第117期：一根毛也不能少！“pk”人类发际线和鸟类羽毛

我们是很在意发量的，普通的成年人头皮毛囊大概有 8 万–15 万个，可是全身绝大多数体毛退化了。早期的鸟类学家手工逐根数毛，发现了鸟类羽毛的秘密。曾经有一个规律，体型越大，单位体重羽毛越少。小天鹅站了出来打破了规律。以前全认为帝企鹅羽毛密度最高，新研究发现它正羽密度其实一般，可是算上基部副羽、绒羽，总羽量登顶鸟类冠军。潜水的白喉河乌全身是毛，红喉北蜂鸟的毛量为了飞行而妥协。

告别焦虑吧，朋友。毛发多少这些全是大自然安排的。

好“鹅”一身毛

“划水”的鸟 白喉河乌

会飞，毛少.....

参考文献

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