Poison drop to stop predation of kiwi
DEPARTMENT of Conservation rangers monitoring kiwi chicks in the remote south of Fiordland are pinning their hopes on a planned aerial 1080 poison bait drop this month to stop the repeated carnage by stoats.
For three consecutive years Tim Raemaekers and his team have flown by helicopter to Shy Lake between Wet Jacket Arm and Breaksea Sound to follow Southern Fiordland tokoeka kiwi breeding pairs and their chicks.
Each autumn they have ‘‘recruited’’ adult breeding pairs and attached transmitters to the birds.
Each spring they have tracked the kiwis to their nests, placed cameras on their nests and when the chicks were hatched attached transmitters to their legs.
In the 201718 breeding season 10 chicks were monitored and all were known or suspected to have been killed by stoats.
In the 201819 breeding season 14 chicks were monitored, two died of natural causes, and 12 were known or suspected to have been killed by stoats.
In this last breeding season, 10 chicks were monitored and nine were suspected or known to have been killed by stoat predation. One was eaten by a kea.
Mr Raemaekers said last year spring was late, the breeding season was delayed by about two weeks and they had not seen as many stoats on the footage from the nest cameras, so there was ‘‘cause for a bit of hope’’.
‘‘We did have about two chicks that made it a bit longer, we even had one that survived to 6 weeks old and left the nest completely, but the same thing happened as happened to all the others.’’
Mr Raemaekers said Doc planned to drop prefeed baits over 40,000ha on the peninsulas north and south of Wet Jacket Arm, between Dusky and Breaksea Sounds, this month.
He said a drop of toxic 1080 cereal baits would follow a minimum of five days later, in the first window of fine weather.
After the drop there would be trips to monitor pest counts through tracking tunnels and trail camera monitoring of rats and stoats.
The next breeding season would start in August or September when the team goes in to find the first nests and put cameras on them, he said.
‘‘Probably twothirds of the pairs will produce an egg and I expect most of those chicks to make it, so we are expecting quite a dramatic difference.’’
Mr Raemaekers said it could be a year or more before stoats reinvaded an area following a 1080 drop.
‘‘If we get a good cohort of chicks this year and next year, it will be quite a boost for the population,’’ he said.
Kea were also being monitored on the same peninsulas as part of the project to see how they responded to the 1080 drop.
‘‘In most cases, kea that have died following a 1080 drop have been used to scrounging food from people and so we are monitoring a small group here, in a reasonably remote site where the kea have probably never seen a human.
‘‘Our hope is that it will be quite a different rate there.’’