Most hummingbirds have bills and tongues exquisitely designed to slip inside a flower, lap up nectar and squeeze every last drop of precious sugar water from their tongue to fuel their frenetic lifestyle.

But in the tropics of South America, University of California, Berkeley, scientists are finding that some male hummers have traded efficient feeding for bills that are better at stabbing and plucking other hummingbirds as they fend off rivals for food and mates. The males weaponized bills are good not only for pulling feathers and pinching skin, but also wrestling their rivals away from prime feeding spots. Series: "UC Berkeley News" [Show ID: 34479]