Eurasian sparrowhawk

Name and taxonomy

Carl Linnaeus described the bird in 1758 and placed it in the genus Falco. Mathurin Jacques Brisson moved it to Accipiter in 1760, where it has stayed. The genus holds small and medium woodland hawks, most of them called sparrowhawks or goshawks. Accipiter is simply the Latin for a hawk, and nisus is the Latin name of this bird. The English name goes back to Old English spearhafoc, the hawk that takes sparrows.

Six subspecies are usually accepted, and birds grow larger and paler towards the east. The nominate form breeds from western Europe to western Siberia and Iran. A separate race is resident on Madeira and the Canary Islands, and another on Sardinia and Corsica. It forms a superspecies with the rufous-chested sparrowhawk, a bird of eastern and southern Africa. English country names include blue hawk, hedge hawk, spar hawk and stone falcon.

Evolution and relatives

Accipiter is a large and old genus of forest hawks spread over most of the world. Its members share short wings and long tails, which is the standard build for hunting inside cover. Like other bird-eating hawks, the sparrowhawk shows a large size gap between the sexes. That gap is widest in the raptors that specialise on birds rather than mammals. The Madagascar sparrowhawk may belong to the same close group.

The northern goshawk is the nearest large relative in Europe and hunts the same woods. A female sparrowhawk and a male goshawk overlap in size and confuse many observers. The sparrowhawk is slimmer, shorter in the wing and faster in its wingbeats. The Levant sparrowhawk is a similar size, and the shikra and besra are smaller relatives in Asia. The grey-blue back of the adult male appears in other bird-hunting raptors, including the merlin.

Appearance

An adult male is 29 to 34 cm long with a wingspan of 59 to 64 cm. A female reaches 35 to 41 cm long with a wingspan of 67 to 80 cm. Males weigh 110 to 196 g and females 185 to 342 g. A female can be a quarter larger than her mate and roughly twice as heavy. In Britain, birds in the north are slightly bigger than birds in the south.

The male has a slate-grey back that sometimes looks blue, and rusty bars across the breast. From a distance those bars merge, and the underside looks plain orange. His eyes are orange-yellow or orange-red, and hers are bright yellow to orange. The female is brown above with brown bars below and a pale spot on the nape. A juvenile is warm brown with rusty edges above and coarse bars or spots below.

The wings are short and broad and the tail is long with a square end. Both features are tools for turning tightly between trunks and through gaps in a hedge. The legs are long and thin, and the middle toe is very long for grasping a bird in flight. A lump under that toe closes the gap in the grip, so nothing slips free. The bill is small, because it plucks and tears rather than kills. The dark back and pale front are countershading, which breaks up the outline against the sky.

Habitat and range

The sparrowhawk lives across the temperate and subtropical Old World. Its breeding range is huge, and the world population was put at 1.5 million birds in 2009. It breeds in woodland of almost any kind and prefers conifer or mixed stands. Cover next to open feeding ground is the pattern it looks for, often near a river. Unlike the goshawk, it settles happily in gardens, parks and city squares with tall trees.

Birds from northern Europe and Asia move south for the winter. Some reach north Africa, a few reach equatorial east Africa, and others reach India. Southern birds stay put or wander short distances. Ringing at Kaliningrad showed males moving an average of 1328 km and females 927 km. Juveniles set off before adults, and young females go before young males.

It is now one of the commonest raptors in Europe, beside the kestrel and the buzzard. In Ireland it is the commonest bird of prey, and it nests close to the middle of Dublin. English densities of 10 to 72 pairs for every 100 square kilometres have been measured. The island race granti holds about 100 pairs on Madeira and 200 pairs in the Canaries. iNaturalist carries more than 52554 observations of the species.

Diet and hunting

Small birds make up almost the whole diet, and one study put the share at up to 97 per cent. More than 120 bird species appear in the records, and single hawks often settle on a favourite. Males take tits, finches, sparrows and buntings, mostly under 40 g. Females take thrushes and starlings and can kill a bird of 500 g or more. Voles, shrews, bats, young rabbits and squirrels turn up now and then, and insects almost never.

The method is surprise, not speed over distance. The hawk waits under cover in a hedge, a copse or an orchard until a bird comes close. It then breaks out fast and low and closes the gap before the target reacts. A chase can end with the hawk turning upside down to take a bird from below. It will also follow prey into a bush on foot, or drop on it from a height. Only about one attack in ten succeeds.

Small victims die on impact or in the grip of the two long claws. A larger bird may live through the first seconds and die while the hawk plucks it. The hawk stands on the body, pulls the feathers out and eats the breast muscle first. Bones are usually left, and the bird coughs up a pellet of feather and fragments. A male eats about 40 to 50 g of food a day and a female about 50 to 70 g. Over a year one pair might take 2200 house sparrows, or 600 blackbirds, or 110 wood pigeons.

Behaviour and social life

The sparrowhawk is secretive and spends most of the year alone. It perches upright under cover and moves from perch to perch while it looks for a chance. The flight is a run of quick beats followed by a glide, which gives a wavy line across a field. Birds rise above the trees mainly to display, to look over a territory or to travel. Ian Newton listed seven hunting styles, from still-hunting to low quartering and hunting by sound.

A pair defends the ground around its nest but shares wider hunting range with neighbours. In a Norwegian forest, male home ranges averaged 9.2 square kilometres and female ranges 12.3. Ranges grow where prey is thin and shrink while a nest needs attention. A hunting bird may cover 2 to 3 km in a day. Most pairs hold a territory for one season, though some keep the same wood for eight years. A failed nest makes a bird more likely to move, and a new mate usually means new ground.

