Female warblers love a man who knows his way around town. And she can tell who that is simply by listening to his call, according to a study published online in the journal Animal Behaviour. Researchers found that older great reed warbler (Acrocephalus arundinaceus) males were more accomplished singers than younger males, being able to perform tricky double-syllable whistles, compared with the monosyllabic whistles of younger males. Also, the more a male—young or old—remained true to a particular locale, the more consistent his performances were. Males with the most sophisticated and consistent whistles had the largest harems, suggesting that females are listening for a mate who knows where to find food, build nests, and avoid predators in the region.
See more ScienceShots.