Cuckoo can't fool some birds

The cuckoo is notorious for fooling other birds into hatching its eggs, but there are birds that have the ability to catch them out.

According to a new study, song thrushes have the ability to identify the eggs of "rogue" species like cuckoos in their own nests.

Auckland University researchers placed eggs in song thrushes' nests, painted to resemble their own. But the birds rejected the "foreign" eggs, particularly those with differences in reflecting ultraviolet or short-wavelength light.