Published on 8 April 2019

Chasing lizards on Rangitoto and Motutapu islands

What was supposed to be a weekend of shorebird counts at Rangitoto and Motutapu islands turned into a little lizard survey by surprise. Weather was crap and not very appealing to perform flock counts so instead the staff from the Department of Conservation took a bunch of us on a mini tour to check lizard traps. I'm no herpetologist and my knowledge on NZ lizards is very limited which made this little trip a great opportunity to improve my knowledge on the topic. And well, we got to see the little critters really close which was cool.

The department's staff do monitor lizard populations in the pest-free islands of the Hauraki every few months. To do so they use live traps (obviously not deadly) baited with banana. The way the traps work is very similar to a crayfish trap; easy to get in for the lizards but without an obvious way out, which makes it hard for the lizards to escape. DoC document and take measurements from each collected specimen: species, sex, snout to vent length (SVL), tail length (TL) and regeneration if the tail appears to have suffered damage in the past. Tail regeneration is a potential sign of predation and by measuring it an estimate of when an attack happened can then be inferred.

One of the highlights of the survey was a Suter's Skink, Oligosoma suteri, a species I had never seen in the wild before. This species is endemic to NZ and is the only skink of the country to lay eggs. You can read more about the Suter's Skink in iNaturalist.

The most common lizard of the survey was no doubt the Common Gecko, Hoplodactylus maculatus, with one trap having caught 28 specimens.

If you're keen to know more about NZ lizards the Department of Conservation provides great information on their website

I'm very grateful to all staff from DoC for the experience and the excellent work they do on the treasure islands of the Hauraki Gulf.