguson said.
“We knew that 5 female skinks were pregnant when we released them, and all gave birth to up to 4 young, increasing the number of skinks at the release site by approximately 20. Even more exciting is that 3 of the female skinks released in January 2023 gave birth in February 2024 to at least 6 young (at least 2 each).”
This is a significant milestone for the program as these young were conceived at the release site and include previously immature skinks bred in captivity, confirming that females mature at 3 to 4 years of age.
Weighing approximately 1.3 grams, Nangur spiny skink young are tiny when they are born. One of the challenges for the team is monitoring them when they leave their mother’s burrow, but in April 2024, they sighted more than 20 of the young. A few had remained with their mothers in the burrow, but more had moved out of home to dig their tiny burrows or take up residence in an empty, artificial burrow.
Eighteen months after the release, the team estimated the establishing population is over 50 skinks, with high survival rates and natural breeding bolstering their numbers.
The team will continue to monitor the new population while planning to reintroduce skinks to the smaller wild population, improving its genetic diversity and recovery.