Help prevent window strike
The rate of kererū surviving window strike has plummeted - their survival rate has halved in recent years.
Window strike is the most common presentation for why kererū are brought to our wildlife hospital. Unfortunately, we have observed a gradual annual trend of decreasing success.
Kererū who hit windows commonly damage their coracoid bones, which can dislocate towards their hearts. (Other reasons for admission include being hit by cars, chicks falling from nests, predation by cats, dogs and kahu, and very rarely medical reasons)
In 2018 we saved 64%, that’s 37 of the 57 Kererū we treated that got a second chance.
In 2025, the rate was 34.7% which is only 17 out of 49 birds.
Why could this be?
Some theories, after chatting with our friend, Nik, at Project Kereru and doing a bit of brainstorming, is that more houses have double glazing so the glass is very tough and has no give when the birds hit it. In the past we saw many cases where a kererū smashed the window it hit and flew right through it. The injuries sustained if they break the glass are usually much less severe – due to reduced force at impact. Lots of new builds also have tinted glass which reflects trees/foliage which looks safe to fly through for the birds so they are more likely to fly into windows rather than avoid them.
You can help by putting decals on your windows
There's lots of helpful information on preventing window strike on Project Kereru's website so take a look there. Different seasons, time of day etc can be factors, as can the position of any bird feeders, and one of the easiest things you can do is add window decals which are a simple method of preventing these injuries. They reflect UV and the birds are able to see the windows and avoid them.
We often hear people say they don't like the look of decals but there are lots of different kinds, including ones that you see used in a lot of commercial buildings with simple dots that come in a tape or sheet form so there really is something for everyone in terms of 'look' to suit any home.
Order from:
https://www.projectkereru.org.nz/prevent_window_strike
or https://kererudiscovery.org.nz/shop/
Check the position of any bird feeders!
Feeding birds are very easily frightened, and if they are frightened, they’ll take wild evasive flight. If you have a bird feeder, make sure that it’s either closer than a metre or more than 9m from your window.
If a kererū hits your window and doesn’t fly away when approached, it’s not OK!
Please report it to the DOC hotline by calling O800 DOC HOT (0800 362 468).
Kererū are extremely stoic and hardy so often they are found with no evidence of injury and they don’t appear to be critically unwell. They don’t want to show any signs of weakness which means they could be a predator’s next meal.
We often get reports that “because the bird didn’t look injured we left it to wait and see if it would fly away”. Unfortunately this is not the best course of action; if the bird is on the ground and has hit a window and can’t fly it has likely sustained some very serious injuries. It is also now at increased risk of being attacked by predators. We see many window strike kererū that were also attacked by cats or dogs once they were grounded.
If you see a bird that actually looks sick that is a bad sign as it means it has no more energy to hide its injury/illness. Birds that appear sick are critically ill and this is why they have a reputation of dying at the vets. Because by the time it is noticed they are unwell it is often too late to save them.
