Animals Are Shape-shifting in Response to Climate Change 动物正在改变体形，以应对气候变化

At a South African nature preserve where Miya Warrington， a conservation ecologist at the University of Manitoba in Canada， and her colleagues study Cape ground squirrels， the maximum daily temperature has increased by about 2.5°C in just 18 years. The animals have evolved a quiver of tactics to tolerate the regions sweltering heat， says Warrington.

Sprawling flat on the ground in a pose called splooting helps the animals shed heat from their less furry undersides. The squirrels take shady respites under their bushy tails， which they curl above their heads like tiny parasols. When its really hot， the fossorial mammals retreat to their burrows to cool off. But Warrington warns that， even with all these options for keeping cool， “still they could be at the limits of their tolerance” due to the climatic shift.

在南非的一個自然保护区，加拿大曼尼托巴大学的生态保护学家米亚·沃灵顿和她的同事在研究南非地松鼠时发现，这里的日最高气温在短短18年内已经上升了约2.5摄氏度。沃灵顿说，这里的动物已经进化出一系列耐受这个地区炎热气候的生存之道。

动物以一种叫“板鸭趴”的姿势趴在地上，可以帮助它们从皮毛较少的腹部散发热量。松鼠把尾巴卷在头顶上，像小遮阳伞一样，在自己浓密的尾巴下乘凉。当天气很热的时候，这些窝栖哺乳动物会躲在它们的洞穴里乘凉。但沃灵顿发出提示，尽管有这些保持凉爽的方法，但由于气候的变化，“它们仍然可能处在耐热的极限”。

That intense pressure could be why their bodies have begun to change shape， Warrington says. She found that， over the course of just under two decades， the squirrels already incredibly large hind feet have grown. Meanwhile， their spine lengths have become  shorter.

And the Cape ground squirrel isnt the only animal that appears to be shape-shifting in response to climate change. As scientists accumulate more evidence that many species bodies are undergoing subtle changes over a relatively short period of time， it remains unclear whether their adaptations can keep ahead of spiking temperatures—and how close they may be to a breaking point.

Youngflesh， an ecologist who is not involved in the study， sought to determine whether bird body sizes shrank temporally as climate change has driven hotter weather in areas throughout North America. “To record this change in so many species over such a short period really suggests that there is something global affecting all these birds—and climate change is what makes sense，” he says.

沃灵顿说，这种巨大的（环境）压力可能是它们的身体开始改变形状的原因。她发现，在不到20年的时间里，这些松鼠原本非常大的后脚变得更大了。与此同时，它们的脊柱长度反而缩短了。

南非地松鼠并不是唯一的因气候变化而改变体形的动物。科学家们搜集了更多的证据，证明许多物种的身体在相对较短的时间内发生了微妙的变化，但它们的适应能力是否能在气温飙升之前保持下去，以及它们离崩溃点有多近，科学家们尚不清楚。

没有参与这项研究的生态学家杨弗拉什试图查明，由于气候变化导致整个北美地区的天气变热，鸟类的身体尺寸是否会随之暂时性地缩小。“在这么短的时间内记录到这么多物种的这种变化，确实表明有一些全球性的因素影响着所有这些鸟类——气候变化就是这个影响因素。”他说。

Word Bank

evolve /i'v?lv/ v. 进化

The three species evolved from a single ancestor.

retreat /r?'tri?t/ v. 逃避；躲避

subtle /'s?tl/ adj. 不明显的；微妙的

shrink /?r??k/ v.（使）缩小