How Have Humans Been Outwitted by Crows?

It’s widely known that crows, ravens, and magpies are remarkably intelligent creatures. They’ve been observed using tools, are thought to recognize themselves in a mirror, and may be able to identify complex patterns.

But there’s still plenty about corvid behaviour that shocks even the most knowledgeable ornithologists. One such example was recently discussed in the Dutch journal Deinsea, a publication of the Natural History Museum Rotterdam. In an ironic twist, researchers found that birds had pulled up the strips of thin metal spikes meant to deter them from perching on buildings and other manmade structures.

And they didn’t stop there. Rather than being deterred, the crows and magpies clearly liked the look of the spikes and incorporated them into their nests, seemingly to protect themselves against predators or give structural support to their constructions.

Interestingly, the anti-bird spikes were used differently by different species. The researchers, who focused on examples in Scotland, Holland, and Belgium, observed magpie nests with spikes facing outward as a form of defense, whereas crows turned the spikes inwards.

Hostile structures: