Scientists set up an avian casino in which pigeons could place their bets on one of two symbols. Peck at symbol 1 and you get three food pellets. Never more， never less. Symbol 2 was the wildcard. Choose that one and 20 percent of the time， you’ll hit the jackpot： 10 food pellets. The rest of the time you’ll get nothing. But the lure of the big win was too hard to resist： pigeons chose to gamble more than 80 percent of the time， even though， on average， that path paid out fewer pellets.
Perhaps it’s the joy of a pleasant surprise. Because even for a literal bird brain， hitting the lottery is a hoot.
Vocabulary 词汇
Blackjack ["bl？kd？？k] n. 扑克牌的二十一点；
vt. 以棒打
gamble ["ɡ？mbl] vi. 赌博，投机；
vt. 赌博，孤注一掷；
n. 冒险，赌博
critters ["krit？] n. 生物，小动物（critter的复数形式）
casino [k？"si：n？u] n. 娱乐场，俱乐部，赌场
pellets ["pelits] 芯块，小球（pellet的复数）；
v. 使形成小球（pellet的第三人称单数）
Practice
What do you think of pigeons’ action？
译文
二十一点、吃角子老虎机和德州扑克——人们都喜欢赌博，但喜欢赌博的不只是人。研究显示，鸽子也会为了获得更大的回报而放弃一些近在眼前的好处。
觅食理论告诉我们，动物会贯彻所谓的“一鸟在手胜于双鸟在林”这种谚语，面对食物时更是坚定不移。吃东西是生存的关键，因此聪明的动物不会冒不必要的险。但是新的研究表示鸽子并不总会谨慎行事。
科学家们搭建了一个空中赌场，让鸽子们在两个标志之间“下赌注”。在标志1处，鸽子可以啄食三粒食物，就三颗，不多也不少。而标志2处是个未知领域。如果选择了这个地方，鸽子就有20%的可能中头奖：得到十粒食物。其余80%的情况是不会得到任何东西。但是头奖的诱惑太难抵挡了：80%的情况下鸽子都会选择赌一把，虽然这个选择平均来讲得到的食物更少。
可能这是个让人感到愉悦的惊喜。因为就算在鸟儿那毫无想象力的脑袋瓜里面，赌博都是一个诱人的犯罪。
练习
你是怎么看待鸽子的冒险行为的？
05 Why a Cat Purrs 为什么猫会打呼噜
No one knows for sure why a domestic cat purrs， but many people interpret the sound as one of contentment. Our understanding of why a domestic cat purrs is becoming more complete； most scientists agree that the larynx （voice box）， laryngeal muscles， and a neural oscillator are involved.
Kittens learn how to purr when they are a couple of days old. Vets suggest that this purring tells “Mom” that “I am okay” and that “I am here”. It also indicates a bonding mechanism between kitten and mother.
As the kitten grows into adulthood， purring continues. Many suggest a cat purrs from contentment and pleasure. But a cat also purrs when it is injured and in pain. Dr. Elizabeth Von Muggenthaler， a famous biologist， has suggested that the purr， with its low frequency vibrations， is a “natural healing mechanism”. Purring may be linked to the strengthening and repairing of bones， relief of pain， and wound healing.
Purring is a unique vocal feature in the domestic cat. However， other species in the Felidae family also purr： bobcat， cheetah， Eurasian lynx， puma， and wild cat. Although some big cats like lions exhibit a purr-like sound， studies show that the Patherinae subfamily： lion， tiger， leopard， jaguar， snow leopard， and clouded leopard do not exhibit true purring.
What makes the purr distinctive from other cat vocalizations is that it is produced during the entire respiratory cycle （inhaling and exhaling）. Other vocalizations such as the “meow” are limited to the expiration of the breath.
Vocabulary 词汇
domestic [d？u"mestik] adj. 国内的，家庭的，驯养的；
n. 佣人，国货
oscillator ["？sileit？] n. [电子] 振荡器，摆动物，动摇的人
mechanism ["mek？niz？m] n. 机械装置，技巧，原理，途径，进程
vibration [vai"brei？？n] n. 振动，犹豫，心灵感应
mechanism ["mek？niz？m] n. 机制，原理，途径，进程
respiratory ["resp？r？t？ri， ri"spai？-] adj. 呼吸的
vocalizations ["v？uk？laizei？？ns， -li"z-] n. 发声，发音，发声法
Practice
Write yes if the sentence is true. Write no if the sentence is not true.
1．Cats’ purrs are concerned with the larynx， laryngeal muscles， and a neural oscillator.
