True hibernation has only ever been documented in one bird, so far at least: the common poorwill in the U.S. Southwest.

至少到目前为止，只有一种鸟类有过真正冬眠的记录：美国西南部的北美小夜鹰。

And there's at least one truly hibernating bird: the common poorwill sleeps out winters in the deserts of North America.

且，至少有一种鸟类真的会冬眠：在北美沙漠的弱夜鹰会以睡眠方式渡过整个冬天。