Disturbed Elephants
Here’s a gruesome hypothetical: If you and your family were rounded up, and you were forced to watch as older relatives were killed, how would it affect you? Needless to say, you’d be horrified. You’d probably also be deeply disturbed for a long time afterwards. Maybe forever.
Regular Culling
For some non human species, that grisly scenario is all too common. For instance, up until a few decades ago elephant populations were regularly culled. That is, family groups were herded into a tight space so that hunters could shoot and kill the older individuals. The practice was actually meant to help elephants, because park officials worried they’d grow too numerous and overrun the area.
But research has shown that the surviving elephants are often deeply disturbed. One study found that elephants from a culled group had serious problems with social and other behaviors. For example, a group of orphaned male elephants killed more than one-hundred rhinoceroses over a decade — behavior that’s highly abnormal.
Lose Elders, Lose Educators
Another study found that culling survivors responded chaotically to elephant calls broadcast by scientists in a nearby jeep. The animals seemed at a loss — sometimes taking defensive measures, but not necessarily in response to calls from alien or more socially dominant females, as they normally would.
Scientists speculate that’s because elephants typically learn these important behaviors from their elders. And when those elders are culled or poached, the younger elephants may not learn how to respond to potential threats. Elephants that don’t know how to defend themselves have less chance of surviving and reproducing. Although culling is no longer practiced, poaching is. And it may have similar effects.
不安的大象
设想这样一个可怕的场景：你和家人遭受围捕，你被迫目睹长辈被杀，这会对你产生怎样的影响？毫无疑问，你吓坏了。你可能会在之后的很长一段时间内都深感不安，或许这种感觉会持续一生。
常规猎杀
对于除人以外的一些生物而言，这种可怕的场景是十分常见的。比如几十年前，大象会经常遭受屠杀，借此控制它们的种群数量。捕猎者会将整个大象家族赶入一个狭小的空间，并枪杀其中一些年老的大象。因为公园管理员担心大象数量的增多会超出园区的负载限度，所以这种猎杀大象的行为实际上是在帮助它们。
但是调查表明，那些在猎杀中幸存下来的大象常常会深感不安。一项研究显示，这些幸存的大象在社交和其他行为方面会出现严重的问题。例如，一群失去亲人的雄性大象在近十年中杀死了一百多头犀牛。这是极端反常的行为。
失去长辈即失去经验
另一项研究显示，当科学家在那些幸存下来大象附近的一辆吉普车中播放大象的叫声时，它们的回应十分混乱。它们显得茫然无措，有时还会采取防御措施。这并不像它们在正常情况下回应外来客或是族群中地位更高的母象所表现出的那样。
科学家推测这是因为大象通常会从长辈身上学到这些重要的行为。当长辈遭受屠杀或偷猎后，年幼的小象在面临潜在威胁时会显得不知所措。不知道怎样保护自己的大象，其幸存机率便会降低，繁殖能力也会减弱。尽管如今屠杀大象的行为已经消失，但非法狩猎仍会产生类似的效果。
【本译文由普特网友 Nathanpark 提供】
PS：英国Sussex大学的KarenMc－Comb教授和他的肯尼亚同行对生活在肯尼亚国家公园中的多个大象家族进行了研究。在第一个实验中，科学家向17个家族的大象展示了大象、野牛和河马的尸骨，发现大象只对大象的尸骨感兴趣，这能说明大象能分辨出同类的尸骨，在辨认过程中，它们不仅用鼻子嗅，偶尔还用脚轻轻触摸。另一个实验是向19个家族的大象展示一块大象头骨、一块象牙及一块木头。结果显示，大象对象牙的兴趣要远远超过形状与颜色相似的木头。第三个实验是让三个刚刚失去头象的大象家族成员在三具大象头骨中辨认自己的首领，大象虽然能辨认出同类的头骨，但实验显示，它们还是无法辨别出自己亲属的尸骨。 科学家认为，即便如此，大象对同类的尸骨和象牙所表现出的兴趣表明，它们还是非常有可能去拜访死去亲属的尸骨的。它们为什么会这么做呢？科学家表示，大象和猩猩相似，都是非常特殊的群居动物，大象的身体有非常复杂的结构，大脑非常大，而且相对寿命较长。它们向同类尸骨表述情感的这种行为，也许与它们特定的认知能力及社会行为能力有关，大象是生活在由雌性组成的家族中的，家族成员的关系因此相对密切。 McComb教授表示：大象不仅身材庞大，而且具有很高的智慧，是一种具有高度触知能力的动物，因此大象能区分同类与异类的尸骨也就不足为奇了。但是，Mc－Comb教授同时强调，虽然大象对死去同类的头骨很感兴趣，在靠近尸骨时表现得很不安，而且从太阳穴上还会流下一些分泌物，但目前的证据还是无法准确地表明它们的这种行为就是哀悼。
