Birds
House Sparrow
Passer domesticus · also called English sparrow, sparrow
The house sparrow is the most familiar small bird in the world and one of the easiest to overlook. It lives where we live, eats what we spill, and nests in our walls — and in much of Europe it has been quietly slipping away.
Overview
Passer domesticus is native to Europe, the Middle East, North Africa, and Asia and has been introduced almost everywhere else. It is a stocky brown bird, the male marked with a grey crown, chestnut nape, and black bib, the female plain. It eats mostly seeds and grain, but feeds its chicks on insects.
The human bird
The house sparrow is a commensal of people, rarely found away from farms and buildings. It followed the spread of farming out of the Middle East, then colonial shipping around the globe. Released in Brooklyn around 1851, it crossed North America within 50 years.
The badge
A male’s black bib signals status: bigger-bibbed males are older, fitter, and dominant, and rivals defer to the badge without fighting.
The decline
Since the 1980s, house sparrows have fallen by more than half across much of Europe, with London down 60–70%. The causes — fewer nest sites, fewer insects for chicks, pollution, predation — are debated and probably act together.
Status
Globally Least Concern, with a population over a billion, but decreasing, and a bird of real conservation concern in its native range.
House Sparrow: common questions
Why are house sparrows disappearing from cities?
No single cause has been pinned down and it is probably a combination. Modern buildings have fewer of the nooks, eaves, and holes sparrows nest in, and tidy paved gardens produce fewer weed seeds and far fewer insects, which chicks need in their first week. Air pollution has been linked to poorer chick survival, as has a shortage of aphids and other small invertebrates. Predation by cats and by sparrowhawks that have moved into towns plays a part, and disease, including a form of avian malaria, has been suggested. The declines are real and well documented across northwestern Europe, but the picture varies from city to city.
How did house sparrows get to North America?
They were deliberately introduced. The best-known release was in Brooklyn, New York, around 1851 and 1852, when birds were brought from England, partly out of homesickness among European immigrants and partly in the mistaken hope they would control caterpillars. Further introductions followed in other cities. The sparrows thrived on grain spilled by horses and on the waste of a growing urban population, and within about 50 years they had spread across the continent to the Pacific and into Mexico and Canada, one of the fastest colonisations by any introduced bird.
What does the black bib on a male sparrow mean?
It is a status signal. Male house sparrows have a black patch on the throat and upper breast that varies in size between individuals, and research has shown that males with larger patches tend to be older, in better condition, and dominant over smaller-badged males at feeding sites. Rivals appear to read the badge directly; experiments that enlarged a male's patch with dye raised his standing in the group. The system lets sparrows sort out a pecking order without constant fighting, since a glance at the bib settles most disputes.
Are house sparrows a pest?
In places where they were introduced they can be. Large flocks eat grain and sprouting crops, foul buildings, and take over the nest holes of native cavity nesters such as bluebirds and tree swallows, sometimes killing the adults or young inside. For that reason the species has no legal protection in the United States. In its native range the view is very different; there the house sparrow is a declining bird of conservation concern, and its long association with human settlements has made its disappearance from streets and gardens a noticed and lamented change.