Man's best friend?

No wild bird species has stuck so loyally to Homo sapiens as the house sparrow. BILL NAYLOR examines the nature of the link and the causes of the recent rupture, as sparrows have declined

- BILL NAYLOR

ALTHOUGH no longer a contender for the most numerous species, the house sparrow (Passer domesticus) is still the most well known and widely distributed bird, occupying two thirds of the globe, mainly in areas it has colonised itself.

A variety of unrelated birds are known as sparrows but true sparrows (Passeridae), apart from being sombre plumaged, share many similarities with weavers. The house sparrow builds a domed nest with a side entrance, has a horny palate and undergoes a complete juvenile moult at two or three months, which in finches is only partial.

In personality they’re extrovert and vocal, just like weavers. Originating in Asia, the house sparrow spread westwards into Europe as part of the population evolved into the Spanish sparrow (P. hispaniolensis) with which it now hybridises. The Italian sparrow may be a hybrid of the two or a full species (P. italiae), while the tree sparrow is a distant relative of all three.

As agriculture and urbanisation increased, so did the house sparrow. During the 1800s it was introduced into a number of countries as an insect pest controller, or a reminder to European colonists of their homeland. Many people of my generation were introduced to bird behaviour by the activities of their local colony of house sparrows.

The word “sparrow” comes from the Anglo Saxon spearwa and was given to a homely or chirpy person. The bird’s vocabulary is finch-like, the most familiar call being chirrup.