Guppies exposed to predators tend to aggregate into smaller, more tightly knit groups, which may allow them to coordinate their predator avoidance strategies. Jason G. Goldman reports.

据贾森·G·戈德曼（Jason G. Goldman）报道，遭遇天敌的孔雀鱼更倾向于聚集成更小更紧密的群体，以便合作躲避天敌。

撰文\播音：贾森·G·戈德曼（Jason G. Goldman）

翻译：杨枭

审校：丁可含

Humans aren't the only species that forms friendships. Lots of animals prefer to spend their time only with certain individuals.

人类并不是唯一有友情的物种。许多动物都更喜欢与同类个体待在一起。

"It's all very well showing that you do get social relationships and social bonds forming, but why on earth would you form them in the first place?"

“这显示出你拥有良好的社会关系和社会纽带，但是究竟为什么你会把这种关系放在第一位呢？”

University of Exeter animal behavior researcher Rob Heathcote. He and his team wanted to find out what benefit animals derive from close social relationships. To do it, they set out for the Caribbean island of Trinidad, home of a small freshwater fish called the Trinidadian guppy.

罗布·希思科特（Rob Heathcote）是埃克塞特大学的动物行为研究员。 他和他的团队想知道动物从亲密社会关系中会获得什么好处。为此，他们动身前往加勒比的特立尼达岛，那里是淡水鱼特立尼达孔雀鱼的家园。

"These guppies live in environments that have tons of predators around, so basically it really sucks to be a guppy. In some places they live, you'll be watching these shoals of guppies and a predator is attacking them every twenty or thirty seconds or so."

“这些孔雀鱼被天敌包围，因此在这做一只孔雀鱼真是糟透了。在一些它们生存的地方，你能看到鱼群大约每二三十秒就被攻击一次。”

One common idea is that such animals form social groups to reduce the risk of being gobbled up. But Heathcote wanted to see whether the benefits of social living might come from the strength of individual social relationships rather than simple safety in numbers.

通常想法是这些动物形成社群，以减少被吞食的风险。但希思科特希望看到社群生活的好处是否来自个体社群关系的力量，而不是简单的数量上的安全。

The researchers caught 240 female Trinidadian guppies and divided them into groups of fifteen, each group in its own small pool. While some of the fish were left alone, others were exposed to what looked like a predator—a doll version of a guppy-eating fish called a pike cichlid.

研究人员捕捉了240条雌性特立尼达孔雀鱼并把它们分成15组，每组单独置于一个小池塘。其中一些鱼中放入一个“天敌”——假的棘鲷。

Those guppies exposed to the ersatz predator were more likely to establish stronger social bonds. But the groups formed by those guppies were on average smaller than the groups formed by the fish that were not exposed to predators. [Robert J. P. Heathcote et al., Fear of predation drives stable and differentiated social relationships in guppies, in Scientific Reports]

那些暴露在天敌下的群体更可能建立更强的社会纽带。但相比于没有天敌的鱼群，这些鱼群普遍更小。

Heathcote thinks that the tighter-knit friendships that come from small groups allow guppies to more effectively cooperate in their predator avoidance activities.

希思科特认为，来自小团体的更紧密的友谊使得孔雀鱼在躲避天敌时的合作更有效。

“You can either hang out with a load of guppies, and every time these predators attack, you're unlikely to be the one that gets eaten. But obviously the first thing that happens when you form a big shoal is that this attracts every single predator in the vicinity… The alternative is you can be inconspicuous in a small social groups of three [or] four individuals. Everyone's kind of looking out for each other, they've got each other's back."

“你可以选择成为一大群鱼的一员，每次天敌袭击时，你都更可能幸存。但显而易见的是当你们形成一个巨大的鱼群，这会吸引周围的各色天敌。另一种选择，你可以加入一个三四只鱼组成的不起眼的小团体。彼此留心提防周围，成为彼此的后盾。”

So spending time with a few close friends could outweigh the benefits of blending in with the crowd, particularly in dangerous situations.

因此，花时间与几个亲密朋友在一起要比融入大群体更有益，特别是遇到危险时。

"Friendship," said Winnie the Pooh writer A. A. Milne through his character Christopher Robin, "is a very comforting thing to have." Especially when there's a big scary fish trying to eat you.

小熊维尼的作者A· A·米尔恩（A. A. Milne）通过他的角色克里斯托弗·罗宾（Christopher Robin）说，“拥有友谊令人欣慰。”特别是当有一个大的可怕的鱼试图吃你时。