The House Sparrow (Passer domesticus) is a very social bird. It is gregarious at all seasons when feeding, often forming flocks with other types of bird. It also roosts communally, 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. Non-breeding sparrows roost in large groups in trees, gathering beforehand and calling together. At feeding stations and nests, female House Sparrows are dominant despite their smaller size (Johnston 1969).
In house sparrow populations, the risk of predation is seemingly higher in fields where birds scan more frequently, compared to enclosed habitats such as cattle sheds, where scanning is negatively influenced by flock size but positively influenced by distance from cover. Individual time budgets are more influenced by flock size than by seed density in the fields but more influenced by seed density than by flock size in enclosed habitats. Higher rates of scanning results in greater flock vigilance and longer flight distances in the fields but flight distance is negatively influenced by the density of seeds on which birds are feeding (Barnard 1980).
Males with large plumage badges on their breast are more dominant in winter flocks, irrespective of age, body size and body condition index. The frequencies of male attacks are higher with increasing similarity of badges of the two contestants. Male house sparrows are more frequently engaged in attacks with males having a similar badge size when they have large badges, rather than when they have small ones. Badge size does not change consistently with the age of the male house sparrow. Breeding territory owners approach closer to, and move less frequently in response to, a house sparrow model with a small badge than to one with a large badge. This experiment is consistent with a status signalling function of badge size variation in house sparrow populations (Moller 1987).
Reference List:
- Barnard.J.C., (1980) Flock feeding and time budgets in the house sparrow (Passer domesticus). Animal Behaviour, 28, 295-309.
- Johnston.F.R., (1969). “Aggressive Foraging Behaviour in House Sparrows”. The Auk, 86, 558–559.
- Moller.P.A., (1987) Variation in badge size in male house sparrows (Passer domesticus): evidence for status signalling. Animal Behaviour, 35, 1637-1644.
