照顾期
Mammalian neonates can be divided into three categories, namely precocial, altricial, and immature, mainly according to their establishment of successful thermoregulation. 摘要按照体温调节能力的发育情况，哺乳动物的生长发育可分为早成性、晚成性和未成熟性3类。
altricial birds. 晚成雏的鸟
altricial bird 留巢鸟
