Northland green gecko juvenile among manuka. Photo / Kiwi North
OPINION
Things are growing at Kiwi North. Back in March, the Conservation and Native Species team were excited to welcome four new residents.
Two of our Northland green gecko (Naultinus grayii) females gave birth a week apart.
Many people are surprised when they hear us tell them about our geckos giving birth.
However, all but one of New Zealand’s 100-plus lizard species (skinks and geckos) give birth to live young.
Unlike mammals, the developing embryo in our lizards is not sustained by a placenta.
Instead they are nourished by a yolk – as with egg laying animals.
This adaptation to our temperate climate is one of the incredible features that make our lizards so different from most others around the world.
Geckos will birth twins once a year, and skinks can have anywhere from two to eight offspring – sometimes more.
After observing the females, the team prepared for the new arrivals – ensuring we had a specialised juvenile habitat and diet ready.
The juvenile geckos were moved to their own habitat for easier feeding and monitoring in the first few months.
Adult geckos will out-compete the juveniles and the larger adult habitats can make it tricky to keep an eye on the growing geckos.
When the geckos were born, they were perfect miniatures of their parents – ready to hunt and catch food for themselves.
The parents don’t feed the juveniles – the gecko parents have put all the work in to get their offspring born.
A neonate (just born) Northland green gecko weighs around 1g which is the same as a paper clip, and their total length is around the width of a credit card (85mm).
At this size, they eat small invertebrates such as fruit flies, hatching crickets, small moths and caterpillars and small houseflies as well as native flower nectar and fruits.
Each of the four new geckos has its own distinctive markings, meaning that it is easy to tell them apart.
We create their own ID cards just like our driver’s license, and a file to record individual information such as their distinctive features, their parentage, and their weights and measurements.
Interestingly, three of the four new geckos are yellow with white markings (more commonly they are green with white markings).
This is rarer in Northland green geckos and it can be detrimental in the wild as they are easier for bird predators to find when they are sitting at the tops of trees.
With the right conditions and care, young geckos grow quickly.
Since March, we have observed an average of 230% increase in weight, with one gecko increasing from 1g to 4g. They have also grown longer with an average increase in total length of 50%.
All our young gecko are now more than 11cm total length.
We have been caring for the young geckos in the keeper-only area with controlled temperatures, lighting, and UV (ultraviolet).
We are able to transition this habitat into the day corridor of our native species habitats so now everyone is able to enjoy observing them growing, hunting and exploring their habitat.
You can visit our growing juveniles in the Conservation and Native Species Habitats Area at Kiwi North. We are open every day from 10am-4pm.
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