24th January 2024

Those Pesky Stoats

Stoats are the number-one killer of many of New Zealand’s endangered native species.

Stoats live in any habitat where they can find prey. In New Zealand, they are found anywhere from beaches to remote high country, at any altitude up to and beyond the tree-line, in any kind of forest – exotic or native, in scrub, dunes, tussock, and farm pastures. They are known to live near human settlements. 

They are agile climbers, and hunt at any time, day or night. They are known to be able to swim across water gaps of up to 1.5 km to reach islands. A stoat may be able to reach land at a greater distance than it can swim by ‘rafting’ on floating material such as driftwood logs. 

Den sites are well hidden and are taken over from other animals. They include holes in tree trunks and rabbit burrows. Stoats disperse freely and individual juveniles have been known to travel over 70 km in two weeks. 

The effect of stoat predation on the survival of many of New Zealand’s bird species cannot be underestimated. They are voracious and relentless hunters, described as having only two reasons for living – to eat and to reproduce.

Stoats are known to be having a significant effect on birds species such as wrybills, the New Zealand dotterel, black-fronted terns and young kiwi. Birds that nest in holes in tree trunks such as mohua, kākā and yellow-crowned kākāriki are easy prey for stoats who can take out eggs, chicks and incubating adults in one attack.

Stoats are implicated in the extinction of South Island subspecies of bush wren, laughing owl and New Zealand thrush. Even a 3 kg takahe or 2 kg kakapo can be killed by a stoat, that also has a strategy of killing everything in sight and storing the surplus for later.

Stoats and rats are part of a complex predator-prey relationship associated with beech tree seed production. In a periodic ‘mast event’ of beech trees – where high levels of seed production occurs – stoat populations explode assisted by the increased food supply. Later, when the seed supplies run out, the higher numbers of predators have an even greater effect on populations of birds, weta, bats and landsnails.

The map below shows stoat catches for the month of January 2024:

Stoat captures over January for Southern Lakes Sanctuary groups.

Top tips for catching stoats:

  • Fresh rabbit!
  • Rebait traps as regularly as you can, studies show most pests are caught in the first 3 days or rebaiting your traps. If you are able to increase trap servicing, these summer months, Dec/Jan/Feb/March are the best months to do so!
  • Maybe try some prebaiting? I (Bonnie) recently installed a line of 5 traps out near the Gibbston highway, put a lot of fresh rabbit and eggs in the traps but did not set them. When I came back one week later a lot of the bait was stolen, so I rebaited and set the traps, came back again after a fortnight and had 4 stoats out of the 5 traps. Worth trying if you are able to check and rebait your traps regularly.
  • Scuff up the dirt around trap entrance each time you visit. The smell of freshly turned earth can be an attractant.
  • Make sure you always wear gloves, stoats don’t like the smell of humans or hand sanitiser!
  • Ensure your traps are nice and solid on the ground, no rocking around! A stoat can get scared of a moving trap, then tell all his friends and family that those scary wooden boxes are a bad idea.

Bait:

  • If anyone is shooting rabbits on their property and are interested in helping us to supply our volunteers, please get in touch! As well as this, if we have any retired butchers or hunters around that would like to help us by chopping up rabbits once a month or fortnight, give us a bell. We do try to have this chopped up for you guys as often as we can – but we need quite a lot of rabbit to get around our 3000+ traps!

Posted in: Latest News, uncategorized