Thread by @AukeFlorian

Bird nests made from anti-bird spikes! 🤯 Even for me as a nest researcher, these are the craziest bird nests I've ever seen. Today my paper came out on this rebellious behaviour. And it's like telling a joke...

A thread. 🧵

Ever heard of 'evil architecture'? 👿 Take for example benches that cannot be slept on, pins to prevent skateboarding or anti-homeless spikes. Here we talk about the avian equivalent: anti-bird spikes. Nasty metal spikes to stop birds from perching or nesting.

Anti-bird spikes are often used in city centres to deal with large flocks of pigeons and placed on rooftops and ledges of buildings. However, sometimes even whole trees can get covered in them. 😬 Seems that birds are not even allowed in trees anymore... 🌳📷 Anna Francis

Birds are, however, not easily scared of spikes. The Kansas Barbed Wire Museum (yes that exists! 😅) even displays a nest made out of barbered wire. 💪

And even crazier... pigeons are known to build nests with only screws and nails 🔨, and may even use drug users' syringes as nest material! 💉

Back to the anti-bird spikes. Ironically, these rows of upward-pointing spikes may be an appropriate substrate for a nest, as the pins help to secure the twigs, especially on sloping surfaces. Thanks, humans.💪

Another classic example of bird rebellion is the Parkdale pigeon. Its nest was repeatedly removed, but the more bird spikes that were installed, the better the foundation of the nest became! She never gave up. A true hero.

But now it gets more rebellious. As some birds are just done with our stupid spikes, rip them from buildings and throw them on the pavements! "Just when I thought a freak-eyed drunk guy made it to the roof, an angry Cockatoo was ripping off bird spikes."

Or take this brave bird! Clearing the whole building from anti-bird spikes. The video was originally titled 'fuck the police', so yeah, now it's getting badass. 😎 youtube.com/shorts/1FvD3Ne…

But now the ultimate finding, as we discovered that there are birds who build their nest using anti-bird spikes!! 🤯 Today we published a paper describing this behaviour: the ultimate adaption to city life! 🏙️

Let's start with crows. Crows seem to be able to build nests with anti-bird spikes! The spikes point inwards so they do not harm the bird. @HetNatuurhist in Rotterdam recently collected such a crow nest and you can see it in their museum!

Magpies also use anti-bird spikes for their nest. This nest is made out of 1500 nasty metal spikes and contains 50 meters of anti-bird strips. The ultimate rebels. Look at this incredible build! 🤯

Magpies construct a roof above their nest to protect their young and eggs from predators. For this, they normally search for thorny branches, but urban birds now seem to use these metal spikes instead. Just like in these other nests from Scotland or Enschede (NL).

The magpies appear to be using the anti-bird spikes for their nest in exactly the same way as we do: to keep other birds away. 🤯

If even bird-repellent sharp spikes are used as nesting material, apparently anything can end up in a bird's nest these days. It doesn’t get any crazier than this, does it? 😅

If you like our research and this thread, please retweet the first tweet! 🧵 Thanks to my co-authors @KeesMoeliker, @schilthuizen and Barbara Gravendeel! 👏 Read our press release and publication here (open access): https://t.co/RUVnpEi6NOnaturalis.nl/en/rebellious-…

And if you want to keep updated on my research and hear more of these weird stories on artificial nest material, then follow for more! 👋

We are celebrating the publication with this lovely ‘mag-pie’! 🍰 Officially it may be cake, but we don't care, it's tasty! Thanks for all the lovely reactions ♥️