科学美国人60秒 幼鲸能被海鸥啄死（在线收听）

Gulls. You may have noticed that gulls can be pretty aggressive when it comes to grabbing food. But that behavior is more intense than you may know. Some kelp gulls snack on baby whales. Live baby whales.

海鸥!你可能已经注意到，海鸥在吃食物时，会变得非常的凶悍。但是它们那种凶悍度远远超过我们的想象。黑背海鸥竟然吃鲸鱼宝宝!是活生生的鲸鱼宝宝啊!

In the early 1970s, only a handful of southern right whales were fed upon by kelp gulls off the coast of Argentina’s Peninsula Valdez. Back then just two percent of calves every year had to suffer at the beaks of the gulls, along with some of their mothers.

在20世纪80年代初期，在阿根廷瓦尔迪兹半岛只有少数的南露脊鲸会被黑背鸥吃掉。每只有2%的鲸鱼宝宝和他们的妈妈会遭到黑背鸥的啄食。

But now, 99% of the calves have to contend with hungry gulls driving their hooked beaks deep into their backs, ripping out chunks of skin and flesh and blubber, and gobbling it up. The finding is in the journal PLOS ONE.

但是，现在99%的鲸鱼宝宝要与饥饿的海鸥作战，因为这些海鸥会将弯弯的喙深入鲸鱼宝宝的背中，扯下它们的皮、血肉以及鲸脂，然后将这些狼吞虎咽地吃掉。该研究结果发表在《公共科学图书馆》杂志上。

“Each gull has its own whale and it protects it.” University of Utah Biologist Victoria Rowntree. “Or maybe two gulls will have its own whale, and they’ll chase off any gulls that come in. And they just sit in the water waiting for the whale to surface again…They’re relentless.”

“每只海鸥都会有自己要袭击的目标鲸鱼，并会保护自己的猎物。”犹他大学的生物学家朗特里说到。“或者是每两只海鸥会有自己的目标鲸鱼猎物，它们会驱赶其他入侵的海鸥。而这两只海鸥只是停留在水面上目，等待鲸鱼再次浮出水面...海鸥是残酷的。”

Adult whales have learned to arch their backs when they surface to breathe, keeping most of their body away from the hungry gulls. But the newborns can’t do that.

成年鲸鱼在赋税水面呼吸时，已经学会拱背。因为这样可以让大部分身体避开饥饿的海鸥。但是鲸鱼宝宝还不能那样做。

“You can see the mothers getting so annoyed…when finally she’s been able to sleep, and she hasn’t arched her back, and she is isn’t horizontal to the surface, and her calf is sleeping next to her and then a gull comes along and BAMMO…I think the study I did in 1998 showed it took 30 minutes for them to return to normal behavior and not do this avoidance behavior.”

“可以看到，鲸鱼妈妈变得非常地生气...因为她们终于能够睡觉了，现在没有在水面上，不需要拱起背了，同时宝宝睡在自己身边，一切是那么的美好，可是正在这时时候，突然，海鸥来了...”我在1998年进行的这项研究表明，鲸鱼们需要30分钟来恢复常态。

More than 600 calves died between 2003 and 2014. Some years at least a fifth of all newborns perished. Researchers wonder if the gulls might be, if not responsible, then at least contributing to the pattern. Rowntree looked at whether the dead calves had more gull-inflicted lesions than those that survived, but she found that all of the youngsters get harassed.

从2003年到2014年有600多只鲸鱼宝宝死掉了。这些年，至少有1/5的鲸鱼宝宝香消玉损了。研究人员认为，即使海鸥不是凶手，但是也是这种局势的罪魁祸首。朗特里想知道，与存活的鲸鱼宝宝相比，死亡的鲸鱼宝宝身上时候有更多的海鸥骚扰的伤痕，但是朗特里发现所有的幼年宝宝身上都有被骚扰的痕迹。

It’s not that the gulls are evil, of course. They eat to survive. The challenge for these researchers is to come up with ways of protecting the whales, without simply wiping out the gulls.

当然啦，海鸥并不邪恶。它们谋食是为了生存。研究员所面临的难题是在不伤害海鸥的前提下，想出保护鲸鱼的办法。