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
設(shè)想這樣一個(gè)可怕的場(chǎng)景：你和家人遭受圍捕，你被迫目睹長(zhǎng)輩被殺，這會(huì)對(duì)你產(chǎn)生怎樣的影響？毫無(wú)疑問(wèn)，你嚇壞了。你可能會(huì)在之后的很長(zhǎng)一段時(shí)間內(nèi)都深感不安，或許這種感覺(jué)會(huì)持續(xù)一生。
常規(guī)獵殺
對(duì)于除人以外的一些生物而言，這種可怕的場(chǎng)景是十分常見(jiàn)的。比如幾十年前，大象會(huì)經(jīng)常遭受屠殺，借此控制它們的種群數(shù)量。捕獵者會(huì)將整個(gè)大象家族趕入一個(gè)狹小的空間，并槍殺其中一些年老的大象。因?yàn)楣珗@管理員擔(dān)心大象數(shù)量的增多會(huì)超出園區(qū)的負(fù)載限度，所以這種獵殺大象的行為實(shí)際上是在幫助它們。
但是調(diào)查表明，那些在獵殺中幸存下來(lái)的大象常常會(huì)深感不安。一項(xiàng)研究顯示，這些幸存的大象在社交和其他行為方面會(huì)出現(xiàn)嚴(yán)重的問(wèn)題。例如，一群失去親人的雄性大象在近十年中殺死了一百多頭犀牛。這是極端反常的行為。
失去長(zhǎng)輩即失去經(jīng)驗(yàn)
另一項(xiàng)研究顯示，當(dāng)科學(xué)家在那些幸存下來(lái)大象附近的一輛吉普車中播放大象的叫聲時(shí)，它們的回應(yīng)十分混亂。它們顯得茫然無(wú)措，有時(shí)還會(huì)采取防御措施。這并不像它們?cè)谡Ｇ闆r下回應(yīng)外來(lái)客或是族群中地位更高的母象所表現(xiàn)出的那樣。
科學(xué)家推測(cè)這是因?yàn)榇笙笸ǔ?huì)從長(zhǎng)輩身上學(xué)到這些重要的行為。當(dāng)長(zhǎng)輩遭受屠殺或偷獵后，年幼的小象在面臨潛在威脅時(shí)會(huì)顯得不知所措。不知道怎樣保護(hù)自己的大象，其幸存機(jī)率便會(huì)降低，繁殖能力也會(huì)減弱。盡管如今屠殺大象的行為已經(jīng)消失，但非法狩獵仍會(huì)產(chǎn)生類似的效果。
【本譯文由普特網(wǎng)友 Nathanpark 提供】
PS：英國(guó)Sussex大學(xué)的KarenMc－Comb教授和他的肯尼亞同行對(duì)生活在肯尼亞國(guó)家公園中的多個(gè)大象家族進(jìn)行了研究。在第一個(gè)實(shí)驗(yàn)中，科學(xué)家向17個(gè)家族的大象展示了大象、野牛和河馬的尸骨，發(fā)現(xiàn)大象只對(duì)大象的尸骨感興趣，這能說(shuō)明大象能分辨出同類的尸骨，在辨認(rèn)過(guò)程中，它們不僅用鼻子嗅，偶爾還用腳輕輕觸摸。另一個(gè)實(shí)驗(yàn)是向19個(gè)家族的大象展示一塊大象頭骨、一塊象牙及一塊木頭。結(jié)果顯示，大象對(duì)象牙的興趣要遠(yuǎn)遠(yuǎn)超過(guò)形狀與顏色相似的木頭。第三個(gè)實(shí)驗(yàn)是讓三個(gè)剛剛失去頭象的大象家族成員在三具大象頭骨中辨認(rèn)自己的首領(lǐng)，大象雖然能辨認(rèn)出同類的頭骨，但實(shí)驗(yàn)顯示，它們還是無(wú)法辨別出自己親屬的尸骨。 科學(xué)家認(rèn)為，即便如此，大象對(duì)同類的尸骨和象牙所表現(xiàn)出的興趣表明，它們還是非常有可能去拜訪死去親屬的尸骨的。它們?yōu)槭裁磿?huì)這么做呢？科學(xué)家表示，大象和猩猩相似，都是非常特殊的群居動(dòng)物，大象的身體有非常復(fù)雜的結(jié)構(gòu)，大腦非常大，而且相對(duì)壽命較長(zhǎng)。它們向同類尸骨表述情感的這種行為，也許與它們特定的認(rèn)知能力及社會(huì)行為能力有關(guān)，大象是生活在由雌性組成的家族中的，家族成員的關(guān)系因此相對(duì)密切。 McComb教授表示：大象不僅身材龐大，而且具有很高的智慧，是一種具有高度觸知能力的動(dòng)物，因此大象能區(qū)分同類與異類的尸骨也就不足為奇了。但是，Mc－Comb教授同時(shí)強(qiáng)調(diào)，雖然大象對(duì)死去同類的頭骨很感興趣，在靠近尸骨時(shí)表現(xiàn)得很不安，而且從太陽(yáng)穴上還會(huì)流下一些分泌物，但目前的證據(jù)還是無(wú)法準(zhǔn)確地表明它們的這種行為就是哀悼。
