Budgerigar

The budgerigar (Melopsittacus undulatus) also known as the common pet parakeet or shell parakeet and informally nicknamed the budgie, is a small, long-tailed, seed-eating parrot. Budgerigars are the only species in the Australian genus Melopsittacus, and are found wild throughout the drier parts of Australia where the species has survived harsh inland conditions for the last five million years Budgerigars are naturally green and yellow with black, scalloped markings on the nape, back, and wings, but have been bred in captivity with colouring in blues, whites, yellows, greys, and even with small crests. Budgerigars are popular pets around the world due to their small size, low cost, and ability to mimic human speech. The origin of the budgerigar's name is unclear. The species was first recorded in 1805, and today is the third most popular pet in the world, after the domesticated dog and cat.
The budgerigar is closely related to the lories and the fig parrots. They are one of the parakeet species, a non-taxonomical term that refers to any of a number of small parrots with long, flat and tapered tails. In both captivity and the wild, budgerigars breed opportunistically and in pairs.

Breeding

Breeding in the wild generally takes place between June and September in northern Australia and between August and January in the south, although budgerigars are opportunistic breeders and respond to rains when grass seeds become most abundant. They show signs of affection to their flockmates by preening or feeding one another. Budgerigars feed one another by eating the seeds themselves, and then regurgitating it into their flockmate's mouth. Populations in some areas have increased as a result of increased water availability at farms. Nests are made in holes in trees, fence posts, or logs lying on the ground; the four to six eggs are incubated for 18–21 days, with the young fledging about 30 days after hatching.


In the wild, virtually all parrot species require a hollow tree or a hollow log as a nest site. Because of this natural behavior, budgerigars most easily breed in captivity when provided with a reasonable-sized nest box. The eggs are typically one to two centimetres long and are pearl white without any colouration if fertile. Female budgerigars can lay eggs without a male partner, but these unfertilised eggs will not hatch. Females normally have a whitish tan cere, however when the female is laying eggs, her cere turns a crusty brown colour. Certain female budgies may always keep a whitish tan cere or always keep a crusty brown cere regardless of breeding condition. A female budgerigar will lay her eggs on alternate days. After the first one, there is usually a two-day gap until the next. She will usually lay between four and eight eggs, which she will incubate (usually starting after laying her second or third) for about 21 days each. Females only leave their nests for very quick defecations, stretches and quick meals once they have begun incubating and are by then almost exclusively fed by their mate (usually at the nest's entrance). Females will not allow a male to enter the nest, unless he forces his way inside. Depending on the clutch size and the beginning of incubation, the age difference between the first and last hatchling can be anywhere from 9 to 16 days. At times, the parents may begin eating their own eggs due to feeling insecure in the nest box.

Development

Eggs take about 18–20 days before they start hatching. The hatchlings are altricial – blind, naked, unable to lift their head, and totally helpless, and their mother feeds them and keeps them warm constantly. Around 10 days of age, the chicks' eyes will open, and they will start to develop feather down. The appearance of down occurs at the age for closed banding of the chicks. Budgerigar's closed band rings must be neither larger nor smaller than 4.0 to 4.2 mm.

They develop feathers around three weeks of age. (One can often easily note the colour mutation of the individual birds at this point.) At this stage of the chicks' development, the male usually has begun to enter the nest to help his female in caring and feeding the chicks. Some budgerigar females, however, totally forbid the male from entering the nest and thus take the full responsibility of rearing the chicks until they fledge.

Depending on the size of the clutch and most particularly in the case of single mothers, it may then be wise to transfer a portion of the hatchlings (or best of the fertile eggs) to another pair. The foster pair must already be in breeding mode and thus either at the laying or incubating stages, or already rearing hatchlings.

As the chicks develop and grow feathers, they are able to be left on their own for longer periods of time. By the fifth week, the chicks are strong enough that both parents will be comfortable in staying out of the nest more. The youngsters will stretch their wings to gain strength before they attempt to fly. They will also help defend the box from enemies, mostly with their loud screeching. Young budgerigars typically fledge (leave the nest) around their fifth week of age and are usually completely weaned between six and eight weeks old. However, the age for fledging, as well as weaning, can vary slightly depending on whether its age and the number of surviving chicks. Generally speaking, the oldest chick is the first to be weaned. Though it is logically the last one to be weaned, the youngest chick is often weaned at a younger age than its older sibling(s). This can be a result of mimicking the actions of older siblings. Lone surviving chicks are often weaned at the youngest possible age as a result of having their parents' full attention and care.

Hand-reared budgies may take slightly longer to wean than parent-raised chicks. Hand feeding is not routinely done with budgerigars, due to their small size, and because young parent raised birds can be readily tamed.