帮助候鸟寻找安全的迁徙之路(4)

There’s lots of evidence that’s been growing over probably more than a century at this point where we might see birds colliding with communication towers.

鸟类与通讯塔相撞的情况已经存在一个多世纪了，而且有证据表明这种情况越来越多。

It’s not the tower that they’re colliding with, it’s usually the guy wires.

但鸟儿撞到的不是通讯塔，通常是拉线。

But why are they circling around a communication tower?

但鸟儿为什么要围着通讯塔转呢?

And usually the light on the communication tower, they are entrained into that light. They circle around it.

因为鸟儿通常会被通信塔上的光所吸引，它们被带进了那束光里，围绕着光转圈。

They’re calling, giving these flight calls, and then they collide with something that they ultimately didn’t see, the guy wires supporting the communication tower.

鸟儿发出叫声，对着鸟群发出叫声，随后它们就撞上了它们最终没有看到的东西，也就是支撑着通讯塔的拉线。

These towers have bright lights on them to prevent aircraft from flying into them at night.

通讯塔上明亮的灯光是为了防止飞机夜间飞行撞上它们。

But this visual deterrent unfortunately has the opposite effect on birds.

但不幸的是，这种视觉妨碍物对鸟儿产生了相反的效果。

We see evidence of this of birds colliding with skyscrapers. And they're colliding with the windows.

我们看到鸟儿与摩天大楼相撞的证据。鸟儿会撞到窗户。

But why are they flying into the building?

但鸟儿为什么要飞进大楼呢?

It’s not to say that birds collide with trees on a given night when they’re migrating.

并不是说，鸟儿在夜晚迁徙时会撞上树木。

They can perceive obstacles, but they couldn’t perceive the glass on the building at night.

鸟儿可以感知障碍物，但在夜间却无法感知大楼上的玻璃。

Essentially Kyle and his team found that more lights on skyscrapers leads to more dead birds.

凯尔和他的团队发现，大体上，摩天大楼上的灯光越多，死亡的鸟儿就越多。

So that’s why we think about light as a pollutant for these birds.

这就是为什么我们认为光对这些鸟来说是一种污染物的原因。

It’s taking them off course. It’s reshaping where they’re on the landscape.

这让鸟儿偏离了飞行路线，使鸟儿重塑它们在景观中的位置。

We can see more birds in urban centers than we would otherwise expect, and light keeps coming up as a common attractant.

我们可以在城市中心看到比我们预期更多的鸟类，光线作为一种常见的引诱物不断出现。

The problem with artificial light is especially visible at the Tribute in Light memorial.

“纪念光碑”中的人造光问题尤为明显。

We see this in New York City, one of the most photo-polluted cities in the lower 48 states of the United States.

“纪念光碑”位于纽约市，纽约市是美国本土48个州中光污染最严重的城市之一。

When we go there on September 11, when the towers of light are set up to remember the lives lost during the terrorist attacks, there's no missing them.

9月11日，建立这座光塔是为了纪念在恐怖袭击中失去的生命。当我们于9月11日抵达那里时，它们也不会错过。

They cast miles up into the airspace; you can see them from upwards of 60 miles away on the horizon.

灯光投射到几英里外的空域; 你可以在60英里以外的地平线上看到光束。

Birds flock to those lights en masse.

鸟儿成群结队地飞向那些光束。

We see thousands of birds, warblers, circling the towers of light.

我们看到成千上万的鸣鸟在这座光塔上盘旋。

In that case, there’s not ultimately a structure associated with those lights, but the birds are very clearly attracted to those lights.

在这种情况下，这并不是因为与光有关的建筑物，而是这些鸟儿显然会被这些光所吸引。

The lights go on; the birds show up. The lights go off; the birds dissipate.

灯亮着; 鸟儿出现了。灯熄灭了; 鸟儿飞走了。

And night flight calls also seem to be impacted by light pollution.

夜间飞行的鸣叫声似乎也受到光污染的影响。

Scientists aren’t entirely positive why birds produce night flight calls, but when they make these calls reveals some clues.

科学家们尚不明确鸟类为什么夜间飞行会发出叫声，但鸟类发出叫声的时间揭示了一些线索。

Birds emit night flight calls more frequently during poor weather conditions, such as fog and rain.

在如雨雾等恶劣的天气条件下，鸟类在夜间飞行时会更频繁地发出叫声。

They also call more when disturbed or flying in particularly dense flocks—and, it turns out, when they encounter light pollution.

当鸟儿受到干扰或在尤为密集的鸟群中飞行时，它们也会发出更多叫声——研究证明，当鸟儿遇到光污染时也是如此。

This suggests that the night calls might play a role in birds’ flocking dynamics—sort of an attempt to keep one another safe.

这表明，夜间鸣叫可能在鸟群动态行动中发挥了作用——某种程度上是为了保证彼此的安全。

As birds call out when they’re disoriented in light pollution, however, it attracts even more birds into the light, putting more individuals in danger of running into objects and killing them.

然而，当鸟类在光污染中迷失方向时，它们会发出叫声，这会吸引更多的鸟类进入光中，使更多的鸟类处于撞到物体导致死亡的危险之中。

To combat this problem, BirdCast is working to get anti-light-pollution-proactive.

为了解决这个问题，BirdCast正在积极行动，阻止光污染。