A certain circle of social media has been abuzz the past few weeks with news from Whenua Hou and Anchor Island about the kakapo breeding season.
Today an excited post announced that one female, Kuia, on Anchor Island was sitting on two eggs with maybe more on the way.
Why is this so thrilling? Kuia is the only female carrying rare genes from the last Fiordland kakapo, Richard Henry. Her two male siblings – Sinbad and Gulliver – haven’t fathered any chicks yet.
Kuia gave Kakapo Recovery rangers even more to be rapt about because she mated with two males (the lucky first-timers Blake and Kumi). More males hopefully means more diversity and a better chance of Kuia’s eggs being fertile, which isn’t a given.
Department of Conservation operations manager kakapo/takahe Deidre Vercoe said it was positive that so many young birds were breeding for the first time.
Mating activity on Anchor Island is being closely watched as so far no females have laid fertile eggs on the island. Only one female mated in 2011, but already this year the feathers are (literally) flying as males set about booming on the 1300 hectare island in Fiordland’s Dusky Sound.
Anchor Island is different from Whenua Hou/Codfish Island in that it has both rimu and beech forest – both tree species have “mast” years in which they produce abundant seed but these do not seem to be in sync with each other. That should mean that Anchor Island provides abundant food more frequently that Whenua Hou.
Vercoe said the team suspected the flurry of mating activity was driven by an abundance of beech seed, but that theory wouldn’t be proved until the birds started feeding their chicks. Kakapo breeding has previously been linked to abundant rimu seed, but this would be the first time it had been linked to beech seed – if that turns out to be the driver.
All the kakapo on the island have transmitters attached and the males’ activity levels are monitored by a software that alerts Kakapo Recovery rangers to activity that might be amorous, which is then cross-referenced with which females are nearby.
The female transmitters have a slightly different function: they monitor nightly activity and alert rangers when activity drops – normally a sign that the females are nesting.
Since mid-January, 14 females have mated on Anchor Island and four on Whenua Hou. It’s thought that with El Niño in effect this year, the rimu seed on Whenua Hou will not provide the ample food supply the birds seem to need for a bumper breeding season.
With only 125 birds left, Kuia and her brothers are the most genetically distinct from the others, which all descend from Stewart Island birds removed from the island in 1987.
Richard Henry, found in 1975, was the last surviving Fiordland kakapo. In 1998 he fathered three chicks (Sinbad, Gulliver and Kuia) and died in 2010 when he was thought to be about 80-years-old. He had different colourings to the Stewart Island birds and boomed differently: his genetics are seen as a crucial part of maintaining diversity within the remaining population.
That’s why Kuia’s so-far successful season has kakapo enthusiasts excited. It’s a lot of pressure for a nocturnal parrot living on a remote island!
Featured image: A kakapo prepares his bowl for booming, Don Merton.