Birds have learned to use 'anti-bird' spikes to build their nests.
Birds have learned to use 'anti-bird' spikes to build their nests Birds are stealing the spikes designed to stop them nesting on buildings and using them to build their own nests - behaviour researchers describe as the "ultimate adaptation" to city life.
Birds are stealing anti-bird spikes put up by humans - and using them to build their nests.
Magpies had ripped about 50m of anti-bird spikes from the hospital building and used them to build a huge nest of 1,500 spikes.
Anti-bird spikes are often installed on buildings to discourage birds from nesting there.
It's not the first example of unhospitable items being used for birds' nests.
Other sharp materials, including barbed wire and knitting needles, are also used by magpies for the roof of their nests. »