Social Spider Groups Need Bold and Shy Members
群居蜘蛛：我们需要大胆与谨慎的伙伴

Social spiders in artificially assembled groups of all bold or all shy members fared less well against predators than a group with some shy and some bold members.
在人为构成的群居蜘蛛中，由大胆和谨慎的个体共同构成的群体，面对捕食者的表现要强于仅由大胆或是谨慎的蜘蛛组成的群体。

播音/撰文 Jason G. Goldman
翻译 Meatle
审校 吴非

What has eight legs, eight eyes, and lives together with thousands of others like it? Arachnophobia sufferers do not want to hear the answer—which is, spiders that live in large social groups.
有什么东西有八只眼、八条腿，和成千上万的同伴生活在一起？蜘蛛恐惧症患者不想说话，并把这个问题扔给了我——群居蜘蛛。

It's pretty rare to find such group-living spiders. Of the 45,000 spider species we know about, only about 25 are social. These species weave massive webs and dwell in colonies of dozens, hundreds or even thousands of individual spiders.
这些群居的蜘蛛相当罕见。在已知的45 000种蜘蛛中，只有25种具有群居的习性。这些蜘蛛编织巨大的蜘蛛网、挖掘可供成百上千只蜘蛛居住的洞穴成为成百甚至上千只同类的。

"When we want to count the spiders inside the colony, what we do is, somebody rips apart the colony, basically, with their hands. We call it 'making it rain,' and then dozens or hundreds of spiders basically shower down on little silken lines like little parachuters." University of California Santa Barbara arachnologist Jonathan Pruitt.
“为了统计居住地中的蜘蛛的数量，我们用手撕开蜘蛛的洞穴，而后成千上百的小蜘蛛如同伞兵一样吐着丝线下降下来。我们称之为‘人工造雨’” 加州大学圣塔芭芭拉分校的节肢动物学家Jonathan Pruitt介绍道。

He and his students study social spiders in South Africa's Kalahari Desert.After counting and weighing hundreds of African social spiders, Pruitt and his team gave each spider a personality assessment—some are bold, others shy. They wanted to understand how the personality composition of a colony influences its interactions with predators, and how the colony behaved over time.
他和他的学生在南非的喀拉哈里沙漠(Kalahari Desert)研究群居蜘蛛。在对数百只非洲群居蜘蛛进行计数、称重之后，Pruitt和他的团队对每一只蜘蛛的个性进行了评估——其中一些是大胆的，另一些是谨慎的。他们想知道，在面对捕食者时，群居蜘蛛的性格组成会对它们的行为产生怎样的影响，不同的性格组成对于居住地的发展又有何影响。

So the researchers combined their spiders into artificial groupings. Some of the experimental colonies were composed only of bold spiders, others of shy ones, and some had the two personality types in equal proportion. Then the researchers introduced predators to the party.
因此，研究人员对蜘蛛进行了分组。部分群体仅由大胆或谨慎的蜘蛛组成，其余的由两种性格的蜘蛛等量组成。而后，研究人员将捕食者带了进来。

"The most voracious predator that they deal with is this pugnacious ant, Anoplolepis steingroveri, which is this horrible ant. If you dropped one of these social spiders onto the ground, it's identified in seconds. And so these ants rip it apart and then drag it over to their colony."
“在它们面对的捕食者中，最为贪婪的是一种学名为 Anoplolepis steingroveri 的蚂蚁。如果你把一只蜘蛛放在地上，这些凶残的掠食者会第一时间发现这只可怜的蜘蛛，并马上把它大卸八块，拖进巢穴享用自助大餐。”

Turned out that the mixed-personality colonies were best able to learn from the repeated threat of ant raids, and build defensive nests to ward off attackers. Both the all-bold and all-shy colonies were less able to get it together enough to create their defensive structures, presumably because of too many—or not enough—leaders. The results are in the journal Animal Behaviour. [Colin M. Wright, Carl N. Keiser, & Jonathan N. Pruitt. Colony personality composition alters colony-level plasticity and magnitude of defensive behaviour in a social spider.]
研究结果表明，由不同个性的个体混合而成的群体在一次次的蚂蚁侵袭中学习能力最强，它们能有效地架设防御设施以抵御敌人。而在其余两种情况下，群体都无法架设防御工事，这可能是因为群体中的领导者不是太多就是太少。这项研究发表在《动物行为》( Animal Behaviour)上。

"The cool thing about social spiders is we know that they have these personality differences, and we know that societies are organized along these individual differences in behavior—actually very similar to the way that human societies are organized in a lot of ways."
“这项研究有意思的是，我们知道了这些群居蜘蛛具有个性差异，而它们的群体也由不同性格的个体组成——这与人类社会的组成，有太多相似的地方。”