VOA常速英语2018--雪鸮：生活在北极的鸟类（在线收听）

From a bird’s eye view the vast Alaska tundra is nothing more than an endless flat surface symmetrical and seemingly uninhabited.However, a closer look shows that it is home to lots of busy creatures that live comfortably and the grass and pits filled with icy cold water.

从鸟瞰的角度看，广袤的阿拉斯加苔原不过是一个对称的、似乎无人居住的广阔平地。然而，仔细观察就会发现，这里居住着许多生活舒适的而又繁忙的生物，还有填满冰冷的水的草丛坑洼。

For lemmings, small fussy rodents, there is no place more comfortable than the Arctic tundra.Their presence ensured their well-being of other tundra inhabitants that eat them: owls, Arctic foxes, weasels, eagles, gulls and cranes.

对于旅鼠这种小而挑剔的啮齿类动物来说，没有比北极苔原更舒适的地方了。它们的存在确保了其他苔原栖息者的福祉，猫头鹰、北极狐、黄鼠狼、鹰、海鸥和鹤都以它们为食。

Wildlife researcher Denver Holt has been coming to Utqiagvik every summer for almost three decades gathering data on snowy owls.That means heading straight into the tundra on a four-wheeler.So this is the brown lemming and this is whose numbers fluctuate over time and in high years the snowy owls have a good year because they eat lemmings.Almost everything they eat is the brown lemming here.

近三十年来，野生动物研究人员丹佛·霍尔特每年夏天都会来到乌特恰维克，收集有关雪鸮的资料。这就意味着要开着四轮车直奔苔原。这是棕色的旅鼠，它们的数量随着时间的变化而波动，雪鸮数量达到峰值时，也就是年景好的时候，它们有大量的旅鼠吃。它们吃的几乎都是棕色的旅鼠。

Some are here with 24 hours of daylight—it is a bird watchers’ feast.They come from all over the world to observe the dozens of species that migrate here to breed during the short Arctic summer and to feast in the abundance of available food.But it is the snowy owl that rains in the tundra, and Barrow is the only place in the US where these magnificent birds nest regularly.But their numbers have fallen recently as has been the number of lemmings.And scientists are trying to understand why.

极昼时观察鸟类是鸟类观察者的盛宴。他们来自世界各地，来观察几十个物种，这些物种是在北极短暂的夏季到来时迁徙到这里繁殖并享用丰富的食物的。但是只有雪鸮降落在苔原上，而巴罗是美国唯一的有迁徙规律的鸟类筑巢的地方，很是壮观。但它们的数量最近有所下降，旅鼠的数量也有所下降。科学家们正在试图弄清原因。

We do nest-checks every three days.You see the chicks here... there’s five chicks and two eggs and the newest chick underneath here is just hatching out right as we speak.So there is lemmings here... so good side you have...seven eggs or five chicks or two eggs right now.And you have lemmings...that’s a nest indicating that lemmings are reserved...somewhat abundant.

我们每三天查一次鸟巢。你看所有的雏鸟都在这儿...有五只雏鸟和两个蛋，下面的刚出生的雏鸟就在我们说话的当儿刚刚孵出来的。这里有旅鼠，你来的很是时候，现在有七个蛋…五只雏鸟，两个蛋。还有旅鼠...这一个巢表明是有旅鼠的...量有点儿大。

But a good head start doesn’t guarantee survival.These chicks will not be able to fly for months and will be easy prey for bigger predators.So monitoring mortality is part of the job and a very difficult part.

但是孵化出来并不能保证所有的都能存活下来。这些雏鸟几个月都不能飞行，很容易成为大型捕食者的猎物。所以监测死亡率是我们工作的一部分，也是非常困难的一部分。

It does become personal... I hate to say that.You try to be an objective researcher but in the end you become very fond of the species that you work with.If predators get in and kill chicks or if chicks die because the reasons sometimes unknown, I feel bad, but I don’t do anything about it.If I know a chick is losing weight, is gonna die, it bothers me but it’s not my job to save them and make more of them.It’s my job to document their life.

这就得看个体了...我不喜欢这样说。你开始是要成为一个客观的研究者的，但最终你会喜欢上所研究的物种。如果捕食者侵入并吃掉雏鸟，或者雏鸟莫名其妙死亡，我会很难过，但我却不采取任何行动。我知道一只雏鸟日渐消瘦，直至死亡，我会很不安，但我的工作不是拯救它们并使它们数量更多。记录它们的生活才是我的工作。

Stepping back and watching the natural selection do its job at all time is the hardest job of all.

总是退后一步，观察自然选择起作用，是最困难的工作。