As a form of “beautiful revenge,” birds are building their nests on anti-bird spikes in cities.
Anti-bird spikes have been put up in many places around the world to keep birds from landing on statues and balconies. But it looks like the birds are now finding a way to get back at them.
Have you ever seen those sharp metal pins that are put on buildings to keep birds from making nests? These are called “anti-bird spikes,” and they’re meant to make it hard or dangerous for birds to land on the surfaces. But some birds, mostly Corvidae like crows and magpies, have figured out how to use these spikes to their advantage. They build their homes out of them!
Researchers from the Netherlands have found evidence of birds using anti-bird spikes to make their nests safer in cities across Europe. The birds take the spikes off of the buildings and bring them to their nests, where they set them up so that the spikes form a thorny fence around the eggs and chicks. This is what the experts call the best way to adapt to city life.
“The fact that they’re using these bird-proof spikes to protect their nests is like the perfect comeback,” Auke-Florian Hiemstra, who led a study on the strange nests, said in an interview. “These sly birds are smarter than we are.”
Researchers watched how the birds behaved in “hostile” buildings in Scotland, Holland, and Belgium. They discovered that the birds took the spikes off of the buildings and put them in their nests, pointing them outwards to protect themselves from competitors and predators.
One of the most impressive cases of this behavior was seen in the courtyard of a hospital in Antwerp, Belgium. There was a magpie nest with about 1,500 spikes that covered 50 meters. It was called “an impregnable fortress” and “a bunker for birds” by the researchers. The magpies took the spikes off the hospital roof, leaving only glue marks behind.
Other birds have been known to steal magpies’ eggs and young, so they build roofs over their nests. Most of the time, they do this with thorny plants or twigs with sharp points. But in cities, where natural materials are hard to come by, they use things that people have made, like bird spikes, sharp wire, or knitting needles.
Crows build their nests with bird-proof spikes too, but they do it in a different way. They put the spikes on the roof of their nests and point them inward to make a mesh that holds the nest up. So, they don’t hurt themselves or their children with the sharp pins.
The birds may be able to handle ecosystem loss and fragmentation, climate change, and pollution better because of this behavior. It may also help them have more babies and stay alive longer. But there may also be some risks when using anti-bird spikes, like getting hurt, getting an illness, or getting caught.
The researchers say that this behavior shows how smart and flexible these birds are because they can use man-made things to their advantage. They also think it’s “beautiful revenge” because the birds are making more birds out of the things people made to keep them away.
