One thinks of nature as "red in tooth and claw," as the old saying goes. Species compete with each other for resources, and members of the same species compete with each other for mates. There's a lot of scratching and biting going on. Unless you're a butterfly.

People love butterflies for their gentleness. According to new studies, that soft, fluttery quality persists all the way down to butterfly battles. Yes, male butterflies compete for the attentions of female butterflies. In fact, some males compete by fluttering.

Researcher Darrel Kemp, who is now at Arizona State University in Tempe, worked on an Australian butterfly called Hypolimnas bolina.

As is the case with many species, the male Hypolimnas bolinas seek to mate with as many females as possible, but the females only mate once. At any given time the vast majority of females aren't in a sexually accommodating state, and the males have to duke it out for the few who are.

How do they battle? Locking horns? Beating their chests? No. They flutter around in a circle. The two competing males never even come in contact, but at a certain point one of them accepts defeat and sails away.

What decides winner and loser in a butterfly battle? It isn't clear yet. Kemp has studied all kind of parameters, from body size to wing span.

The only consistent factor he found was age. Older butterflies--by old we mean almost three months--win out over younger ones. Maybe the kids just don't have what it takes for a hard-core flutter-off.