Free Dumbo! Zoos Are Bad for Elephants, Study Says

For animals living in the wild, nature plays for keeps. A life spent battling predators, famine, disease and the elements may be an independent one, but it can also be a very short one. That, at least, is the case zoos and wildlife parks often make when they contend that protectivecaptivity may be a boon for many animals, particularly species that are endangered or threatened. But when it comes to at least one big and beloved creature, a new study suggests that a zoo might be the least safe place in the world.

In a survey of 4,500 captive elephants worldwide, a team of researchers from the U.K., Canada and Kenya found that once you lock up the giant, space-loving beasts, their health suffers, their median life span plummets, and they quit breeding - the last things you would want for a creature you're ostensibly trying to help survive. "Whether or not it's valid to say zoos keep species alive depends on which species you're talking about," says animal-welfare scientist Georgia Mason of the University of Guelph in Ontario. "Many species do well. Elephants don't."

Of all the findings reported in the new paper, it's the life-span numbers that are the most shocking. Among African elephants, zoo-born females live a median of 16.9 years in zoos, while those in the wild make it to a wizened 56. Asian elephants, the more endangered of the two species, live 18.9 years in captivity and 41.7 in the wild. A few superannuated wild elephants have actually reached their 70s, and in Kenya, from 30% to 50% of the noncaptive population hits at least 50. "So far," says Mason, one of the authors of the new study, published in the journal Science, "we've got 300 African elephants in zoos in Europe, and no one's yet reached 50."

Worse, what's killing the elephants is often ills they would never encounter in the wild. Obesity, for one: cage any healthy animal, feed it well and forbid it to move around too much, and it's likely to get fat. Cardiovascular disease is commonly reported among elephants, which, as in humans, can be a direct result of too many calories and too little exercise. What's more, baby elephants born in captivity are noticeably chubbier from the start than those born in the wild. That may be a result of the mothers weighing too much, but whatever the reason, Mason worries that as in humans, overweight juveniles are overwhelmingly likelier to grow into overweight adults, with all the attendant health risks.

Herpes, improbably, is killing elephants too - at least the Asian species. Wild African elephants are often infected with a form of herpes virus that causes them little illness or discomfort, but when the two species were brought together in zoos, the virus jumped to the Asians and mutated into a lethal form. "Zoos have accidentally created this," says Mason. "It's killing Asian elephant adults, and it's a leading cause of the species' infant mortality."

Another reason the babies are dying is, tragically, the mothers. Infanticide is almost unheard of among wild elephants. Mothers invest two years in their pregnancies, they live in stable matriarchal groups, and females collectively care for the young. In captivity, mothers are often held in relative solitude, undergo stressful and painful births, and then simply kill the source of all that suffering. Some mothers, Mason says, may even turn to infanticide because they just don't know what the small, squirmy creature that suddenly appeared in front of them is. "Many females in zoos have never seen a calf," she says, "so they may not recognize it."

Zookeepers and policymakers who aren't moved by all this suffering might instead be convinced by the simple fact that it costs a fortune to keep elephants so miserable. In the past 10 years, zoos have spent or committed to spend about $500 million to build or upgrade enclosures designed to improve the lives of 250 animals - but nothing so far suggests that does much to improve captive elephants' health or longevity. In Kenya, on the other hand, the wildlife service has an annual budget of just $20 million to look after tens of thousands of elephants. What's more, while Asian elephants remain in jeopardy - with only about 60,000 of them left - cost-effective wildlife-protection programs have allowed the African elephant population to rebound to a robust 500,000. "African elephants are a conservation success story," says Mason. That's true enough of much of the free population; not so much for the detainees.

动物园对大象有害

对于野生动物来说，自然界适者生存，一个生命一生中都在同肉食动物，饥饿，疾病做斗争这些因素也许是一个孤立的个体，但是它也可能是很短暂的。至少，动物园和野生公园就是一个例子，当它们竞争时这种保护性的圈养对许多动物来说也许是一种恩赐。尤其是对那些频危物种。可是当涉及到至少一种大型和有爱心的动物时，有新的研究表明，世界上动物园也许是最安全的地方。

一队来自U.K...加拿大和肯尼亚的科研小组对世界上4500头圈养大象作调查。一旦你将这些大型，博爱的动物锁住，你就会发现它们的健康受到损害，平均寿命直线下降，它们放弃生育--就是你们表面上试图帮助生存，想要繁育物种的最后一件事。"不管动物园是否保存物种存活那要看你讨论的是哪种物种。"安大略省革尔夫大学动物福利学家Georgia Mason.说，许多物种也许适应得很好，但大象不行。

新文件报道了所有这些研究成果。其中最令人震惊的是寿命缩短的数字，非洲象中，动物园中出生的雌象平均只存活16.9岁.而那些生活在野外的大象却能活到56岁..亚洲象,更频危的两大物种这一,圈养的活18.9岁.野生的活41.7岁.有一些老迈的野生象实际上能活到70岁左右.在肯尼亚,30%到50%的非圈养象至少活到50岁或更多.Mason称,其中一个作家的新研究发表在科学杂志上,"我们获悉欧洲动物园有300头非洲象它们没有一个寿命能活到50.

更糟的是,什么是杀戮,大象在野外从没遇到的病,表面上,是为了一件事:圈养健康的象,喂它们好的.禁止它们四处走动过多,这样会容易变胖.

报告说,心脑血管疾病在象群中普遍存在,就象人类一样,是摄取太多的卡里路和运动少的直接结果.,并且,在圈养区的小象从一出生就比野外的小象格外的胖.这也许是母亲太重的原因.但是无论什么原因,Mason担心,这会象人类一样,超重的少年非常容易长成肥胖的成年人,并伴随着健康危险.

疱疹,这也不一定,也在杀害大象---至少正在杀害亚洲象,野生非洲象经常被一种疱疹病毒感染,所以它们很少得病或感觉不舒服,但是这两类一起放在动物园的时候 ,这种病毒就会找上亚洲象,并且会变异成一种致命的病毒.动物园偶然地创造了这一条件.Mason说,它是导致这一种类小象死亡的原因.

导致小象死亡的另一个原因有点悲剧性,那就是母亲.杀婴在野外象群中几乎没有听说过,母亲怀孕两年时间,它们生活在固定的女性象群中,雌性集体照顾幼崽.,在圈养区中,母亲经常处在一种相对孤立的情况下,经历充满紧张和痛苦的生产,然后简单的杀死所有这些痛苦的根源,Mason说,一些母亲杀害婴儿甚至仅仅是因为,它们不知道这些突然出现在面前的小小的蠕动的小东西是什么,一些生活在动物园的雌象从没见过小牛,她说,因此它们也许没有意识到这一点.

动物园管理者和决策者不会因这些苦难而感动,而是,被一些简单的事实说服,那就是他们花费了巨大的财富让大象生活悲惨.在过去的十年,动物园已经花费或者说为了提高250种动物的生活贡献了5亿美元建造,改良设计的围场.---但是到目前仍没有任何建议能提高圈养大象的健康和寿命.在肯尼亚.另一一方面,野生服务机构每年有2000万美元的财政预算用于照顾数以万计的大象.并且亚洲象仍然处于危险之中,仅存6万余头,有效的野生保护计划让非洲大象数量反弹到正常的50万头.非洲大象是一个保守的成功案例.Mason说,散养的大象数量确实是多了,但圈养的还不够多.
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