ANIMAL ESTATE client 8.06: HOUSE SPARROW
FOR ANIMAL ESTATES 8.0: LONDON
SCIENTIFIC NAME: Passer domesticus
RANGE: The House Sparrow is one of about 25 species in the genus Passer, and occurs naturally in most of Europe, the Mediterranean region, and much of Asia. Its intentional or accidental introductions to many regions, including parts of Australia, Africa, and the Americas, make it the most widely distributed wild bird. The House Sparrow originated in the Middle East and spread, along with agriculture, to most of Eurasia and parts of North Africa. Since the mid-nineteenth century, it has reached most of the world, due chiefly to deliberate introductions, but also through natural dispersal and ship-borne travel.
HABITAT: The House Sparrow is strongly associated with human habitations, and can live in urban or rural settings. Though found in widely varied habitats and climates, it typically avoids extensive woodlands, grasslands, and deserts away from human development. It reaches its greatest densities in urban centres, but its reproductive success is greater in suburbs, where insects are more abundant. It tolerates a variety of climates, but prefers drier conditions due to adaptations which allow a high salt tolerance and an ability to survive without water by ingesting berries.
HOME CONSTRUCTION: It roosts communally, and its nests are usually grouped together in clumps, while non-breeding House Sparrows roost in large groups in trees. Nests are most frequently built in the eaves and other crevices of houses as well as holes in cliffs and banks, or in tree cavities. It sometimes excavates its own nests in sandy banks or rotten branches, but it more frequently uses the nests of other birds: those of swallows in banks and cliffs, and old tree cavity nests. It usually uses unused nests, though it sometimes usurps actively used nests.
The House Sparrow nests more commonly in tree holes in North America than in Europe. Especially in warmer areas, the House Sparrow may build its nests in the open, on the branches of trees, especially evergreens and hawthorns; or in the nests of large birds such as storks or magpies. Less common nesting sites used by the House Sparrow include streetlights and neon signs, favoured for their warmth, and the old open-topped nests of other songbirds, which are domed over. Nest building occurs throughout the year, but especially after moult in autumn.
BUILDING MATERIALS: The nest is usually domed, though it sometimes is not roofed over in enclosed sites. It has an outer layer of stems and roots, a middle layer of dead grass and leaves, and a lining of feathers, as well as paper and other soft materials. Nest typically have external dimensions of 20 × 30 cm (8 × 12 in), but their size varies greatly. The building of the nest is initiated by the unmated male who begins construction while displaying to females. The female assists in building, but is less active than the male.
BUILDING MOTIVATION: Most nest sites, depending on climate, require the similar basic criteria: Shelter, warmth and security. In colder areas House Sparrows build specially created roost nests, or roost in streetlights, to avoid losing heat during the winter.
MAKING A HOUSE SPARROW HOUSE: Conservation organisations have encouraged the use of special nest boxes for sparrows. These only differ from a standard bird box in a few ways and should be easy to construct with basic materials and tools. The particular requirements are as follows:
THREATS: Sparrows are very resilient and for their size have remarkably few serious predators. The predators include: Domestic cats, hawks, owls, and other predatory birds, corvids, smaller squirrels, and even humans (the House Sparrow has been consumed by humans in many parts of the world, and still is in parts of the Mediterranean). Most species of bird of prey have been recorded preying on the House Sparrow in places where there are extensive records. Accipiters and the Merlin in particular are major predators, though cats likely make a greater impact on House Sparrow populations. The House Sparrow is host to a huge number of parasites and diseases, and the effect of most is unknown. The commonly recorded bacterial pathogens of the House Sparrow are often those common in humans, and include Salmonella and Escherichia coli. Salmonella epidemics in the spring and winter can kill large numbers of sparrows.
People have a love-hate relationship with the house sparrow. The House Sparrow has an extremely large range and population, and is not seriously threatened by human activities, so it is assessed as Least Concern for conservation on the IUCN Red List of Threatened Species. In Great Britain, populations peaked in the early 1970s but have since declined by 68 percent overall, and about 90 percent in some regions. Various man-made causes for the dramatic decreases in population have been proposed. They include electromagnetic radiation from mobile phones, and a shortage of nesting sites due to loss of habitat and food; the decline in the insect population is caused by an increase of monoculture crops, the heavy use of pesticides, the replacement of native plants in cities with introduced plants and possibly the introduction of unleaded petrol, which produces toxic compounds such as methyl nitrite.
Protecting insect habitats on farms, and planting native plants in cities benefit the House Sparrow, as does establishing urban green spaces. House sparrows are protected under the Wildlife and Countryside Act 1981, which makes it illegal to intentionally kill, injure or take a house sparrow, or to take, damage or destroy an active nest or its contents.
INTERESTING FACTS:
- The House Sparrow was among the first animals to be given a scientific name in the modern system of biological classification.
- The only habitats in which the House Sparrow does not occur are dense forest and tundra.
- It has been recorded breeding in a coalmine 640 metres (2,100 ft) below ground.
- It can perform complex and unusual tasks to obtain food, such as opening automatic doors to enter supermarkets!
- In temperate areas, the House Sparrow has an unusual habit of tearing flowers, especially yellow ones, in the spring.
- The House Sparrow is also a common victim of road kill; on European roads, it is the bird most frequently found dead.
- Only about 20 to 25 percent of birds hatched survive to their first breeding season.
- The oldest known wild House Sparrow lived for nearly two decades; it was found dead 19 years and 9 months after it was ringed in Denmark. The oldest recorded captive House Sparrow lived for 23 years.
- A house sparrow’s retina has 400,000 photoreceptors per square millimetre.
- The size of a house sparrow’s bib indicates its place in the pecking order.
RESOURCES:
Wikipedia
Royal Society for the Protection of Birds
Birds of Britain
Garden Birds
Beautiful Britain
House Sparrow
BBC
Bird Facts
Bird Guides
Kate Vincent
(All accessed 05.10.11)
COMPILED BY: Mark Martines and Dan (Eva) Xie