Mahoenui giant wētā come in two colour morphs – dark brown and a speckled gold. Photo / RNZ
By Robin Martin of RNZ
A captive-breeding programme that helped bring the critically endangered Mahoenui giant wētā back from the brink is expecting a bumper breeding season this summer – in more ways than one.
Not only is the purpose-built lab at the Ōtorohanga Kiwi House expecting to hatch more wētā than before, but they are likely to be the biggest yet.
Ōtorohanga Kiwi House wildlife manager Matthew Ronaldson is busying himself in the reserve’s Mahoenui giant wētā maternity centre.
“We’ve got about 30 ... what we call egg fields waiting to hatch again here this January.
“Basically, it’s an ice cream container with some soil in it that the female adult Mahoenui giant wētā can lay her eggs in after breeding.”
Then it’s a waiting game.
“Eggs can take anywhere from 10 months to two years to hatch, so we put a 10-month time limit on them and put the date when we expect them to hatch, and the last lot we actually had hatch right on time.
“You end up with hundreds and hundreds ... I think we were just over 400 juveniles or wētā that hatched last time, and that was from half of the egg fields we have in here now.”
Ronaldson is expecting up to 600 Mahoenui giant wētā to hatch this summer.
The wētā are thriving too.
“I guess having a greater food source, these animals have grown bigger than what either iwi or DoC [Department of Conservation] have seen at the Mahoenui Reserve.
“Even when we brought in our second cohort of adults, they came in a younger age, eighth and ninth instar, and they have grown bigger than the previous cohort, and we even had offspring that were bigger than the mother [when adult].”
Fully grown wētā have been through 10 development stages or instars.
Adult females weigh about 25g and are about the size of a mouse.
Wētā handler Danielle Lloyd said that was a far cry from where they started.
“If you do have hatches in there, they are really, really small – they hatch from an egg the size of a grain of rice.
“They are bright, fluorescent green when they hatch, so if you’ve got grass in there as well, it can be a bit hard to find them, so we have torches, magnifying glasses if we need them.
“We have to search through the entire thing to see what’s in there, and because they are in an ice cream container, they like to hide just under the rim on the outside.”
She’s trying to wrangle a female going by the name of Bugg-Tsunade.
“Generally, in the eighth instar, we’ll give them a name more often than not based on their little personalities, so this one’s Bugg-Tsunade.
“I actually named her after an anime I like because she’s quite feisty and I named her after a feisty character.
“One was called Bugg-Wonky. She had a wonky leg that she was able to fix through her instar changes, which they can do.
“And then we’ve had a Bugg-Chunky as well, and that was because she devoured all the food we put in there almost every day.”
Lloyd used to be terrified of giant wētā, but not any more.
“Their feet are, I guess, quite prickly, is the kind of word, on your skin, but they’re really light and you don’t really feel them on you.
“You can kind of feel them digging into you with their tarsus [final segment of their leg] when they walk.
“But it doesn’t really faze me anymore; but I guess if you’re not used to it, you probably would be a bit freaked out because it can feel like it’s stabbing into you a little bit.”
Meanwhile, Ronaldson said there was nothing to fear.
“I actually find them extremely gentle. Once you get the hang of them and they get used to being handled, as long as you’re gentle and calm with them, they’re generally calm and gentle with you.
“You may actually catch us talking with them, calling them sweetheart and all sorts of cute names, but we do become quite attached to them, our animals, and they’re just like little puppy dogs really.”
The Ōtorohanga Kiwi House is aiming to eventually hatch 3000 Mahoenui giant wētā and see them come off the critically endangered species list.
- RNZ