This morning's newspaper: Gangster Birds People have long wondered how cowbirds can get away with leaving their eggs in the nests of other species, who then raise the baby cow-birds, writes Randolph Schmid of The Associated Press. 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. "It's the female cowbirds who are running the mafia racket at our study site," says Jeffrey Hoover, of the Florida Museum of Natural History. "Our study shows many of them returned and ransacked the nest when we removed the parasitic egg." Scientists also found evidence of what they called "farming behaviour," in which cowbirds destroyed a nest to force the host bird to build another. The cowbird then synchronized its egg-laying with the hosts' "renest" attempt.