Precocial

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In biology, the species precocial is a species in which the young are relatively mature and move from birth or hatch. The opposite developmental strategy is called "altricial," in which the young are born or the hatch is helpless. These categories form a continuum, with no clear space between them. Pre-social species are usually nififugous, meaning they leave the nest shortly after birth or hatch.

Video Precocial

Characteristics

The range between precocial and altricial species is very broad in birds. Precursor birds hatch with eyes open and covered with fluffy hairs immediately replaced by adult type hair. This type of bird can also swim and run faster after hatching than younger youth, like a singer bird. Very early birds can be ready to leave the nest in a short time after hatching (eg 24 hours). Many precursor children are not independent in thermoregulation (the ability to regulate their own body temperature), and they depend on the parents present to reflect on them with body heat for a short time. Pre-social birds find their own food, sometimes with help or instructions from parents. Examples of precursor birds include domestic chickens, many species of ducks and geese, waders, rails, and hoatzins.

Precocity is found in many other animal groups. Examples of the most well known mammalian precocial families are ungulates, marmots, and most species of rabbits. This last example shows that precociality is not a very conservative characteristic, in the sense of evolution, because the closely related rabbit is very altrical.

Pre-social species usually have longer gestation or incubation periods than related altical species, and smaller litters or grips, since each offspring must be brought to a relatively advanced (and large) state before birth or hatching.

The printing phenomenon studied by Konrad Lorenz is a feature of prasocial birds.

Maps Precocial

Superprecociality

Very precocial species are called "superprecocial". An example is the Megapode bird, which has full flying feathers and which, in some species, can fly on the same day as they hatch from their eggs.

Another example is the Blue Wildebeest, whose calf can stand in an average of six minutes from birth and run in thirty minutes; they can run faster than hyenas in one day. Such behavior gives them an edge over other herbivorous species; they are 100 times more abundant in the Serengeti ecosystem than hartebeests, their closest taxonomic relatives. Hartebeest's bethe is not a wildebeest calf and takes up to thirty minutes or so before they stand, and for forty-five minutes before they can follow their mother for a short distance. They can not follow their mother until they are more than one week old.

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Etymology

The word "precocial" comes from the same root as precocious , implying in both cases of early maturity.

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Phylogeny

Precociality is considered ancestral to birds. Thus, altricial birds tend to be found in the most widely derived group. There is some evidence for precociality in Protobirds and Troodontids.

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See also

• Publish prematurely
• Parent's investment

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References

Foot Records

Notations

• Starck J.M., Ricklefs R.E. (1998). "Pattern Development: Altricial - Spectrum Precocial". Growth and Development of Avian . New York: Oxford University Press

Source of the article : Wikipedia