每日英语听力

当前播放

一些乌鸦会攻击死去的同伴

This is Scientific American - 60-Second Science. I'm Jason Goldman. Crows react really strongly to one of their own being dead-

including gathering around their deceased comrades. Some experts believe that these so-called crow funerals are efforts to learn.

Perhaps so they can avoid the same fate. University of Washington researcher Kaeli Swift is one of those crow experts.

When a film crew came to her campus to record these behaviors, Swift and her colleagues placed a dead crow on the grass.

And they waited for the crows to show up and investigate. Just as they had done hundreds of previous times.

The first bird came in, like they do, and I'm bracing myself for what I'm expecting to be the typical response.

Which is that it alights in a tree, and it alarm calls, and then other birds come in. . . but instead what it does is it flies down to the ground, and it kind of walks up to the crow. . .

but then it goes into really typical crow precopulatory posturing. Where basically they kind of drop their wings down, and they stick their tails up, and they strut.

And it just struts on over to the dead crow and jumps on top and copulates with it. Neither Swift nor her advisor had ever heard of this behavior.

So they decided to determine just how common it is by conducting a series of experiments with wild crows in Seattle. They saw that most crows don't touch their dead-

下载全新《每日英语听力》客户端,查看完整内容
点击播放