The Million Dollar Mouse Programme Eradicates Mice from the Antipodes Islands

Antipodes Island parakeet (Cyanoramphus unicolor). This one is on pavement, instead of Antipodes Island.

The big news of the month is the return of the survey crew from the Antipodes Island chain with the excellent news that they were unable to find any signs of mice after two mouse breeding seasons have passed and the islands have now officially been declared free of mice.  I have been watching this process over the past several years with excitement, in no small part because I was the captive coordinator for the Antipodes Island parakeet Cyanoramphus unicolor, a unique small parrot found only there.

Yes, they are eating a bird. When you live on a cold, windswept, subantarctic island you take what you can get. The other native parrot also eats meat.

The Antipodes Islands are a series of small subantarctic islands (2,100 hectares in total) composed of the larger Antipodes Island (~2,000 hectares) surrounded by a number of much smaller islands, all formed by volcanic activity.  Due to its distance from major land masses (it is 860 km southeast of New Zealand's Stewart Island/Rakiura) Antipodes Island has an array of unique plants and animals, and as such has been designated as a World Heritage site and is protected as a Nature Reserve.  Unfortunately, mice had been a plague on the island, with estimates of their numbers being in the area of 200,000.  The mice had been there for a very long time- it is thought that they either invaded as the result of a shipwreck in 1893 or as a result of earlier sealers visiting the islands.  In that time mice have been responsible for the extinction of at least two unique species of invertebrates, a weta and a beetle.  They were also responsible for keeping invertebrate numbers, seed densities, and other types of edible plant material on the island very low due to their voracious feeding.  This limited the amount of food available for the four land birds, all of which are endemic: Antipodes snipe Coenocorypha aucklandica meinertzhagenae, Antipodes Island parakeet, Reischek's parakeet Cyanoramphus hochstetteri, and the Antipodes pipit Anthus novaeseelandiae steindachneri.  In addition, mice are known to attack and kill seabird chicks on other islands, even ones as large as albatross chicks.  The fact that several species of seabird nest only on the smaller surrounding mouse-free islands suggests that mice were killing at least some seabird chicks here as well.  Since most of the Antipodean albatrosses Diomedea antipodensis on the planet nest here, in addition to many other species of seabird, this was not ideal.  Eliminating the mouse population would help the plants (of which there are four endemic species), the 150+ species of insects (with 17% being endemics), the four species of land birds, and the twenty-one species of breeding seabirds alike.

If they are going to be at sea for years at a time, I suppose the least we can do is give them a mouse-free home when they show up for breeding.

Due to their inaccessible nature and the wild weather that often surrounds the islands, serious proposals to rid the island chain of mice had not been considered until Gareth Morgan pushed the proposal in 2012, initiating the Million Dollar Mouse project in the hopes of raising the needed $1 million.  After a large public appeal the public raised $250,000, WWF gave $100,000, the Morgan Foundation kicked in $350,000 of matching funds, and other key partners came on board to help raise the difference to make the project a reality.  Due to weather issues, the window each year to bring ships loaded with gear and helicopters (which had to be put together upon arrival) to the islands to do the work is quite short, but after several years of planning and preparation (and losing a year to humanitarian efforts because the ships were needed to help cyclone victims), in the Winter of 2016 the mouse eradication project finally was carried out.  It went smoothly and it was hoped that it had been successful, but it wasn't until the survey team returned this month that we learned that the effort had been a success.  It will be exciting to watch the return of the island to a more pristine state now that the mice are no longer upsetting the island's delicate balance.

Don't know what an Antipodes snipe looks like? Now you do!

This was a major undertaking and was far from an easy one, but it is one that all New Zealanders should be proud of.  Gareth Morgan in particular deserves a great deal of credit, for being disturbed enough by the issue initially to propose a solution and for driving the efforts (and funding) required to make this proposal a reality.  This sort of project and this sort of drive are the reasons why New Zealanders lead the planet in island pest eradications and other innovative conservation strategies.

One more parrot video, this time Reischek's parakeet. Not your typical parrot habitat and not your typical parrot as a result.