Cowbirds run ‘Mafia racket’ over eggs

People have long wondered how [cowbirds](http://en.wikipedia.org/wiki/Cowbird “Wikipedia Article”) can get away with leaving their eggs in the nests of other species, who then raise the baby cowbirds. Why don’t the hosts just toss the strange eggs out? Now researchers seem to have an answer — if the host birds reject the strange eggs, the cowbirds come back and trash the place.

The so-called “Mafia behavior” by brown-headed cowbirds is reported in this week’s online edition of [Proceedings of the National Academy of Sciences](http://www.pnas.org/ “Proceedings of the National Academy of Sciences” Website).

Read (AP via MSNBC)