科学美国人60秒 SSS 小仓鸮通过分享来互相帮助（在线收听）

This is Scientific American's 60-second Science. I'm Jason Goldman.

这里是科学美国人——60秒科学。我是杰森·古德曼。

Robin Hood famously stole from the rich and gave to the poor.

罗宾汉以劫富济贫而闻名。

Young, newly hatched barn owls do something similar.

刚孵化小的仓鸮也会做类似的事情。

On average, barn owls raise six chicks at once—and sometimes as many as nine.

平均来说，仓鸮一次养育6只雏鸟，有时能达到9只。

But they don't all hatch at the same time, which means the older owlets are generally larger and healthier than their younger brothers and sisters.

但它们不会同时孵化所有雏鸟，也就是说年长的仓鸮通常比年幼的弟弟妹妹体型更大、身体更健康。

As long as the little owls remain in the nest, they're completely dependent on their parents for food.

只要小仓鸮还待在巢里，它们就能完全依赖父母喂食。

The problem is that the small rodents that they eat can't be split up.

问题是它们吃的小啮齿动物不能被分开。

So when Mom or Dad returns to the nest to feed their offspring, only one chick can eat a time.

因此，当仓鸮父母回到巢中喂养雏鸟时，一次只能喂一只雏鸟。

In many bird species, the oldest would simply outcompete the youngest, but barn owls are different.

在大多数鸟类中，最年长的鸟能轻松战胜最年轻的鸟，但仓鸮则不同。

Turns out the older, healthier birds sometimes donate their meals to their hungrier siblings.

事实表明，年长、健康的仓鸮有时会将自已的食物捐给饥饿的兄弟姐妹。

Adults in other animals species share their food.

其它成年动物会分享食物。

"It's mainly observed when males want to reproduce with females, so there (are) many (exchanges) of food.

“这种行为主要在雄性想和雌性繁殖时能观察到，因此会有许多食物交换。

Or in primates, there (are) many (exchanges) of food and grooming but only in adults."

还有灵长类动物会用食物交换梳毛，但这仅存在于成年动物之间。”

Evolutionary biologist Pauline Ducouret from the University of Lausanne in Switzerland.

瑞士洛桑大学的进化生物学家保林·迪库雷说到。

"And in chicks, it is really rarely observed. So it's quite impressive that in this species, there are so many cooperative behaviors."

“我们极少在雏鸟身上观察到这种行为。因此，令人印象相当深刻的是，仓鸮这一物种存在如此多的合作行为。”

She and her team wanted to know how this unique behavior evolved.

她和团队想知道这种独特行为的进化方式。

It could be explained by the direct benefits gained through cooperation, such as trading food for grooming.

这可能是因为它们可以通过合作获得直接利益，比如用食物交换梳毛。

Or it could be explained by the indirect benefits gained from helping others that share your genetic heritage—also known as kin selection.

或者因为它们能通过帮助有共同遗传基因的同类来获得间接利益，也就是亲缘选择。

They found that the answer was both. Younger birds groomed older ones more often than older ones groomed the youngsters.

他们发现答案是两者兼而有之。就仓鸮而言，年幼者为年长者梳毛的频率要高于年长者为年幼者梳毛的频率。

And in return, the older birds fed their younger siblings.

作为回报，年长仓鸮会喂食弟弟妹妹。

In addition, older owlets preferentially offered food to their hungriest siblings, even in the absence of grooming.

此外，即使没有梳毛作为交换，年长者仓鸮也更愿意为最饥饿的兄弟姐妹提供食物。

But food sharing only happened when the researchers artificially provisioned the owlets with extra food.

但只有当研究人员人为地为仓鸮提供额外食物时，它们才会分享食物。

So it's not that the owls risked their own survival to help their siblings.

因此，并不是说仓鸮冒着生存危险去帮助它们的兄弟姐妹。

But when there was more than enough to go around, they shared instead of hoarding.

但是，在食物有富余时，它们就会分享，而不是贮藏。

The results are in the journal the American Naturalist.

这项研究发表在《美国博物学家》期刊上。

Ducouret says that evolutionary biologists usually characterize sibling relationships as competitive or even antagonistic.

迪库雷表示，进化生物学家通常认为兄弟姐妹关系是竞争性甚至是敌对的。

But remarkably complex examples of cooperation can still be found among animal brothers and sisters.

但在动物兄弟姐妹之间仍然可以找到非常复杂的合作例子。

Seems that even newly hatched barn owls know that sharing is caring.

似乎连刚孵出的仓鸮都知道分享就是关心。

Thanks for listening for Scientific American's 60-second Science. I'm Jason Goldman.

谢谢大家收听科学美国人——60秒科学。我是杰森·古德曼。