Crows and magpies have found ingenious solutions to combat human attempts to remove them from urban areas, researchers in the Netherlands say.
The researchers uncovered several examples of crows and magpies actively removing bird spikes to use them for their nests instead. Several nests were recovered in the Netherlands and Belgium completely comprised of bird spikes, prompting researchers at the Natural History Museum in Rotterdam and the Naturalis Biodiversity Center in Leiden to begin looking for other examples of the unique nest-building technique, The Guardian reported Tuesday.
The researchers found numerous examples of crows and magpies using bird strips and spikes in nest-building. Evidence showed crows were in fact ripping off existing anti-bird strips rather than finding them as detritus, according to the outlet. (RELATED: Mini Pig Defends Farm From Bear)
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! 🏙️ pic.twitter.com/qen5zR2j4K
— Auke-Florian (@AukeFlorian) July 11, 2023
One magpie built its nest out of roughly 1,500 metal spikes after ripping them off a nearby hospital in Antwerp, according to NewScientist. Researchers from the Naturlis Biodiversity Center discovered that birds had pulled more than 150 feet of bird spikes from the Antwerp hospital, according to a press release from the center.
“I really thought I’d seen it all,” Rotterdam Natural History Museum director Kees Moeliker told The Guardian, adding that “[t]hese anti-bird spikes are meant to deter birds, they are supposed to scare them off, but on the contrary, the birds just utilise them.”
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). pic.twitter.com/1Aj4aF9mWk
— Auke-Florian (@AukeFlorian) July 11, 2023
“I was really struck by the irony, to take anti-bird devices and use them to their own ends,” University of Birmingham ornithologist Dr. Jim Reynolds told the outlet. While crows used the bird spikes purely for structural functions, magpies instead used the sharp metal as a defensive structure, according to The Guardian.