迁徙动物习性（动物迁徙与气候变化）

迁徙动物习性（动物迁徙与气候变化）Ellen Aikens在美国怀俄明州大学从事博士研究，她追踪长耳鹿在绿色波浪中游走的情况。For her Ph.D. research at the University of Wyoming Ellen Aikens tracked mule deer as they surfed the green wave.气候的变化改变了全球动物的迁徙路线，以下有一新研究：气候变化是如何影响两个物种的。First mule deer. Every spring in Wyoming vegetation first appears at lower altitudes before progressing up the mountainside. Migrating mule deer follow and forage on this green wave. But as a chang

Animal Migrations Track Climate Change

动物迁徙追踪气候变化

Climate change is altering the migration routes of animals worldwide. Here’s a look at new research on how two species have been affected.

气候的变化改变了全球动物的迁徙路线，以下有一新研究：气候变化是如何影响两个物种的。

First mule deer. Every spring in Wyoming vegetation first appears at lower altitudes before progressing up the mountainside. Migrating mule deer follow and forage on this green wave. But as a changing climate leads to more frequent and more severe droughts the greenery is not as bountiful as it used to be.

首先是长耳鹿。每年春天，在美国怀俄明州，植被都是首先出现在低海拔，然后向山上延伸。长耳鹿跟随着绿色的波浪迁徙觅食，但是由于气候变化导致更频繁更严重的干旱，植被不再像过去那么丰富了。

For her Ph.D. research at the University of Wyoming Ellen Aikens tracked mule deer as they surfed the green wave.

Ellen Aikens在美国怀俄明州大学从事博士研究，她追踪长耳鹿在绿色波浪中游走的情况。

“The green-up lasted across the landscape for about half as long in drought years in comparison to wet years. And also the order of green-up along these routes were less sequential. So in essence drought compresses and reshuffles the green wave and just makes it so that this foraging bonanza that deer depend on in their spring migration is really compressed in time.”

“与雨水年份相比，干旱年份绿化持续时间只有雨水年份的一半。并且，绿化在这些地方已经没有那么延绵不断了。所以根本上来说，干旱的压力，改变了绿色波浪，同时长耳鹿在春天觅食区域也随之减少。”

And although the deer were able to keep up with the faster green wave the nutritional value was lower—leaving the animals less prepared for the challenges of the year ahead.

即使长耳鹿能够跟上更快的绿色波浪，但是营养价值变得更低了——这使得它们对下年的挑战准备不足。

Meanwhile in Europe the population of Bewick’s swans that spend the winter in the United Kingdom and the Netherlands is declining. But when researchers looked at the data more closely they found an increase in the wintering population of swans in Germany. It turns out that since the 1970s the swans’ wintering habitat has shifted an average of 13 kilometers to the east each year.

与此同时，在欧洲，在英国和荷兰地区过冬的Bewick’s天鹅正在减少。当研究者进一步查看数据发现，在德国的天鹅数量在上升。这表明自1970年以来，过冬的天鹅每年以13公里向东部转移。

“What we think is that the swans like to spend time in areas where it’s five degrees Celsius. And this isotherm has shifted in the same rate as the swans shifted eastward. So that’s a strong indication for us that the swans actually move with this temperature line.”

“我们认为天鹅喜欢5摄氏度的区域，这一等温线正以同样的速度向东偏移。所以我们肯定天鹅与这一等温线一同移动。”

Rascha Nuijten of the Netherlands Institute of Ecology. Her team also found that the swans were spending less time in their winter homes before flying back to the Russian tundra to breed.

荷兰生态研究所的Rascha Nuijten说道，他的团队还发现，在飞回俄罗斯苔原繁殖之前，天鹅呆在过冬地区的时间短了。

Neither the mule deer nor the Bewick’s swan is endangered but the findings have broader importance for our understanding of the conservation of migratory animals.

长耳鹿和Bewick’s天鹅都处于危险中，这一发现更让我们知道保护迁徙动物有着更广泛的重要性。

“If you start thinking of protecting a certain plot of land it’s not just the current situation that is there. Nature is dynamic. And the species that are present now might not be present in 10 years’ time—and not because we didn’t protect it but maybe because these species are actually dynamic in their ways. And we need to include this resilience and the dynamics of nature into our legislation and management.”

“如果你开始认为保护某块土地，这不仅仅是当前状况，自然是动态的。在这里出现的动物可能10年后不会再出现——不是因为我们不保护它，而是由于物种是以它们的方式动态变化的。我们需要把自然的弹性和动态纳入到我们的立法和管理中。”