Communication and senses

Away from the nest the sparrowhawk is usually silent. Near the nest it gives a shrill cackle, faster when a rival or a person comes close. A softer note passes between the pair when the male arrives with food. The female has her own call for that moment, which carries well through the trees. Fledged young are noisy, and their begging can be heard from a long way off.

In spring the male performs a sky dance of deep dives, climbs and slow circles. He also dives at a perched or flying female to hold her attention. Eyesight carries the hunt, and the eye is packed with light-sensitive cells. Forward-facing eyes give the depth judgement a bird needs at speed among branches. Smell is weak, but taste seems sharp enough to reject food that would harm the bird. Great tits give one alarm call for a distant hawk that the hawk itself probably cannot hear well.

Reproduction and life cycle

Pairs breed once a year, from mid-April to the end of August. They choose a large wood that is neither too thick nor too open, so flight paths stay clear. The male does most of the building and sets the nest in a fork or on a low canopy branch. He uses loose twigs and builds a platform about 60 cm across, close to last year's nest. A lining of fine twigs or bark chips goes in when the eggs arrive.

The clutch is usually four or five pale blue eggs with brown spots. Each egg weighs about 22.5 g, and they are laid two or three days apart in the morning. The number of eggs depends on the female keeping her weight up while the male feeds her. Her weight peaks in May at laying and falls to its lowest in August. Chicks hatch after 33 days and are helpless and downy.

The female broods the chicks for the first 8 to 14 days while the male hunts for all of them. He brings up to six kills a day in the first week and about ten a day by the last week. The female starts hunting again once the young grow large. Young birds fly 24 to 28 days after hatching and stay near the nest for another month. Males mature faster than their bigger sisters and leave the nest sooner. Birds can breed at one year old, and most do so by three.

Predators and threats

Goshawks, tawny owls, eagle owls, peregrine falcons and golden eagles all kill sparrowhawks. Red foxes, stone martens and pine martens take birds and nests. A goshawk raiding a nest is met by the female, who often drives it off while the male calls. In one Scottish forest, 21 per cent of nestlings older than two days died in the nest. Starvation, wet weather, predators and desertion by the parents all played a part.

Blood parasites shape the hunt as well as the hawk. A bird carrying Leucocytozoon was 25 times more likely to be caught by a hawk. A bird carrying avian malaria was killed 16 times as often as a healthy one. Sparrowhawks in towns often collide with buildings and other structures while they hunt. Shooting continues in many parts of Europe, though at a level the population absorbs.

Population and conservation

The IUCN lists the Eurasian sparrowhawk as Least Concern, and the world total looks stable. Animal Diversity Web puts the figure above one million breeding pairs, plus many non-breeders. About 34 per cent of young birds survive their first year, and 69 per cent of adults survive each later year. The typical life is 4 years, and the record for a wild bird is 20.2 years. Female survival rises for three years and then falls away with age.

The European population collapsed after farmers began dressing seed with cyclodiene insecticides in 1956. Grain-eating birds carried the poison, and hawks that ate them stored it. Some hawks died outright, and others laid eggs with shells too thin to survive incubation. In west Germany the share of successful nests fell from about 80 per cent to 54 per cent. The species nearly vanished from East Anglia, where the chemicals were used most heavily.

Britain banned the seed dressings for autumn cereals in 1975, and the birds came back. Sweden saw the same fall and the same recovery once organochlorines went. British numbers rose by 108 per cent between 1970 and 2005. The RSPB reports a fall of about 25 per cent in the UK between 1995 and 2023. Body tissue from dead hawks is still tested for pollutants under a British monitoring scheme.

Relationship with humans

Gamekeepers and poultry keepers have fought the sparrowhawk for centuries. A parish in Berkshire paid a bounty on 106 sparrowhawk heads during the eighteenth century. One Norfolk estate killed 1645 hawks between 1938 and 1950. The species held on because so many non-breeding birds waited to fill an empty territory. Numbers rose sharply during both world wars, when keepers went to fight.

Racing pigeon keepers still blame the hawk for their losses. A Scottish study found that owners lose 56 per cent of racing pigeons each year. Sparrowhawks accounted for less than 1 per cent of those losses. In 2009 the Scottish Government moved a few hawks away from lofts at a cost of 25000 pounds. Only seven birds were caught, the data proved useless, and the trial was not repeated.

The hawk is also blamed for the decline of British songbirds. Long-term national bird census data does not support that charge. Songbird numbers rose and fell in the same pattern whether hawks were present or not. When pesticides removed the hawks, songbirds did not increase. Falconers have flown the species since at least the sixteenth century. Georgia has 500 registered sparrowhawkers, and the city of Poti has a monument to them.

In culture and myth

In Greek story, Nisus was a king of Megara whose daughter cut off his purple lock of hair. He was turned into a sparrowhawk, and the bird's scientific name still carries his name. Old Bohemian songs treat the sparrowhawk as a holy bird that lives in a grove of the gods. In those songs the birds perch on an oak above a murdered man and announce the crime. The South Slavic name comes from a root meaning doom, so people read omens from its flight.

In some parts of England people believed the cuckoo became a sparrowhawk for the winter. That idea probably grew from the barred breast the two birds share. A study with model birds showed that small birds treat a barred cuckoo as a hawk. Spearhafoc was an English personal name before the Norman Conquest of 1066. John Aubrey recorded a hawk that died tangled on a crown of the White Tower in 1695.

The falconer's word for the male is musket, from a Latin word for a fly. A crossbow bolt and then a gun took the same name, because both were small for their kind. Shakespeare has Mistress Ford greet a page as her eyas musket in The Merry Wives of Windsor. Tennyson wrote of a sparrowhawk that held a nightingale in a wicked jail. Ted Hughes wrote a poem about the bird, and Hermann Hesse used it in Demian.