2．Kittens’ purrs indicate a bonding mechanism between them and mother．
3．Cat maybe purrs when it is injured and in pain．
4．Purring is a unique vocal feature in the cat．
5．Lion do not exhibit true purring．
译文
没有人确切知道为何家猫会发出呼噜声，但很多人都把这种声音理解成是一种心满意足的表现。我们人类对于家猫为何发呼噜声的认识正日趋完善，大多数科学家都赞成该现象与喉、喉部肌肉和神经元振荡器有关。
幼猫在几天大的时候就学会发出呼噜声了。兽医们认为这是在告诉猫妈妈“我挺好的”和“我在这儿呢”之类的信息。发呼噜声也说明幼猫和猫妈妈之间存在着一种亲密的心理感应关系。
幼猫成长为成年猫的过程中，会继续发出呼噜声。很多人都认为猫是因为满足和愉快才发出这种声音的。但是，猫受了伤或处于疼痛中时，也会发出呼噜声。著名的生物学家伊丽莎白·冯·穆根塔勒提出，呼噜声连同其低频振动是一种“天然的治疗机制”。发出呼噜声或许与骨骼的加固与矫正，减轻疼痛以及愈合伤口有着某种联系。
呼噜声是家猫所特有的发音特征。然而，在猫科动物中，其他种类也会发出呼噜声，如短尾猫、猎豹、欧亚猞猁、美洲狮和野猫。尽管像狮子一类的大型猫科动物也会发出呼噜般的声音，研究却表明豹亚科动物，比如狮子、老虎、美洲豹、美洲虎、雪豹及云豹，并不能发出真正的呼噜声。
呼噜声与猫科动物的其他发声的不同之处在于，前者产生于整个呼吸循环（包括吸气和呼气）过程中，而像“喵”这样的其他发声现象仅在呼气的时候产生。
练习
判断正误：
1．猫咪的呼噜声与喉、喉部肌肉和神经元振荡器有关。
2．小猫的呼噜声说明幼猫和猫妈妈之间存在着一种亲密的心理感应关系。
3．猫受了伤或处于疼痛中时也许会发出呼噜声。
4．只有猫会发出呼噜声。
5．狮子不能发出真正的呼噜声。
1．yes 2．yes 3．yes 4．no 5．yes
06 Bees Help Track Criminals 蜜蜂帮忙抓捕罪犯
Unless you’re talking about killer bees， it’s hard to imagine a situation in which “killers” and “bees” would be related. But it turns out that scientists are using the same mathematical model to describe the behavior of both bumblebees and human serial killers.
The method， called geographic profiling， was developed by a detective who was trying to predict where serial killers might live based on where they commit their crimes. Believe it or not， murderers operate fairly close to home. But not too close. They maintain a kind of kill-free “buffer zone” around their actual digs.
A similar pattern of activity seems to hold true for bumblebees—when they’re foraging for food. Bees tend to avoid stopping at flowers too close to home， perhaps to reduce the risk of drawing predators， parasites or nosy scientists to the nest. And working with the former detective， scientists in the U.K. found that geographic profiling allowed them to locate the entrance to a hive based on mapping which flowers the bees visit. Repeating such experiments， with bees or other foraging critters， could help hone the model for catching criminals.
Vocabulary 词汇
bumblebees ["b？mblbi：] n. [昆] 大黄蜂
serial ["si？ri？l， "si：r-] adj. 连续的，连载的，分期偿还的；
n. 连载小说，期刊
predict [pri"dikt] vt. 预报，预知；
vi. 做出预言，作预报
crimes crime [kraim] 的复数形式） n. 犯罪
predators ["pred？t？] n. [动] 捕食者；[动] 食肉动物，掠夺者
geographic [d？i？"gr？fik] adj. 地理的，地理学的
Practice
Why can the bees help track criminals？
译文
除非你是在谈论能致人于死命的蜜蜂，否则你很难想象把“杀手”和“蜜蜂”联系在一起。但是科学家们能用相同的数学模型来描述大黄蜂和连环杀手的行为。
这种名叫“地理画像”的方法是由一个侦探开发出来的，该侦探试图根据罪犯实施犯罪的地点来预测连环杀手的住所。信不信由你，凶手行凶的地方其实离他的住所不远，但也不是很近。他们在其巢穴附近保持一定的无犯罪现场的“缓冲区”。
大黄蜂觅食时候的活动情景与此类似。蜜蜂倾向于不在离家近的花朵上停留，它们此举或许是想避免招惹其他捕食者、寄生虫或者“爱管闲事”的科学家们到它们的蜂巢。英国科学家们和前面提及的侦探合作，发现根据蜜蜂采过的不同花所得到的地理画像能帮助他们找到蜂巢的入口。利用蜜蜂或者其他的动物重复这样的实验，或许可以进一步提高模型的准确性，从而帮助抓捕罪犯。
练习
为什么蜜蜂能帮助抓捕罪犯？
The bumblebees and human serial killers have similar pattern of behavior．
07 Are Cats as Detestable as Rats 猫和老鼠一样坏吗？
