Jackdaw

A Jackdaw is a small crow, smaller than a Carrion Crow or a Rook, and often seen perched on chimneys and rooftops. Look for the pale grey hood over the back of the head and neck, which sets off a black cap and face, and for the eye: silvery white, it stands out from the dark plumage. The bill is short and stubby, the body dark grey with a faint bluish sheen above, and the legs are black.

Seen well, the tail is fairly long and slightly rounded at the tip, and a Jackdaw can raise its crown feathers into a slight crest. Birds in Britain and Ireland are darker than those in Scandinavia, especially on the nape, with a blacker face and throat and little or no pale collar. Scandinavian birds, with a paler nape and a clear whitish collar at its base, occasionally winter in England.

Jackdaws are 34-39 cm (13-15 in) long, with a wingspan of 67-74 cm (26-29 in). Live adults weighed by ringers average about 232 g (8 oz), and most weigh 196-265 g (7-9 oz); males are a little heavier, averaging 241.8 g against 225.5 g for females.¹

Males and females look alike. Young birds out of the nest in early summer are browner and softer-looking, without the adult's gloss, and their eyes are darker: bluish rather than silvery. Some keep a dark eye until the end of their first winter. By their first autumn most head and body feathers have been replaced, and a young Jackdaw looks like an adult apart from its older, worn wing and tail feathers.

Carrion Crow. Much bigger and glossy black all over, with a large, heavy black bill and no grey hood.

Rook. Much bigger, with a long, pointed bill. Adults have bare greyish-white skin at the base of the bill, and Rooks look shaggy round the legs. Rooks and Jackdaws often feed and roost together in winter.

Raven. Far bigger, with a thick bill, a shaggy throat and a wedge-shaped tail.

Chough. A long, curved red bill and red legs. At a distance, a tumbling flock of Choughs can look like Jackdaws.

The Jackdaw's name comes from its call, a short, hard "chack" or "jack". Birds give it singly, or repeat it quickly seven or eight times as they meet and gather. A softer "tyaw" sometimes follows, and Jackdaws also have a crow-like "caw". Chicks beg loudly in the nest at feeding time.

In late summer, newly fledged young give a drawn-out "cheeaow", like a Chough's call, which can catch you out, though sooner or later they give a "chack" too. The recording on this page, from the Netherlands, is a flock calling: a run of short, sharp notes, each falling in pitch.

Jackdaws live in Britain and Ireland all year. They are birds of open country with scattered trees: mixed farmland, parks, gardens and churchyards, quarries and sea cliffs. They avoid treeless country and large forests, and favour villages, smaller towns and older suburbs with chimneys over big city centres.

In the 2007-11 atlas they were found in 2,504 of the UK's 10-km squares in the breeding season (83%) and 2,558 in winter (85%), absent only from much of north-west Scotland and some of north-west Ireland.¹ They have spread north through the Scottish islands and now breed as far north as Shetland.

Beyond Britain and Ireland they range across Europe and north-west Africa, and east through Turkey and Kashmir to western China, western Mongolia and south-central Siberia.

Most Jackdaws in Britain and Ireland stay all year. In Britain some leave higher ground in winter and move south-west, many as far as Ireland, and birds from northern Europe join them for the winter.

Ringing shows the links. The BTO's recovery summary lists 24 reports of Jackdaws ringed abroad and found in Britain and Ireland, half of them from the Netherlands, and 8 of birds ringed here and found abroad.² The longest move within Britain and Ireland is 779 km: two birds ringed as nestlings at Orfordness, Suffolk, in 2007 and 2012 were both found dead at a landfill site in Caithness on 9 November 2015.²

Jackdaws are omnivores. In one study, 84% of the diet was plant material such as grain, seeds and berries, but in the breeding season the birds ate mainly animal food.³ In summer they take grasshoppers, ants, flies, beetles and caterpillars, especially those of the green oak tortrix moth.

Most food is found on the ground. A Jackdaw walks with a confident, strutting gait and side-hops to grab prey, and in gardens it often works over lawns for invertebrates. It also rides on sheep and cattle to pick off their parasites, snaps up flying ants in the air, searches the tideline for sandhoppers and chases other birds to make them drop their food. It takes household scraps, and can become cautiously tame at picnic sites and in parks. Jackdaws rarely store food.

A few individuals specialise in taking other birds' eggs. On Skokholm, in Wales, Jackdaws caused as much as 60% of the egg losses of the island's Guillemots, though cases like this seem to be unusual.³

Jackdaws visit gardens for food and for nest material, and come to feeders, though they seldom stay long. If you feed birds, the RSPB's current guidance is to pause seed and peanuts from 1 May to 31 October, when disease spreads more easily, and to use hanging feeders rather than bird tables, cleaned every week.⁴

Jackdaws nest in holes: in trees, chimneys, churches and other buildings, in crevices in quarries and sea cliffs, and even in rabbit burrows, mine shafts and bridges. They also take to large nest boxes, and rarely take over an old Rook or Magpie nest. Several pairs often nest close together in a loose colony.

