Why are New Zealand’s native birds so easily decimated by introduced pests like stoats, weasels, and rats?
It’s not just that the rascals find birds’ eggs delicious.
There are a few other factors to consider, too…
For a very long time, New Zealand had no native land mammals except for the bat. Aotearoa was paradise for birds, and a diverse array of species flourished. From the tiny riroriro (grey warbler) to the many solid types of moa, avian life spread itself throughout our forests, lakes, mountains, rivers, and coastlines.
As time passed, evolution beat its drum. One of our eagles became huge, and as it swooped the skies with a 3m wingspan, established itself at the top of the food chain as a fearsome predator from above. The Haast eagle used its keen eyesight to find and pick out its prey from on high…so how did other birds evolve to escape this threat?
Birds like the kiwi and the kakapo developed beautiful camouflaged plumage which allowed them to melt into the bush, making them very difficult to spot from above. They became nocturnal, coming out under the cover of darkness to forage and find a mate. They nested in burrows in the ground, and moved about slowly in the bush. Their wings shrank from lack of use, and over time, they ended up flightless.
However, they still needed to be able to find each other to reproduce! The birds produced a very strong and distinct scent from a special gland which they spread over themselves as they preened. Their vocalisations became unique, loud, and pronounced.
Other birds like the kereru or kukupa (native wood pigeon) developed a ‘freeze’ strategy when an eagle was soaring around. Any sign of movement would be immediately picked up by the predator, so they became very good at sitting extremely still exactly where they were, until the danger had passed.
So. We were a nation of slow, smelly, loud, often flightless ground-nesters whose idea of self-preservation was to stay exactly where they were.
Then we introduced mice, rats, stoats and weasels. Fast, silent, voracious hunters utilising their highly developed sense of smell and superb hearing to find their prey. Nocturnal. Tree climbing. Burrow invading. They could even swim. These predators bred rapidly, and they would eat just about anything – eggs, fledglings, adult birds – all fair game.
It’s miraculous that we still have any native birds! Just in the last 150 years, we’ve lost so many species FOREVER. On the entire planet, only the Hawaiian Islands have more extinct bird species. It is devastating that we have let this happen.
THIS is why Predator Free 2050 is so important. Yes, an ambitious goal – but a critical one. Teach your kids about our birds – get out library books about them, encourage them in your gardens and parks by planting natives, look for them out on walks, attend events like bird releases and Conservation Week events…
This year’s Conservation Week has been wonderful – we’ve been to a themed library storytime where pre-schoolers learnt about the kakapo who has never seen a rainbow, we’ve experienced a ‘five minute bird count’ in the Waitakere Ranges, and we had our own discovery day at Kawau Island where we went weka-spotting and saw what the wallaby does to regenerating forest.
But if there’s ONE thing I’ve taken away from it all, it’s that we must all do what we can to eliminate these pests. I’m taking action and buying a Goodnature rat and stoat trap.
Goodnature traps are the epitome of great NZ innovation. They are automatic. They are humane. They reset themselves, and they are safe. They’re brilliant. You can even download an app which will tell you every time your trap has got rid of another pest, so you won’t have to be checking them all the time. Know someone hard to buy for? Christmas gift sorted LOL… you can check out Goodnature here. Just think of the difference it would make if every NZ backyard had one.
Ask your kids why they think kiwi only come out at night. What do they say?
Calling all outdoorsy mamas!
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