What is Precocial?
'''Precocial''' in biology is a [[development]]al [[strategy]]. It refers to [[species]] in which the young are relatively mature and mobile from the moment of [[birth]] or [[wikt:hatch|hatching]]. It applies mainly to [[mammal]]s and [[bird]]s. The opposite developmental strategy is called [[altricial]], where the young are born or hatched helpless. These two categories are at ends of a continuum. All degrees exist in birds and mammals. With the tiny eggs of [[invertebrate]]s, different strategies have evolved. Many use some kind of [[metamorphosis]], in which different stages of growth occupy different environmental [[niche]]s. == Checklist == A checklist is used to score a species between precocial and altricial. In each case, 'yes' means precocial: #[[Down]] or [[fur]] present? #Eyes open? #Mobile? #Feed themselves? #Parents present? == Birds == The contrast between the two extremes is seen most clearly in birds. Precocial species leave the [[nest]] shortly after birth or hatching. [[Megapode]]s are a family of birds found in [[Australasia]]. Their eggs are not [[incubate]]d by the parents. They are buried in [[compost]], covered with sand and left, though the males test the [[temperature]] of the heap and make small adjustments. The eggs, which have a large yolk, hatch with full wing feathers. The hatchlings can run and purse prey, and many species can fly on their first day.<ref>Starck J.M. & Sutter E. 2000. Patterns of growth and heterochrony in moundbuilders (Megapodiidae) and fowl (Phasianidae). ''J. Avian Biol''. '''31''', 527-547.</ref> These birds are super-precocial. At the other extreme are the most intelligent birds: the [[passerine]]s (the dominant group of birds, including [[crow]]s) and [[hawk]]s, [[owl]]s and [[parrot]]s. == Mammals == Mammals never feed themselves at first. Mother's milk is part of the 'contract' a mammal inherits. But there is a big difference between some new-born [[deer]] and [[antelope]]s, which can run within an hour or so of birth, and a baby [[marsupial]] which is