英语听力文摘 English Digest 409、绅士的蝴蝶（在线收听）

绅士的蝴蝶

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. And 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. That means 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; while to the victor belongs to the spoiler’s.

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 spread.

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.

有人认为正如一句古话，自然界充斥着腥牙血爪。同类相互争夺以求配偶；异类为了资源而剑拔弩张。不断上演着厮杀，除非，你是蝴蝶。

人们喜欢蝴蝶的彬彬有礼。据新研究表示，正是温顺悸动的特性让蝴蝶们远离争斗。的确，雄性蝴蝶为了吸引雌性同类会互相竞争。但是，竞争的方式仅仅是抖动翅膀。

研究人员Darrel Kemp在坦佩亚利桑那州立大学研究澳大利亚蝴蝶幻紫斑蛱蝶。

幻紫斑蛱蝶很有代表性，雄性蝶可以任意和雌性蝶交配，但是，雌性蝶一生仅一次。这意味着雌性蝴蝶不得不通过争斗来求得配偶权。

他们如何争斗呢？斗角？捶胸？都不对，他们只是在一个圈内拍打翅膀。两只雄性蝴蝶居然没有任何身体触碰，但是在某个时间已经决出胜负，而败者就自动离开。

决定输赢的因素还不是很清楚，Kemp参考了各项参数，从蝴蝶体型到翼展。

一个共同的因素在于年龄。年老的蝴蝶（超过三个月）通常会取胜，也许姜还是老的辣吧！