Both birds build. The base is a mass of sticks and twigs with mud and dung, holding a deep, thick cup of moss, rotten wood, feathers, fur and wool. Each new nest goes on top of the old ones, so some nests grow very large.

Sources differ on when laying starts. BTO nest records give an average first-egg date of 30 March, ranging from 12 March to 18 April;¹ Birds of the World gives laying from late April in Britain.³

A clutch is usually 4-5 eggs (2-9 recorded), which the female incubates alone for about 20 days; both parents feed the chicks, which leave the nest at about 32 days.¹ Pairs raise one brood a year.

When food runs short, the youngest chicks in a brood die quickly, and losing half a brood is common.^{1, 5} A review of studies across Europe found that Jackdaws nesting further from countryside feeding grounds laid smaller clutches and raised fewer young, and in experiments with town-nesting pairs, extra high-quality food given until the chicks fledged improved their survival.⁶

After fledging, families soon join others in big summer flocks. Young Jackdaws first breed at about two years old.

Chimneys suit Jackdaws, which nest in towns for the warmth and the cavities that chimneys give them. Like all wild birds, Jackdaws, their eggs and their nests while in use or being built are protected by law: by the Wildlife and Countryside Act 1981 in Great Britain and the Wildlife (Northern Ireland) Order 1985, which in Scotland and Northern Ireland also cover reckless acts.^{7, 8}

Jackdaws are sociable birds. Pairs stay together for years and are rarely apart: even in a big flock, the pairs can often be picked out. A DNA study of a nest-box colony found no chicks fathered outside the pair and no eggs laid in another pair's nest.⁵

Jackdaws are more at ease with people than Crows or Rooks are, but still cautious.

In winter, Jackdaws gather at night in big communal roosts, often with Rooks, flying noisily over the roost as they arrive and leave. A roost of hundreds or even thousands of birds often leaves together in a sudden mass departure in the morning, and field recordings and a large-scale experiment showed that the birds use their calls to coordinate when to go.⁹

In the air Jackdaws are quicker than the bigger crows. Flocks tumble and soar, and hang in the air over cliff faces.

In an experiment with pictures fixed to nest boxes, a Jackdaw face with bright eyes kept prospecting Jackdaws away best, which suggests the pale eyes may help warn rivals off an occupied nest hole.¹⁰

Jackdaws can learn about people from each other: in an experiment, wild breeding Jackdaws that heard recorded Jackdaw alarm calls while a stranger stood near their nest were warier of that person afterwards.¹¹ In tests with Jackdaws raised in close contact with people, the birds were slower to take food when a person's eyes were on it, and could use a familiar person's deliberate signals to find hidden food.¹²

A scolding call brings other Jackdaws to mob a threat: in playback tests at nest boxes, the calls of the box's own owners drew the most birds, ahead of other colony members, strangers and Rooks.¹³

A Jackdaw that survives to breed typically lives about five years: about 69% of adults survive from one year to the next, but only about 40% of young birds live to the age of two.¹

The oldest Jackdaw on the British and Irish longevity list was ringed as a nestling at Slimbridge, Gloucestershire, in May 2001, and its ring was read on the living bird there in November 2020: 19 years 5 months 8 days later.¹⁴ The oldest on the European list is a German bird of 24 years 3 months, reported as taken by a cat; for birds ringed as adults EURING counts a minimum age from the likely hatching year, while the BTO gives the time since ringing.^{14, 15}

Jackdaws are doing well. They are Green-listed in the UK, and Least Concern worldwide with a stable trend.^{1, 16} About 1.55 million pairs breed in the UK (a 2016 estimate).¹⁷

The UK breeding population has risen 139% since 1967.¹ The Breeding Bird Survey shows a 61% rise across the UK from 1995 to 2024 and 6% over the last ten years, with rises of 79% in England and 61% in Scotland and no clear change in Wales; in Northern Ireland numbers rose 42% from 1997 to 2024, but fell 16% in the ten years to 2024.¹⁸

The increase has come with better breeding: fewer nests fail at the egg and chick stages, and laying has moved about a week earlier, probably helped by the bird's broad diet.¹ Common Birds Census data from 1964 to 1993 show numbers rose most on mixed and grazing farmland and least on arable.¹⁹

The Jackdaw is one of the birds named on general licences, which let authorised people kill or take them for set purposes: in England, preventing serious damage to livestock or crops, and safety problems with nesting birds, where users must first make reasonable efforts to solve the problem by other lawful means;^{20, 21} in Scotland, preventing serious damage and conserving wild birds;²² and in Northern Ireland, preventing serious damage or the spread of disease.²³