The captive birds were trained to weigh themselves on electronic balances.

笼鸟被训练得自行在电子秤上称体重。

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It also makes sense that they would have fewer alarm calls, because captive birds don't experience the threat of predation. The study was published in the journal Animal Behaviour. Ann m.

他们也有在野外非常酷的领土广播呼叫[野生领土呼叫]那不是在圈养乌鸦中能发现的。

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Experiments with captive Humboldt Penguins at Brookfield Zoo proved, for the first time, that the birds use scent to discriminate between close relatives and strangers.

研究人员对美国布鲁克菲尔德动物园圈养的汉波德企鹅进行试验，首次发现企鹅可以嗅出陌生者与亲戚。

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The trust said money raised would be used to protect wild nests, feed underweight wild chicks, increase nest site availability and release captive-raised birds.

BBC: Race starts in west Cornwall to save rare wild macaws

Tests on captive vultures fed carcass flesh traced with the drug produced symptoms that were strikingly similar to those witnessed in sick birds in the wild.

BBC: NEWS | Science/Nature | Bird groups hopeful on vultures