Sparrowhawk

The Sparrowhawk is the bird-hunting hawk of British woods, towns and gardens: a small hawk with blunt-tipped wings, a long tail, long thin yellow legs and yellow to orange eyes. Both sexes are barred underneath, but males and females differ in colour and, very obviously, in size.¹

In flight it makes a T shape, a long square-ended tail behind blunt-tipped wings, and it moves with a few quick wingbeats and a short glide. It hunts close to cover, using trees, hedges and buildings to hide its approach.

Adult males are blue-grey above, with rufous cheeks and orangey-brown bars on a whitish breast, and yellow-orange to orange-red eyes. Females are grey-brown above and barred dark brown below, with a fairly obvious pale stripe over the eye and bright yellow to orange eyes. Young birds in their first year look like browner females, with rusty edges to the back feathers, broader bars below and pale yellow eyes.²

In the breeding season a female is about double a male's weight.³ More on telling them apart: male, female and young Sparrowhawks.

Sparrowhawks are 28-38 cm long (11-15 in), with a wingspan of 55-70 cm (22-28 in). Males weigh 110-196 g and females 185-342 g. Weighed by ringers, live British males average 151 g and females 266 g, so a female is on average about 1.75 times as heavy, with a wing about 18% longer.⁴

The wingspans by sex are handbook figures; the averages are from live British birds caught by ringers. For comparison, a Kestrel is 32-35 cm long with a 71-80 cm wingspan, and a Goshawk 48-62 cm.^{5, 6}

Four birds cause most confusion. For the commonest, see Kestrel or Sparrowhawk?

• Kestrel: more pointed wings, often hovers, and pale below with black speckles rather than bars; a dark "tear" mark below each eye.
• Goshawk: like a much bigger, stockier Sparrowhawk. A female is about the size of a Buzzard, with thicker legs, a bold white eyebrow, a dark patch behind the eye and more rounded tail corners. Some female Sparrowhawks are big enough to cause confusion. See Goshawk or Sparrowhawk?
• Cuckoo: barred underparts like a Sparrowhawk's and a long tail, but a blue-grey head and chest, pointed wings, and here only in spring and summer.
• Merlin: a small, compact falcon with pointed wings, a narrow, square-ended tail and dark eyes; the male's rusty underparts are streaked, not barred.

The Cuckoo's likeness may be more than chance: in experiments, Reed Warblers were more reluctant to approach and mob cuckoo models with barred underparts than models without bars, and the researchers suggest the bars make a cuckoo look like a hawk.⁷ A study with more aggressive hosts in China found no such effect, so the idea is still debated.⁸

Mostly silent away from the nest. The main call is a cackling kek-kek-kek, which varies in loudness and speed; young birds begging for food give thin, drawn-out "peeay" notes.² The recording in the player is a young bird calling in Normandy in August. Hear more, and see when they call, on our Sparrowhawk call page.

Sparrowhawks live all year across almost all of Britain and Ireland, breeding in 83% of the UK's 10-km squares. They are missing only from the northern Scottish uplands and some island groups, and are commonest in lowland areas such as eastern England.⁴

They are birds of woods, conifer, broadleaved or mixed, and especially of woods mixed with open ground, and they hunt along hedges, over farmland and in parks and gardens. Once apparently absent from towns, they now live in many towns and cities. Comparing one urban and one rural population in Scotland in 2009-12, urban territories were occupied in more years (66.8% against 42.8%) and more urban nests succeeded (97.2% against 80.5%).⁹

Listen for the sudden alarm calls of small birds and watch for them scattering from a feeder: often the only sign a Sparrowhawk is passing. Look for the T-shaped silhouette and flap-and-glide flight over woods and gardens.

Not in Britain and Ireland, where they stay all year. Birds from further north and east do move: 78 birds ringed abroad have been found in Britain and Ireland, 30 of them ringed in Norway, 18 in Germany and 15 in the Netherlands, and one young male crossed from North Ronaldsay in Orkney to Helgoland in Germany, 853 km, in seven days.¹⁰ In the far north of Europe and across most of Asia, Sparrowhawks migrate; a few reach sub-Saharan Africa, and Siberian birds winter in southern and South-east Asia.

