thumb|Northern sparrowhawk call

The Eurasian sparrowhawk (Accipiter nisus), also known as the northern sparrowhawk or simply the sparrowhawk, is a small bird of prey in the family Accipitridae. Adult male Eurasian sparrowhawks have bluish grey upperparts and orange-barred underparts; females and juveniles are brown above with brown barring below. The female is up to 25% larger than the male – one of the greatest size differences between the sexes in any bird species. Though it is a predator which specialises in catching woodland birds, the Eurasian sparrowhawk can be found in any habitat and often hunts garden birds in towns and cities. Males tend to take smaller birds, including tits, finches and sparrows; females catch primarily thrushes and starlings but are capable of killing birds weighing or more.

The Eurasian sparrowhawk is found throughout the temperate and subtropical parts of the Old World; whilst birds from the northern parts of the range migrate south for winter, their southern counterparts remain resident or make dispersive movements. Eurasian sparrowhawks breed in suitable woodland of any type, with the nest, measuring up to across, built using twigs in a tree. Four or five pale blue, brown-spotted eggs are laid; the success of the breeding attempt is dependent on the female maintaining a high weight while the male brings her food. The chicks hatch after 33 days and fledge after 24 to 28 days.

The probability of a juvenile surviving its first year is 34%, with 69% of adults surviving from one year to the next. Mortality in young males is greater than that of young females and the typical lifespan is four years. This species is now one of the most common birds of prey in Europe, although the population crashed after the Second World War. Organochlorine insecticides used to treat seeds before sowing built up in the bird population, and the concentrations in Eurasian sparrowhawks were enough to kill some outright and incapacitate others; affected birds laid eggs with fragile shells, which broke during incubation. However, its population recovered after the chemicals were banned, and it is now relatively common, classified as being of least concern by BirdLife International.

The Eurasian sparrowhawk's hunting behaviour has brought it into conflict with humans for hundreds of years, particularly racing pigeon owners and people rearing poultry and gamebirds. It has also been blamed for decreases in passerine populations. Studies of racing-pigeon deaths found that Eurasian sparrowhawks were responsible for less than 1%. Falconers have utilised the Eurasian sparrowhawk since at least the 16th century; although the species has a reputation for being difficult to train, it is also praised for its courage. The species features in Teutonic mythology and is mentioned in works by writers including William Shakespeare, Alfred, Lord Tennyson and Ted Hughes.

Taxonomy

Within the family Accipitridae, the Eurasian sparrowhawk is a member of the large genus Accipiter, which consists of small to medium-sized woodland hawks. Most of the Old World members of the genus are called sparrowhawks or goshawks.

This species is prevalent in most woodland types in its range, and also in more open country with scattered trees. though only 10% of its hunting attacks are successful. these include its blunted wings, which allow it to fly through narrow gaps in hedges and fences, and its long, square-edged tail, which the bird uses to aid itself in carrying out tight turns, such as those required to negotiate close stands of trees.

Male Eurasian sparrowhawks regularly kill birds weighing up to and sometimes up to or more; females can tackle prey up to or more. A recent study found that on average, female sparrowhawk prey were two and a half times heavier than that of the male. The weight of food consumed by adult birds daily is estimated to be for males and for females. During one year, a pair of Eurasian sparrowhawks could take 2,200 house sparrows, 600 common blackbirds or 110 wood pigeons. are sometimes caught but insects are eaten only very rarely.

Another study found that the risk of predation for a bird targeted by a Eurasian sparrowhawk or Eurasian Goshawk increased 25-fold if the prey was infected with the blood parasite Leucocytozoon, and birds with avian malaria were 16 times more likely to be killed.

Falconry

alt=Three men with Eurasian sparrowhawks perching on their fists|thumb|right|The Eurasian sparrowhawk is popular with [[Falconry|falconers in Georgia.]]

The Eurasian sparrowhawk has been used in falconry for centuries and was favoured by Emperor Akbar the Great (1542–1605) of the Mughal Empire. There is a tradition of using migrant Eurasian sparrowhawks to catch common quail in Tunisia and Georgia, where there are 500 registered bazieri (sparrowhawkers) and a monument to bazieri in the city of Poti. Eurasian sparrowhawks are also popular in Ireland. It also features in Teutonic mythology. In some areas of England, it was believed that the common cuckoo turned into a Eurasian sparrowhawk in winter.

References

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Further reading

  • Ageing and sexing (PDF; 5.8&nbsp;MB) by Javier Blasco-Zumeta & Gerd-Michael Heinze
  • RSPB webpage with sound and video files. Retrieved 10 July 2009
  • Global Raptor Information Network species account . Retrieved 4 March 2010