Male starlings that eat polluted worms suffused with estrogen-mimicking toxic waste develop beautiful songs that turn them into super-studs, attracting more females than their non-toxic brethren. The bird-ladies love a toxic dude:
Male starlings with the highest levels of endocrine disruptors in their bodies also possessed unusually developed high vocal centers, an area of the brain associated with songbirds' songs. Scientists have previously shown that estrogen drives HVC development; its mimics apparently have the same effect.
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.
These are the same chemicals that turn fish into hermaphrodites, btw.