Almost entirely birds, mostly small ones: finches (especially Chaffinches), sparrows, tits, buntings, pipits and larks, with thrushes and Starlings often taken. Prey rarely weighs more than about 120 g, though a female can take a pigeon. In spring and summer they catch many young birds just out of the nest, and their own breeding is timed so that their chicks are in the nest when fledglings are most plentiful.²

The smaller males hunt more in dense woodland and take smaller prey on average; females hunt more in the open and take larger birds. Mammals, lizards and insects are rare extras. More on what Sparrowhawks eat and how they hunt.

Pairs nest in woods, preferably conifer or mixed, building a new platform of sticks each year, often near their old nests, on a branch or in a fork 2-35 m up.²

In the UK the first eggs are laid on average on 11 May. A clutch is usually four or five eggs, incubated by the female for about 33 days, and the young leave the nest at 26.5-30.5 days old;⁴ males leave about four days before females.¹¹ In Newton's long study, the male did nearly all the hunting for the family until the chicks were about half grown; then the female hunted too. They raise one brood a year. More on Sparrowhawk nests, eggs and chicks.

A Sparrowhawk hunts by surprise. It flies fast between trees and bushes, using cover to hide its approach, or waits on a hidden perch, then dashes at a bird that has not seen it. In a study on a Scottish estuary in winter, most hunts lasted under a minute, with a single attack from a perch at birds on the ground, usually within 100 m, and about one attack in ten on Redshanks and Dunlins succeeded.¹²

For most of the year it eats one to three large meals a day, separated by long fasts.¹³ Pairs hold nesting places, spaced 0.6 km to several kilometres apart in continuous woodland, closer together where small birds are plentiful.³

The typical life expectancy of a Sparrowhawk that reaches breeding age is four years, and most start breeding at a year old.⁴ Many never get that far: in a long study in southern Scotland, fewer than half of young females survived their first year, though more than 65% of females aged three to five survived each year.³

The oldest on the BTO's longevity list is a female ringed as a nestling at Micheldever, Hampshire, in 1982 and found dead, hit by a car, at Pennington near Lymington in 1999: 17 years, 1 month and 11 days.¹⁴ The oldest on EURING's European list is a Dutch bird of 21 years 7 months, found dead after hitting a window. EURING counts a bird's age from its likely hatching year, a minimum for one ringed full-grown.¹⁵

Goshawks kill Sparrowhawks; Tawny Owls occasionally take chicks, and Red Squirrels and Jays take eggs. Of 341 Sparrowhawks found dead and sent to scientists in 1963-79, 34% had hit a window, wires or another obstacle, 7% were road or rail casualties, at least 11% had been shot and 9% had starved; such samples lean towards deaths near people.¹⁶

Amber-listed in the UK and of Least Concern worldwide. About 31,000 pairs breed in the UK (2016 estimate).⁴

In the late 1950s and early 1960s, organochlorine pesticides crashed the population, probably mainly through aldrin and dieldrin, used to dress seed grain, which poisoned adults; DDE from DDT also thinned eggshells so that eggs broke. In the most arable parts of eastern England the hawks all but vanished: in south Lincolnshire, Huntingdonshire and most of Cambridgeshire no nest was found for more than 20 years.¹⁷

Restrictions on the chemicals from the early 1960s, voluntary agreements rather than legal bans, let them return, probably mainly because more adults survived; they spread east from the north and west. In Rockingham Forest, Northamptonshire, Sparrowhawks nested again in 1979 after about 20 years: three nests that year, 84 in 1989.¹⁸

Numbers rose steeply until the mid-1990s. Since then the BTO describes them as broadly stable, with a moderate fall in England over the past ten years;⁴ the RSPB gives a 25% decline between 1995 and 2023.¹

Sparrowhawks, their nests and eggs are protected by law. In England and Wales it is an offence to intentionally kill, injure or take a wild bird, to take, damage or destroy its nest while it is in use or being built, or to take or destroy its eggs; in Scotland the same applies, intentionally or recklessly,¹⁹ and so it does in Northern Ireland.²⁰ Illegal killing still happens: RSPB investigators confirmed 63 Sparrowhawks as victims of persecution in the UK between 2009 and 2023, 39 of them shot or shot at, 13 trapped and 6 poisoned.²¹