Barn Owl Babies Can Be Helpful Hatchmates

仓鸮宝宝也有用

 

Robin Hood famously stole from the rich and gave to the poor. Young, newly hatched barn owls do something similar. On average, barn owls raise six chicks at once. And sometimes as many as nine. 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.

众所周知，罗宾汉劫富济贫。刚孵出的年轻仓鸮也会做类似的事情。平均而言，仓鸮一次能养育六只小鸡。有时多达9个。但它们并不是同时孵化的，这意味着年长的小猫头鹰通常比它们的弟弟妹妹更大更健康。

As long as the little owls remain in the nest, they’re completely dependent on their parents for food. The problem is that the small rodents that they eat can’t be split up. So when mom or dad returns to the nest to feed their offspring, only one chick can eat a time. In many bird species, the oldest would simply outcompete the youngest, but barn owls are different. Turns out the older, healthier birds sometimes donate their meals to their hungrier siblings.

只要小猫头鹰呆在巢里，它们就完全依赖父母的食物。问题是它们吃的小啮齿动物不能被分开。因此，当爸爸或妈妈回到鸟巢喂养他们的后代时，一次只能有一只雏鸟吃东西。在许多鸟类中，最老的会比最年轻的竞争更激烈，但仓鸮是不同的。事实证明，更年长、更健康的鸟有时会把它们的食物捐赠给饥饿的兄弟姐妹。

 

Adults in other animals species share their food.

其他动物种类的成虫分享它们的食物。

“It’s mainly observed when males want to reproduce with females, so there are many exchanges of food. Or in primates there are many exchanges of food and grooming, but only in adults.”

“这主要是在雄性想与雌性交配时观察到的，所以会有很多食物的交换。”或者在灵长类动物中，有很多食物和毛发的交换，但只有成年动物才有。”

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

来自瑞士洛桑大学的进化生物学家Pauline Ducouret说。

“And in chicks, it is really rarely observed. So it’s quite impressive that in this species there are so many cooperative behaviors.” She and her team wanted to know how this unique behavior evolved. It could be explained by the direct benefits gained through cooperation, such as trading food for grooming. Or it could be explained by the indirect benefits gained from helping others that share your genetic heritage – also known as kin selection.

“而在雏鸟身上，它真的很少被观察到。所以令人印象深刻的是，这个物种有如此多的合作行为。”她和她的团队想知道这种独特的行为是如何进化的。这可以用合作带来的直接好处来解释，比如用食物交换毛发。或者它可以解释为帮助与你遗传相同的人所获得的间接利益——也被称为亲缘选择。

They found that the answer was both. Younger birds groomed older ones more often than older ones groomed the youngsters. And in return the older birds fed their younger siblings. In addition, older owlets preferentially offered food to their hungriest siblings, even in the absence of grooming.

他们发现答案是两者都有。年轻的鸟更经常为年老的鸟打扮。作为回报，年长的鸟喂养它们的弟弟妹妹。此外，即使没有梳理毛发，年长的小猫头鹰也会优先向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. So it’s not that the owls risked their own survival to help their siblings. But when there was more than enough to go around, they shared instead of hoarding. The results are in the journal The American Naturalist.

但是，只有当研究人员人为地为小猫头鹰提供额外的食物时，食物共享才会发生。所以猫头鹰并不是冒着生命危险去帮助它们的兄弟姐妹。但当有足够的食物分发时，他们就分享而不是囤积。研究结果发表在《美国博物学家》杂志上。

Ducouret says that evolutionary biologists usually characterize sibling relationships as competitive or even antagonistic. But remarkably complex examples of cooperation can still be found among animal brothers and sisters. Seems that even newly hatched barn owls know that sharing is caring.

Ducouret说，进化生物学家通常把兄弟姐妹之间的关系描述为竞争关系，甚至是对立关系。但是在动物的兄弟姐妹之间仍然可以找到非常复杂的合作例子。似乎连刚孵出的仓鸮都知道分享就是关心。

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