英語聽力文摘 動物真的會數(shù)數(shù)？
動物會數(shù)數(shù)?
Can animals count? People count easily, from the time we are little kids and learn our one-two-threes. But what about other species? Careful observations in the wild support the idea that some can.
The American coot is a duck-like North American bird. Sometimes a coot will try and sneak one of its eggs into a neighbor’s nest. Some coots recognize the deception, and roll the stranger’s egg out again. Others don’t catch on, and raise the stranger’s egg as their own.
Researcher Bruce Lyon at the University of California, Santa Cruz, and his team observed a series of coot nests for four seasons, noting which birds could spot a stranger’s eggs and which couldn’t. Then they compared how many eggs each kind laid.
Their finding? The coots that couldn’t tell when a stranger’s egg had been stuck into their nest laid that many fewer of their own–sneak one in, the coot lays one fewer.
Sneak two in, the coot lays two fewer. Coots that successfully spotted intruders knocked them out again and then laid the same number they normally would.
If the number of eggs laid were independent of how many the coot sees in its nest, coots that allow a stranger’s egg should wind up with one egg extra. But they don’t.
Lyon argues that, along with egg recognition, the coots must therefore be doing some version of “I see I have nine eggs here–time to stop laying now.” And that means coots count.
Other researchers aren’t convinced. But though the debate goes on, the case for animal counting just got stronger…by the weight of one coot.
動物會數(shù)數(shù)嗎?對于人來說，數(shù)數(shù)很簡單。當(dāng)我們還是小孩的時候就學(xué)會數(shù)數(shù)了。但是其它生物呢?通過在自然環(huán)境下的一些仔細觀察發(fā)現(xiàn)有的動物能數(shù)數(shù)。
美洲白骨頂是一種鳥，它們生活在北美并且長得像野鴨。有時白骨頂嘗試把自己的蛋偷偷放到相鄰巢穴中。有的白骨頂能識破詭計，把這個不明來路的蛋挑出來。其它白骨頂根本認不出，就把它當(dāng)作自己的后代撫養(yǎng)長大。
研究人員，加利福利亞大學(xué)的布里斯里昂，在圣克魯斯和他的團隊觀察了很多的白骨頂巢，并且是在不同 的季節(jié)。他們記錄下了哪些鳥能認出陌生的鳥蛋，哪些不能認出。然后他們比較了這些鳥各生了多少蛋。
結(jié)果呢?發(fā)現(xiàn)那些不能認出陌生蛋的鳥，它們巢穴里的陌生蛋越來越多，而自己的蛋越來越少。
多出兩個陌生蛋，它們就會少生兩個蛋。而那些認出闖入者的鳥則會將其趕走，然后生產(chǎn)通常相同數(shù)量的蛋。
如果生產(chǎn)蛋的數(shù)量與巢里蛋的數(shù)量是獨立的，那么白骨頂就會算上陌生蛋，不再生蛋?？墒撬麄兯鼈儾粫?/p>
里昂認為，有識別蛋能力，所以白骨頂可能在想“已經(jīng)有了九個蛋，可以停止產(chǎn)蛋了”。那就意味著它們能數(shù)數(shù)。
其他研究人員并不相信這一理論。雖然爭論還在繼續(xù)，但動物會數(shù)數(shù)的事例越來越靠譜，因為一只白骨頂。
