House Sparrow

## Description

The House sparrow (Passer domesticus) is a small passerine bird found in most parts of the world. The extent of its range makes it the most widely distributed wild bird on the planet. Because of its numbers, ubiquity, and association with human settlements, the House sparrow is culturally prominent. It is extensively, and usually unsuccessfully, persecuted as an agricultural pest. It has also often been kept as a pet and was a food item. Though it is widespread and abundant, its numbers have declined in some areas.

## Appearance

The plumage of the House sparrow is mostly different shades of grey and brown. The sexes exhibit strong dimorphism: the female is mostly buffish above and below, while the male has boldly colored head markings, a reddish back, and grey underparts. The male has a dark grey crown from the top of its bill to its back, and chestnut brown flanking its crown on the sides of its head. It has black around its bill, on its throat, and on the spaces between its bill and eyes (lores). It has a small white stripe between the lores and crown and small white spots immediately behind the eyes (postoculars), with black patches below and above them. The underparts are pale grey or white, as are the cheeks, ear coverts, and stripes at the base of the head. The upper back and mantle are a warm brown, with broad black streaks, while the lower back, rump, and upper tail coverts are greyish brown. The male is duller in fresh nonbreeding plumage, with whitish tips on many feathers. Wear and preening expose many of the bright brown and black markings, including most of the black throat and chest patch, called the "bib" or "badge". The male's bill is dark grey, but black in the breeding season. The female has no black markings or grey crowns. Its upperparts and head are brown with darker streaks around the mantle and a distinct pale supercilium. Its underparts are pale grey-brown. The female's bill is brownish-grey and becomes darker in breeding plumage approaching the black of the male's bill. Juveniles are similar to adult female, but deeper brown below and paler above, with paler and less defined supercilia. Juvenile males tend to have darker throats and white postoculars like adult males, while juvenile females tend to have white throats. The bills of young birds are light yellow to straw, paler than the female's bill.

## Distribution

House sparrows are native to most of Europe, the Mediterranean Basin, a large part of Asia, and parts of North Africa. These birds are strongly associated with human habitation and can live in urban or rural settings. They are found in widely varied habitats and climates but typically avoid extensive woodlands, grasslands, and deserts away from human development. The only terrestrial habitats that House sparrows do not inhabit are dense forests and tundra.

## Behavior

House sparrows are very social birds. They are gregarious during all seasons when feeding, often forming flocks with other species of birds. They roost communally and while breeding nests are usually grouped together in clumps. House sparrows also engage in social activities such as dust or water bathing and "social singing", in which birds call together in bushes. These little birds feed mostly on the ground, but they flock in trees and bushes. At feeding stations and nests, females are dominant despite their smaller size, and they can fight over males in the breeding season. On the ground, House sparrows typically hop rather than walk; they can also swim when forced to do so by pursuit from predators. Most House sparrows do not move more than a few kilometers during their lifetimes. However, limited migration occurs in all regions. Some young birds disperse long distances, especially on coasts, and mountain birds move to lower elevations in winter. House sparrows are highly noisy. Most of their vocalizations are variations of their short chirping call that may sound like 'chirrup', 'tschilp', or 'philip'; this note is made as a contact call by flocking or resting birds, or by males to proclaim nest ownership and invite pairing. Much communal chirping occurs before and after the birds settle in the roost in the evening, as well as before the birds leave the roost in the morning. Aggressive males give a trilled version of their call, transcribed as 'chur-chur-r-r-it-it-it-it'. This call is also used by females in the breeding season, to establish dominance over males while displacing them to feed young or incubate eggs.

## Diet

House sparrows are omnivores and eat whatever foods are available. They feed mostly on the seeds of grains and weeds, buds, berries, and fruits such as grapes and cherries. They also commonly eat insects, mollusks, crustaceans where available, earthworms, and even vertebrates such as lizards and frogs.

## Reproduction

House sparrows are monogamous and typically mate for life. Many birds do not find a nest and a mate, and instead may serve as helpers around the nest for mated pairs; this role also increases the chances of being chosen to replace a lost mate. 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. House sparrows breed in colonies and generally produce 2 broods per year. Their nests are most frequently built in the eaves and other crevices of houses. Holes in cliffs and banks, or tree hollows, are also used. House sparrows sometimes excavate their own nests in sandy banks or rotten branches, but more frequently use the nests of other birds in banks and cliffs, and old tree cavity nests. The female lays 4 or 5 white, bluish-white, or greenish-white eggs, spotted with brown or grey. She develops a brood patch of bare skin and plays the main part in incubating the eggs which lasts for 11-14 days. The male helps, but can only cover the eggs rather than truly incubate them. The helpless chicks remain in the nest for 14 to 16 days and during this time, they are fed by both parents. The young can breed in the breeding season immediately following their hatching; however, in tropical areas, some birds start to breed when they are only a few months old and still have juvenile plumage.

## Population

### Population threats

The main threats to House sparrows include predation, in particular by Eurasian sparrowhawks, electromagnetic radiation from mobile phones, and diseases such as avian malaria. A primary cause of the decline seems to be an insufficient supply of insect food for nestling sparrows. Declines in insect populations result from an increase in monoculture crops, the heavy use of pesticides, the replacement of native plants in cities with introduced plants and parking areas, and possibly the introduction of unleaded petrol, which produces toxic compounds. House sparrows are also common victims of roadkill, especially in Europe.

### Population number

According to the IUCN Red List, the global House sparrow population size is 896,000,000-1,310,000,000 mature individuals. The European population consists of 134,000,000-196,000,000 pairs, which equates to 269,000,000-392,000,000 mature individuals. National population sizes include around 100-100,000 breeding pairs in China and around 100-100,000 breeding pairs in Russia. Overall, currently, this species is classified as Least Concern (LC) on the IUCN Red List but its numbers today are decreasing.

### Ecological niche

House sparrows consume large quantities of seeds and thus have an impact on various plant communities. They also serve as an important food source for birds of prey, domestic cats and dogs, and other predators that occur near human habitations.

## Fun Facts

House sparrows tolerate a variety of climates but prefer drier conditions, especially in moist tropical climates. They have several adaptations to dry areas, including a high salt tolerance and an ability to survive without water by ingesting berries.

House sparrows enjoy dust or water bathing and often do that in groups. Captive birds can even dive and swim short distances under the water.

House sparrows fly on average 45.5 km/h (28.3 mph) and make about 15 wingbeats per second.

In towns and cities, House sparrows often scavenge for food in garbage containers and congregate in the outdoors of restaurants to feed on leftover food and crumbs. They can perform complex 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 temperate areas, House sparrows have an unusual habit of tearing flowers, especially yellow ones, in the spring.