Using science to understand the habits of rare New Zealand lizards

In two special climate-controlled locations at Auckland Zoo, tucked away from our visitor-facing areas, we’re currently caring for the world’s entire population of cobble skinks as well as what is thought to be about a quarter of the population of Kapitia (Chesterfield) skinks. Luckily for these skinks, our conservation partners at the Department of Conservation were able to carefully collect a small number of each species and bring them to our Zoo for safeguarding just before separate cyclones destroyed most, if not all, of their only known habitats!

Looking after rare species about which so little is known takes a lot of careful observation and expertise. Adapted to West Coast conditions, special attention is given to their climate and diet, with pairs of skinks carefully assessed and introduced for breeding. We’re pleased to say their numbers have increased while they’ve been at the Zoo which is a testament to the excellent care they’re receiving. We’re working with DOC to return both species to protected habitats close to their original wild locations as soon as the two specially built facilities are completed.

To make sure these new habitats will be ideal for skink habitation, ectotherm keeper Sarah has been carrying out novel research into their dietary habits. Summer is the perfect time to study reptile diets as this is when they’re most active and therefore eating the most. She started by collecting fruits from native plants within the zoo grounds including Coprosma, Muehlenbeckia, Melicytus, Podocarpus and Dacrycarpus species, which were then offered as a part of the skinks diet. GoPro cameras were set up to record their natural feeding behaviours and see which fruits were preferred. While we’re still in the process of analysing the data and writing up this research, Sarah has noticed a distinct preference for white and blue berries over red, among both skink species – an interesting discovery that might indicate something about their former natural habitats before they were altered by agriculture and coastal erosion.

A second study is also due to start soon in a collaboration with Unitec to learn more about whether the prehensile (grasping) tail of the Kapitia skink is a reliable indicator of an arboreal way of life. This knowledge as well as the berry preference information will help us to plan which plants are best suited in their new predator-free habitats.

Zoo-based research like this is invaluable since so little is known about the natural diet, behaviour and ecology of these species, and indeed many other New Zealand lizards. The results of this type of research can be useful for herpetologists and conservationists working to save lizards throughout Aotearoa.