Credit: Claire Spottiswoode

Some birds use other species' nests to lay eggs that resemble those of the other species, escaping the burdens of parenthood. Now researchers have found a type of finch in Africa that also mimics how another bird looks as an adult.

The female cuckoo finch (Anomalospiza imberbis; pictured left) lays its eggs in the nests of tawny-flanked prinias (Prinia subflava) but also strongly resembles the female of a common African species called the southern red bishop (Euplectes orix; pictured right). The resemblance, studied by William Feeney at the University of Cambridge, UK, and his colleagues, may have evolved initially to help cuckoo finches to sneak closer to the prinias' nests. But prinias have evolved what seems to be a countermeasure: they attack the finch and the southern red bishop with equal aggression.

Proc. R. Soc. B 282, 20150795 (2015)