Hope to give skink chance

WHILE it is only 12cm long and weighs no more than a teaspoon of sugar, the ‘‘nationally critical’’ cobble skink is subject to huge efforts to protect it.

Until recently, their future was in doubt.

To prevent extinction, the Department of Conservation responded proactively and decided to move about 40 of the skinks from their West Coast home to Auckland Zoo to give the native species a second chance at survival.

Shortly after their move, their coastal habitat was devastated by Cyclone Gita.

Since then, the captive population has reached 140 individuals, but their low number means they are still nationally critical.

University of Otago zoologist Dr Ludovic Dutoit hopes to change their fortunes after winning research funding from the 2023 Auckland Zoo Small Grants Programme.

He will work with Otago zoologist Prof Bruce Robertson and Auckland Zoo ectotherms team leader Don McFarlane to explore molecular sexing as a tool for the conservation of the skinks.

Dr Dutoit said the problem with cobble skinks was, when they were young, it was difficult to know which were male and which were female.

‘‘You can only determine their sex when they are adults.

‘‘One of the problems is that males fight with each other in captivity — they start fighting before we can know which ones are males and females.

‘‘Such fights are a difficult challenge for captive management.

‘‘They can injure each other and that’s not very practical.

‘‘Determining the sex of individuals is essential for planning future mating and accurate population viability analyses.

‘‘For all these reasons, developing a molecular method for the sexing of juvenile cobble skinks is critical.’’

They would use cuttingedge genomic techniques to develop a genetic approach to determine the future sexing of the skinks, he said.

Back from the brink . . . University of Otago zoologist Dr Ludovic Dutoit has received funding to research more efficient breeding of the nationally critical cobble skink. Right: A cobble skink at Auckland Zoo.

Once the molecular test was developed, it would be incorporated into the management of the captive population, and males would be separated before they started fighting.

‘‘That will make a big difference to the population. It will lead to much more efficient breeding.

‘‘Further, the sequencing of these samples will allow us to determine levels of genetic diversity and inbreeding in one of Aotearoa’s rarest mokomoko [lizards].’’

The ultimate goal was to start reintroducing the skinks to the wild but, first, further breeding and finding a suitable home was the top priority.

‘‘It’s an exciting time.

‘‘With a little bit of will, this could potentially make a big difference to the conservation of this rare species.

‘‘This test is the first of its kind for a New Zealand skink and should be adaptable for sexing other New Zealand skink species.’’