Broodiness

[1] Being broody has been defined as "Being in a state of readiness to brood eggs that is characterized by cessation of laying and by marked changes in behavior and physiology".

The females leave the nest after finishing laying to let the males incubate the eggs and take care of the young.

A small number of atypical birds such as Passeriformes of the genus Molothrus (cowbirds) do not become broody but lay their eggs in the nests of other species for incubation, known as brood parasitism.

[5] The crab-plover, (Dromas ardeola), which lives on the coasts and islands of the Indian Ocean, lets its eggs incubate primarily by the heat of the sun, and will leave its nest unattended, occasionally for days at a time.

[8] Removing eggs each day, out of the sight of the hens, helps avoid broodiness not only in domestic poultry but also in some wild species in captivity.

To help achieve this, there has been intense artificial selection for non-broodiness in commercial egg laying chickens and parent stock of poultry.

Breeds such as Cochin, Cornish and Silkie exhibit a tendency to broodiness, including brooding eggs from other species such as quails, pheasants, turkeys and geese.

There is common agreement that artificial selection for egg production succeeded in reducing the incidence of broody hens in chicken populations.

A specimen of the extinct Mongolian oviraptorid Citipati osmolskae was discovered in a chicken-like brooding position in 1993,[19] which may indicate that they had begun using an insulating layer of feathers to keep the eggs warm.

[21] Lungless salamanders in the family Plethodontidae lay a small number of eggs in a cluster among damp leaf litter.

The female salamander often broods the eggs and in the genus Ensatinas, she has been observed to coil around them and press her throat area against them, effectively massaging them with a mucous secretion.

Most commonly, the male patrols the pair's territory and repels intruders, while females fan water over the eggs, removing the infertile and leading the fry while foraging.

Mouthbrooding, also known as oral incubation, refers to the care given by some groups of animals to fertilized eggs or their offspring by holding them in the mouth of the parent for extended periods of time.

The motile larvae, after swimming out of the mouth, migrate down to the disk and become fixed there until they become little anemones, ready to move and feed independently.