Estrogen-like substances in toxic waste turn male fish female; now, it turns out, they
turn male songbirds into super-smooth lotharios, capable of singing the songs that get them all the chicks, like a wave of avian
Smoove Bs:
Accordingly, the polluted male starlings sang songs of exceptional length and complexity -- a birdsign of reproductive fitness. Female starlings preferred their songs to those of unexposed males, suggesting that the polluted birds could have a reproductive advantage, eventually spreading their genes through starling populations.
(Today's word of the day is "birdsign". If you're an indie-folk songwriter, make a note of that one.)