城市生活pick谁？小型无脊椎还是大型动物群？

European ecologists were interested in understanding how animals adapt to urbanization. So they set up a variety of traps in both urban and rural areas, and assessed the body size of more than 95,000 individual critters.

欧洲生态学家们对了解动物如何适应城市生活颇感兴趣，因而他们在城市和乡村分别诱捕了一些动物，作为测量95000余个小动物体型的标本。

They measured butterflies, beetles, weevils, ground spiders, web-building spiders, moths and grasshoppers. They also tested a handful of more obscure invertebrates, like a group of microscopic shrimp-like critters called ostracods, and a group of aquatic crustaceans known as water fleas.

他们分别对蝴蝶、甲虫、象鼻虫、地面蜘蛛，结网蛛、飞蛾和蚱蜢的体型作出测量，并测试了一些界定上较为模糊的无脊椎动物，如一组称为介形虫的微型虾类生物，以及一组被称为水蚤的水生甲壳类动物。

On average, urban communities contained smaller individuals than rural ones. It’s not that cities are causing animals to evolve smaller bodies, at least not necessarily. What this study found is that animals that are already smaller seem better suited to city living. The researchers think that has to do with what’s called the urban heat island effect. Animals expend more energy going about their daily lives in warmer areas, and cities tend to be warmer than more natural areas. Smaller body sizes can compensate for that heat effect.

平均而言，城市社区比乡村地区更易接纳体型较小的动物个体。不确切地说，这并非是由于城市会让动物演化出更小的体型。本项研究发现，已进化完全的小型动物似乎更能适应城市生活。研究人员认为这与所谓的城市热岛效应相关。动物在较为温暖的地区消耗更多的日常生活能量，城市也往往比一般的自然区更加温暖。而较小的动物体型则可以补偿这种热效应。

But some groups of city dwellers were actually bigger than were their countryside counterparts.

但事实是一些栖息在城市的动物实际上往往比一些乡村的同类个体体型要大。

"For three of our groups, for butterflies, moths, and for grasshoppers, we actually saw a completely reversed pattern…these three groups, out of the 10 groups that we tested, these were the only groups where large species are also the most mobile ones."

“对于用于本项研究的蝴蝶、飞蛾和蚱蜢这三类生物群体而言，我们实际上看到了一个完全颠倒的模式......在我们测试的10类群体中，这三类群体，这些群体中大型物种也是最具流动性的群体。”

Catholic University of Louvain ecologist Thomas Merckx.

天主教鲁汶大学的生态学家Thomas Merckx如是说。

These are animals that need wide spaces, something that’s in short supply in cities, where roads and housing developments easily fragment natural habitats. Being bigger helps them move from one habitat patch to another more easily than their diminutive relatives. The results are in the journal Nature.

这些是需要宽阔空间的动物群体，但它们在城市中存量较小，因为道路和住房开发极易破坏其自然栖息地。体型较大能帮助他们比体型较小的同类个体更容易从一个栖息地移动到另一区域。此结论刊登在了自然这一国际性科学杂志上。

“As humans, we have become urban animals. So this is our new habitat. It wasn’t the case a hundred years ago. Only a tiny minority of the human population was living in cities. But urbanization really is taking off. So now more than half of humans are already living in cities, and this is only going to increase."

“作为人类，我们已成了城市动物。城市是我们现今的新居住地。一百年前的情况可不是这样的。那时只有极少数人口居住在城市。但城市化确实在飞速发展， 所以现在已有超过一半的人口生活在城市中，而且这一数据只会有增无减。”

And humans are part of a wildlife community, even in cities. We need lots of other animals, including ones we might not always think about, like moths and spiders, to thrive in cities as well. Understanding how animals are adapting—or not—to urban areas today can help us build better, more wildlife-friendly cities in the future.

人类是野生动物群落的一部分，即便在城市也是如此。我们同样需要许多其他类型的，包括我们可能并非总能想到的如飞蛾和蜘蛛等这类动物在城市中茁壮生长。了解动物现今如何适应或未适应城市地区可以帮助我们在未来建设更加适宜的，野生动物友好型城市。