The word brood in ornithology ( much like fish and insects ) three meanings:
In fish and in everyday language dominated the second meaning.
Nest and brood duration
After mating, the female lays in most species the fertilized eggs within a few days to a few weeks. In songbirds, the nest has an average of five to eight eggs but there are also species with only two or with more than 20 eggs.
In reptiles, the clutch size is comparable, but the number of eggs varies considerably with the fish and can range up to several hundred.
The incubation period of different bird species and genera may be between about ten days and three months.
Breeding and breeding behavior in parakeets
The Rose-ringed Parakeet takes approximately 23 days for his brood. During this period, he lays three to five eggs. Mostly, the female lays the eggs at intervals of about five days. Since necked Parakeets Dauerbebrüter are the breeding is incubated from the very first day. The first four weeks to spend the babies in the nest or nest box. Are they old enough to look out the entrance hole, the tap also involved in their rearing.
This is done by feeding the hen with a lot of protein-rich foods, they can be fed from the tap. With about five weeks, they fly from and be supported by food addition by the adult birds.
When budgie the female lays her eggs at intervals of about two days and broods from the very first. After three weeks, the eggs hatch also at intervals of two days. The feeding is done by the hen. The first four weeks to spend the babies in the nest or nest box. Also with about five weeks fly from the pups. With the delivery of the pups you should wait about two weeks, as they are still fed.
Breeding in the domestic fowl
From April / May puts the hen their 13 to 15 eggs at a distance of one to two days. Within about three to four weeks, she fills the nest and then begins with the breeding, by leaving the nest only once or twice a day to take food and water and to empty.
Since the development of the chick in the egg begins with the permanent heat, which emits the hen with her body, all the chicks hatch after 21 days almost simultaneously within 24 hours with a slip weight of 35 to 45 grams.
The breeding behavior is innate, even laying hens from battery cages to show it when they get the opportunity to build a nest to fill it and to brood.
The chick rearing the sole responsibility of the female chicken until its independence leads the chicks to feeding grounds, protected and warm.
Breeding in other birds
Laying intervals, and the duration of incubation may be less by about half of other avian species, as well as three to four times longer. However, they do not depend only slightly on the size of the animals, the clutch size.
In most bird species in Europe, the incubation period is two to four weeks. In the middle of this time frame is, interestingly, is the heavy, flightless during the moult great bustard with her two to three eggs. Also, the partridge incubated his nest ( about 20 eggs) three weeks. In the majority of songbirds there are about two weeks.
Parental care is - as with fish - often taken jointly by females and males.
Very different are the conditions for the large ratites. Some let the eggs hatch from the sun, others take over the males. The Nandu males, for example, mates, although with several females, worried but then only the business of breeding and rearing. The females pull off and still mate with other males.