The house Sparrow, Passer domesticus (1758)
Phylum : Chordata
Class : Aves
Order : Passeriformes
Family : Passeridae
Genus : Passer
Species : P. domesticus
Subspecies : P.d. domesticus, P.d. balearoibericus, P.d. tingitanus, P.d. niloticus, P.d. persicus, P.d. biblicus, P.d. hyrcanus, P.d. bactrianus, P.d. parkini, P.d. indicus, P.d. hufufae, P.d. rufidorsalis
- Least concern
- 18 cm long and 40 g
The House Sparrow is a very social bird. It is gregarious at all seasons when feeding, often forming flocks with other types of bird. It roosts communally, and its nests are usually grouped together in clumps, and it engages in social activities such as dust and water bathing, and “social singing”, in which birds call together in bushes. The House Sparrow feeds mostly on the ground, but it flocks in trees and bushes. At feeding stations and nests, female House Sparrows are dominant despite their smaller size.
Most birds do not move more than a few kilometres. However, there is limited migration in all regions. Some young birds disperse long distances, especially on coasts, and mountain birds move to lower altitudes in winter. Two subspecies, bactrianus and parkini, are predominately migratory. Unlike the birds in sedentary populations that migrate, birds of migratory subspecies prepare for migration by putting on weight.
As an adult, the House Sparrow mostly feeds on the seeds of grains and weeds, but it is opportunistic and adaptable, and eats whatever foods are available. It can perform complex and unusual tasks to obtain food, such as opening automatic doors to enter supermarkets, clinging to hotel walls to watch vacationers on their balconies, and nectar robbing kowhai flowers. In common with many other birds, the House Sparrow requires grit to digest the hard seeds it eats. Grit can be either stone, often grains of masonry, or the shells of eggs or snails; oblong and rough grains are preferred.
Several studies of the House Sparrow in temperate agricultural areas have found the proportion of seeds in its diet to be about 90%. It will eat almost any seeds, but where it has a choice, it prefers oats and wheat. In urban areas, the House Sparrow feeds largely on food provided directly or indirectly by humans, such as bread, though it prefers raw seeds. The House Sparrow also eats some plant matter besides seeds, including buds, berries, and fruits such as grapes and cherries. In temperate areas, the House Sparrow has an unusual habit of tearing flowers, especially yellow ones, in the spring.
Animals form another important part of the House Sparrow’s diet, chiefly insects, of which beetles, caterpillars, dipteran flies, and aphids are especially important. Various non-insect arthropods are eaten, as are molluscs and crustaceans where available, earthworms, and even vertebrates such as lizards and frogs. Young House Sparrows are fed mostly on insects until about fifteen days after hatching. They are also given small quantities of seeds, spiders, and grit. In most places, grasshoppers and crickets are the most abundant foods of nestlings. True bugs, ants, sawflies, and beetles are also important, but House Sparrows will take advantage of whatever foods are abundant to feed their young. House Sparrows have been observed stealing prey from other birds, including American Robins.
House Sparrows can breed in the breeding season immediately following their hatching, and sometimes attempt to do so. Some birds breeding for the first time in tropical areas are only a few months old and still have juvenile plumage. Birds breeding for the first time are rarely successful in raising young, and reproductive success increases with age, as older birds breed earlier in the breeding season, and fledge more young. As the breeding season approaches, hormone releases trigger enormous increases in the size of the sexual organs and changes in day length lead males to start calling by nesting sites. The timing of mating and egg-laying varies geographically, and between specific locations and years. This is because a sufficient supply of insects is needed for egg formation and feeding nestlings.
Males take up nesting sites before the breeding season, by frequently calling beside them. Unmated males start nest construction and call particularly frequently to attract females. When a female approaches a male during this period, the male displays by moving up and down while drooping and shivering his wings, pushing up his head, raising and spreading his tail, and showing his bib.Males may try to mate with females while calling or displaying. In response, a female will adopt a threatening posture and attack a male before flying away, pursued by the male. The male displays in front of her, attracting other males, who also pursue and display to the female. This group display usually does not immediately result in copulations. Other males usually do not copulate with the female. Copulation is typically initiated by the female giving a soft dee-dee-dee call to the male. Birds of a pair copulate frequently until the female is laying eggs, and the male mounts the female repeatedly each time a pair mates.
The House Sparrow is monogamous, and typically mates for life. Birds from pairs often engage in extra-pair copulations, so about 15% of House Sparrow fledglings are unrelated to their mother’s mate. Male House Sparrows guard their mates carefully to avoid being cuckolded, and most extra-pair copulation occurs away from nest sites. Males may sometimes have multiple mates, and bigamy is mostly limited by aggression between females. Many birds do not find a nest and a mate, and instead may serve as helpers around the nest for mated pairs, a role which increases the chances of being chosen to replace a lost mate. Lost mates of both sexes can be replaced quickly during the breeding season. The formation of a pair and the bond between the two birds is tied to the holding of a nest site, though paired House Sparrows can recognise each other away from the nest.