Birth
Videos
Birth is the act or process of bearing or bringing forth offspring, also referred to in technical contexts as parturition. In mammals, the process is initiated by hormones which cause the muscular wal
Lambing: the mother licks the first lamb while giving birth to the second
An illustration of normal head-first presentation by the obstetrician William Smellie from about 1792. The membranes have ruptured and the cervix is fully dilated.
A cow giving birth
A kangaroo joey firmly attached to a nipple inside the pouch
Precocial species in birds and mammals are those in which the young are relatively mature and mobile from the moment of birth or hatching. They are normally nidifugous, meaning that they leave the nes
Birth
…walls of the uterus to contract, expelling the fetus at a developmental stage when it is ready to feed and breathe. In some species, the offspring is precocial and can move around almost immediately after birth but in others, it is altricial and completely dependent on parenting. In marsupials, the fetus is…
A young chick stands up. Chickens are precocial birds and can stand shortly after hatching.
Altricial young birds
California quail chick (Callipepla californica), a precocial chick
A foal and its mother, a precocial mammal.