科学美国人60秒 SSS 鬣狗的社会等级（在线收听）

This is Scientific American — 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。

Turns out that for hyenas, it's not what you know, but who you know.

事实证明，对于鬣狗来说，重要的不是知道什么，而是你认识谁。

Spotted hyenas live in large, mixed-sex clans with fairly stable social hierarchies—and the females are in charge.

斑点鬣狗生活在大型的雌雄混居的家族中，这种家族的社会等级相当稳定，而且由雌性主导。

"The matrilineal hierarchies that we see in spotted hyenas are also found in a lot of Old World monkeys."

“我们在斑点鬣狗身上看到的是母系等级制度，这在许多东半球的猴子身上也发现过。”

Michigan State University biologist Eli Strauss.

密歇根州立大学的生物学家伊莱·斯特劳斯说到。

"It's been perplexing for a long time to a number of people: what forces maintain this system? Because it is somewhat unusual in the animal kingdom."

“长期以来，令许多人困惑的是：什么力量维持着这种制度？因为这在动物界有些不同寻常。”

In some kinds of animal societies, your place in the dominance hierarchy can be explained by physical attributes like body size. But in other animals, dominance rank can be acquired through things like age or nepotism.

在某些动物社会中，你在权力等级中的地位可由体型等身体特征来决定。但在其他动物中，社会等级会通过年龄或裙带关系来获得。

Strauss and colleagues collected data about five generations of four groups of wild spotted hyenas in Kenya that they observed over a 27-year period. And the researchers saw multiple instances in which a smaller hyena came to dominate a larger one. They've even seen severely wounded hyenas become dominant to healthy ones. The results are in the journal Proceedings of the National Academy of Sciences.

斯特劳斯和同事对肯尼亚四组野生斑点鬣狗的五代进行了27年的观察，并收集了数据。研究人员观察到了许多小鬣狗统治大鬣狗的案例。他们甚至看到了严重受伤的鬣狗成为健康鬣狗主宰的情况。研究结果发表在《美国国家科学院院刊》上。

Given those examples, it would seem that rank in spotted hyenas is fairly arbitrary. But it turns out that what researchers call "rank reversals" happen only rarely in this species—just 14 percent of the time. So how does it stay so stable over time?

从这些例子来看，斑点鬣狗的等级排列似乎相当随意。但事实证明，研究人员所说的“等级逆转”现象在斑点鬣狗中很少发生——只有14%的几率。那这种制度是如何随时间保持稳定的呢？

"They're systematically related to the coalitionary support that we observed...So females who had stronger coalitions with their top allies were more likely to increase their social rank."

“这些等级排列与我们观察到的联盟支持有系统联系……因此，与上层联盟关系更强的雌性，更可能提升自已的社会地位。”

Spotted hyenas could only climb the social ladder if they were able to maintain a strong alliance.

斑点鬣狗只有维持强大的联盟才能登上更高的社会等级。

"The social bonds of these animals are really very fundamental in establishing the structure of their societies."

“这些动物的社会联系对于建立它们的社会结构来说非常重要。”

In other words, the strength of relationships is what puts one hyena in its group's spotlight. 

换句话说，正是这种强大的关系让一只鬣狗成为了团队的焦点。

Thanks for listening for Scientific American — 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。