Jane C. Hu

雪后的山坡上，烏鴉像孩子一樣滑雪嬉戲，玩得不亦樂乎，這樣的一幕總會(huì)讓人感到驚奇。其實(shí)，很多動(dòng)物都頗有“娛樂精神”，比如袋鼠會(huì)拳擊，狐貍會(huì)蹦床，章魚會(huì)玩玩具，魚兒會(huì)相互追逐和跳躍……那么問題來了：對(duì)于動(dòng)物們來說，這些行為真的只是玩耍那么簡單嗎？科學(xué)家們好像發(fā)現(xiàn)了其他的答案……

Perched on the edge of a snowy slope, the youngster drops a small, makeshift sled at his feet.1. perch： 棲息；slope： 斜面，斜坡；makeshift： 臨時(shí)的，湊合的；sled： 雪橇。He steps onto it and glides down the incline,2. glide： 滑行；incline： 斜面。struggling to keep his balance. When the sled slows to a stop, he picks it up and trudges back up to the top for another go.3. trudge： 跋涉，步履艱難地走；go： n. 嘗試。Again and again he swoops4. swoop： 猛撲，俯沖。down the slope.

This could be a scene from any child’s snow day, but it’s also a description of a sledding crow who happened to get captured on camera.Even if you remind yourself that we humans are prone to misleading ourselves by anthropomorphizing other animals, it’s hard not to see the crow as playful.5. 即便你提醒自己說人類很容易將其他動(dòng)物人格化，從而擾亂自己的判斷，但這只烏鴉確實(shí)是在嬉戲，很難視為其他。be prone to： 易于……，有……的傾向；anthropomorphize： 人格化，賦予人性；playful： 頑皮的，愛嬉戲的。Without additional context, it’s hard to know what the crow’s really up to6. be up to： 從事，忙于。, but the crow does do a couple things that scientists would identify as play: His actions appear voluntary, yet pointless—there is no obvious function or bene fit to what he’s doing—and he repeats the action several times.

As anyone who has accidentally spent hours playing Candy Crush7. Candy Crush： 糖果粉碎傳奇，一款消除類手機(jī)休閑游戲。knows, play is fun, but also costly. It takes up time that could be spent doing something productive, or, even worse, it can even be dangerous:Hundreds of people are seriously injured in snowboarding8. snowboarding： 滑板滑雪運(yùn)動(dòng)。or skiing accidents every year. Yet play is surprisingly common in the animal kingdom. Kangaroos box for fun, octopuses play with toys, foxes jump on trampolines, fish jump and chase.9. kangaroo： 袋鼠；box： v. 拳擊；octopus： 章魚；trampoline： 蹦床。Even wasps10. wasp： 黃蜂。have shown evidence of play fighting.

Given the costs, scientists reason that there must be some evolutionary bene fit or purpose associated with play.11. reason： v. 推論；evolutionary： 進(jìn)化的，發(fā)展的。One theory is that play prepares animals for adulthood. In humans, pretend play12. pretend play： 假裝游戲，是學(xué)前兒童的主要游戲類型，比如過家家。is a vital stage in development—it helps develop imagination and gives children practice with taking other people’s perspectives. Likewise, it seems like play fights could prepare animals for con flict in adulthood,and that running and jumping could develop strength, endurance, and coordination for hunting or fleeing predators.13. endurance： 忍耐力；coordination：協(xié)調(diào)； flee： 逃離；predator： 捕食者。

But scientists have struggled to find any direct links between play and later preparedness. Zoologist Lynda Sharpe ventured into the Kalahari Desert to study young meerkats’ play behavior.14. zoologist： 動(dòng)物學(xué)家；venture into： 冒險(xiǎn)進(jìn)入；Kalahari Desert：喀拉哈里沙漠，位于非洲南部；meerkat： 貓鼬，產(chǎn)于喀拉哈里沙漠，是一種小型、花面的哺乳動(dòng)物。She theorized that if play helped hone15. hone： 磨練，訓(xùn)練。adult skills, meerkats who play fought more would win more often in fights as adults, but she found that this was not the case. Another study with kittens found the same thing: play did not correlate with success in adult skills, like catching mice.16. kitten： 小貓；correlate with：與……有關(guān)。What scientists have found is that play is sometimes related to general positive outcomes in adulthood; for instance, playful rats are less likely to develop Alzheimer’s17. Alzheimer’s： 等于Alzheimer’s disease，老年癡呆癥。, and bears who play as infants are more likely to live past their first year. But just how play could improve health is still mysterious. It might even be that engaging in play is a sign of a health rather than a cause of it.

If play doesn’t improve skills later on, perhaps it serves another purpose. Another theory scientists have considered is that play helps build social bonds or decrease aggression in the group. But though this explanation makes some intuitive sense,there’s little research to back it up.18. intuitive： 直覺的；back up： 支持。Sharpe’s meerkat studies concluded that meerkats that played were no less aggressive, and that meerkats that played with one another were no more likely to groom one another, a sign of social bonding.19. 夏普對(duì)于貓 的研究表明，喜歡玩耍的貓 仍然具有攻擊性，而與同伴一起玩耍的貓 也不可能為對(duì)方做一些如梳毛這種能體現(xiàn)社會(huì)聯(lián)系的事。no less： 仍然；groom： 為……梳毛。A study with wallabies20. wallaby： 小袋鼠。also found no relationship between play and social bonds. Plus, not all play is social—many animals, like the sledding crow, play alone.

Then there’s the possibility that play can moderate21. moderate： 減輕。stress.Humans feel the need to blow off steam after a long week, and it seems that the proverb“all work and no play makes Jack a dull boy”may apply to animals,too—play-deprived rats become aggressive,for example.22. 人類在度過漫長一周后需要發(fā)泄，“只會(huì)學(xué)習(xí)不會(huì)玩，聰明的孩子也變傻”這句諺語在動(dòng)物身上好像也適用，比如很少玩耍的老鼠會(huì)變得好斗。blow off steam：發(fā)脾氣，發(fā)泄；play-deprived： 缺少游戲的，很少玩耍的。Wrestling and play fights activate the same neural pathways used in real fights,23. wrestling： 摔跤，格斗；neural pathway：神經(jīng)通路。so play could train animals to deal with stressful situations. Conversely, when animals experience too much stress, play is often one of the first luxuries to go. An animal that is exhausted or starving must focus all resources on survival.24. exhausted： 筋疲力盡的；starving： 饑餓的。

To some extent, human play comes at the expense of animals’play. As humans urbanize25. urbanize： 都市化。animals’ natural environments, we take the land for our own purposes; what used to be animals’playgrounds are now our playgrounds, streets, and buildings.Playing squirrels are killed by cars when they chase each other onto roads, and kangaroos have taken to holding their boxing matches on suburban thoroughfares.26. suburban： 郊區(qū)的，城郊的；thoroughfare：大道，大街。Many animals in disrupted habitats become more stressed as they clamor to find homes and food,27. disrupted： 被破壞的，被中斷的；clamor：叫囂，喧嚷。which leaves less time and energy for play.

On the other hand, by posing new challenges for animals,urbanization also increases cognitive flexibility28. cognitive flexibility： 認(rèn)知靈活性。and brain size of urban animals. The demands of an urban life require ingenuity, and animals that seek out new niches in the environment are more likely to survive.29. ingenuity： 心靈手巧，足智多謀；niche： 生態(tài)位。If creativity is a signal of fitness, then our sledding crow friend will do just fine for himself in the city.