英语听力文摘 中年狼 Middle Aged Wolves
狼是群居性极高的物种。一群狼的数量大约在6到12只之间，在冬天寒冷的时候最多可到五十只以上，通常以家庭为单位的家庭狼由一对优势对偶领导，而以兄弟姐妹为一群的则以最强一头狼为领导。狼群有领域性，且通常也都是其活动范围，群内个体数量若增加，领域范围会缩小。幼狼成长后，会留在群内照顾弟妹，也可能继承群内优势地位，有的则会迁移出去(大多为雄狼)而还有一些情况下会出现迁徙狼，以百来头为一群，有来自不同家庭等级的各类狼，各个小团体原狼首领会成为头狼，头狼中最出众的则会成为狼王。狼的奔跑速度极快，可达五十五公里左右，持久性也很好。它们有能力以速度10公里/小时(六英里)长时间奔跑 , 并能以高达近65公里/小时速度( 45英里) 追猎冲刺。 如果是长跑，它的速度会超过猎豹。
狼在三岁的时候捕食能力最强。随着它年龄的增长它的这种能力亦会下降。
Picture an elk walking through the forest, looking for some berries to nibble.
Then, suddenly, a pack of wolves leaps from the bushes, surrounding the startled animal. The wolves close in. The elk looks for an escape route, but the predators tighten the circle.
The elk is a goner, right?
Maybe. But it depends partly on the age of the wolves.
According to one study, wolves’ hunting skills peak around age three, and then their hunting prowess starts to decline. By the time wolves reach old age, around the age of six, they’re no longer the same hunters they were as youngsters.Why?
Because unlike lions, tigers, and other large predators, the average wolf doesn’t have the bulk or attributes to take down large prey with a single blow.
Wolves rely more on athleticism and endurance to bag elk. And like most athletes, wolves’ physical abilities decline with age. Once their skills erode, wolves aren’t much good as hunters.
So older wolves are good for elk. The study found that the older the average wolf population in an area, the more elk there are still around.
When the wolf population skews younger, more elk bite the dust.
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