It’s commonly assumed that cities are wildernesses for wild animals. In fact, wild animals often thrive in cities: everything from magpies and lorikeets, to bandicoots and possums in Australia, to coyotes and white-tail deer in America – even cougars in suburban Los Angeles (the four-footed kind, to be clear).
Why wouldn’t at least some wild animals thrive, after all? From parks and gardens, to garbage bins and roof cavities, humans liberally sprinkle their habitations with all manner of food and shelter for other animals.
And animals are nothing if not adaptable. As I’ve reported before on the BFD, wild cockatoos have shown remarkable abstract thinking and learning ability in order to thwart human efforts to keep them out of the wheelie bins. Other birds are proving just as smart and adaptable.
Urban birds have long used urban objects to make their nests. In recent years, researchers have found things like condoms and cigarettes threaded between sticks and moss. But they were recently surprised to find that birds had started using another object in their nests – anti-bird spikes, which are supposed to deter birds from roosting on buildings.
Going one further than cockies using their smarts to get past locked bin lids, or keas stripping trim from parked cars, these birds are giving the, well, bird to measures designed to keep them away.
“I really thought I’d seen it all,” Kees Moeliker, director of the Natural History Museum Rotterdam and one of the authors of a new study on the anti-bird spike bird nests, remarked to the Guardian. “I didn’t expect this. These anti-bird spikes are meant to deter birds, they are supposed to scare them off, but on the contrary, the birds just utilise them.”
According to the New York Times, this nest-building trend was first noticed by Auke-Florian Hiemstra, a biologist who studies how animals use human materials. In July 2021, Hiemstra noticed a Eurasian magpie nest studded with hundreds of anti-bird spikes in Antwerp, Belgium.
“[W]e also describe it in the paper as the biggest nest we found, a nest that included more than 1,500 nasty, metal, anti-bird spikes,” Hiemstra told NPR. “Fifteen hundred – so that’s like a bunker for birds.”
Nature, as Jeff Goldblum’s character famously said in Jurassic Park, finds a way. When, for instance, humans build soaring vertical structures, falcons who normally nest on cliff faces turn that to their advantage.
As it happens, Eurasian magpies normally protect their nest bowls with a roof of thorns in order to ward off predators. So, when humans so helpfully supply them with even more durable sharp, spiky things than ever, why wouldn’t the birds improvise, adapt and overcome?
The magpies in Antwerp, however, turned to the anti-bird spikes instead, apparently ripping them from the side of a nearby building. The spikes are turned outward, while the inside of the nest is soft and warm for the chicks.
“And this is, I think, crazy,” Hiemstra said to NPR. “They use the bird spikes in the same way as they were intended to be used, namely to ward off other birds… And I think that’s just perfect.”
The bird-spike adaptation has also been observed in corvid species from Rotterdam to Glasgow.
It’s just the latest in a long tradition of birds using human, urban objects for nest-building.
As the Guardian reports, a South African museum found a crow’s nest in 1933 that used materials like copper, galvanized iron, and barbed wire. In recent years, Hiemstra has found birds nests packed with windshield wipers, sunglasses, plastic carnations, and bags used for cocaine.
“Almost anything can become part of a bird nest,” Hiemstra told the New York Times.
Naturally, environment writers are clutching their pearls over wild animals making do, like wombles with human rubbish. But naturalists don’t see a problem.
“We should not deter birds, we should embrace birds and live together with them,” Moeliker told the Guardian. “These birds are very smart and they always find ways to cope with the harsh urban life. I’m very sympathetic towards these crows and magpies. They are my heroes.”
Hiemstra seconded him, telling NPR: “[The nest phenomenon] really reflects how animals now are adapting to our urban city life… I think it’s magnificent to see these rebellious birds actually fighting back.”
All That’s Interesting
Nature finds a way, indeed.
