bird nest in anti bird spikes
© Coyau / Wikimedia CommonsWhile deterring perching, bird spikes may not shift birds able to build large nests, and in fact can help them by providing a support to build the nest on.
'A brilliant comeback'

Some urban crows and magpies in Europe are building their nests using metal strips from buildings' anti-bird devices.

After finding bird nests built primarily out of anti-bird spikes and devices, researchers from the Natural History Museum in Rotterdam and the Naturalis Biodiversity Center in Leiden searched online for more cases of this phenomenon and found several examples, The Guardian reported.

"I really thought I'd seen it all," Kees Moeliker, director of the Natural History Museum Rotterdam, said, per the outlet.

"These anti-bird spikes are meant to deter birds, they are supposed to scare them off, but on the contrary, the birds just utilize them," the expert added.


Researchers found that magpies put most of the spikes on top of their nests to keep away predators like other birds and weasels. The crows used the spikes as a solid material to build the structure of their nests.

The group of experts documented their findings about this new nest type — and the magpies and crows who make them — in a study published in the journal Deinsea, an online periodical from the Natural History Museum Rotterdam.

Auke-Florian Hiemstra, the lead study author and a biologist researching animal architecture at the Naturalis Biodiversity Center in Leiden, and his co-researchers described four nests in the study — three by Eurasian magpies and one by a carrion crow — that used an abundance of anti-bird spikes. The nests were discovered between 2021 and 2023 in four different European cities: two in the Netherlands, one in Scotland, and one in Belgium.

"It feels very rebellious," Hiemstra said, according to the National Audubon Society.

"Many birds are known to use human-made elements in their nests," the National Audubon Society added in its article, noting, "the birds in the Dutch study are exceptional for having taken something so purposefully built to minimize their presence and using it to rear the next generation."
nest made of anti bird spikes
© getty; Auke-Florian Hiemstra/Naturalis Biodiversity CenterA magpie nest incorporating anti bird spikes
Both magpies and crows belong to the corvid family, a group of intelligent birds that can solve problems, per The New York Times.

"It's absolutely fascinating," Mark Mainwaring, an expert on bird nests at Bangor University in Wales, said to the outlet. "It shows just how intuitive these birds are, and it shows a certain amount of flexibility to go out and find these new materials and use them."

He added he was curious to see "if the behavior spreads if other magpies see their neighbors using these spikes in nests and think, That's how you build a nest. And the offspring raised in those nests are also going to grow up thinking it's perfectly normal and natural."

"They're outsmarting us," Hiemstra said. "We're trying to get rid of birds, the birds are collecting our metal spikes and actually making more birds in these nests. I think it's just a brilliant comeback."