Jackdaw
The Western Jackdaw, also known as the Eurasian Jackdaw, European Jackdaw or simply Jackdaw, is a passerine bird in the crow family.
Measuring 13 to 15 inches in length, the Jackdaw is the second smallest member of the crow family. Most of the plumage is a shiny black with a purple or blue sheen on the crown, forehead and secondaries and a green-blue sheen on the throat, primaries and tail. The cheeks, nape and neck are light grey to greyish-silver and the underparts are slate-grey. The legs are black as is the short stout bill. The irises of adults are greyish or silvery white while those of juveniles are light blue, becoming brownish before whitening at around one year of age. The sexes look alike although the head and neck plumage of male birds fades more with age and wear, particularly just before moulting. Immature birds have duller and less demarcated plumage. The head is a sooty black, sometimes with a faint greenish sheen and brown feather bases visible, the back and side of the neck are dark grey and the underparts greyish or sooty black. The tail has narrower feathers and a greenish sheen. There are 4 recognised geographical subspecies of the Jackdaw, each with slight plumage variations.
Within its range, the Jackdaw is generally unmistakable and its short bill and grey nape are distinguishing features. In flight, the Jackdaw is distinguishable from other crows by its smaller size, faster and deeper wingbeats and proportionately narrower and less fingered wing tips. It also has a shorter and thicker neck and a much shorter bill and it frequently flies in tighter flocks.
The Jackdaw is a skilled flyer and can manoeuvre tightly as well as tumble and glide. It has characteristic jerky wing beats when flying. On the ground, the Jackdaw has an upright posture and struts briskly with its short legs giving it a rapid gait.
The Jackdaw is found from north west Africa, throughout all of Europe, except for the extreme north, and east through central Asia to the east Himalayas and Lake Baikal. To the east, it occurs throughout Turkey, the Caucasus, Iran, Iraq, Afghanistan, Pakistan and north west India. A small number of Jackdaws reached the north east of North America in the 1980s and have been found from Atlantic Canada to Pennsylvania. The range is vast and there is a large global population.
Most populations are resident but the north and east populations are more migratory and relocate to wintering areas between September and November and return between February and early May.
The Jackdaw can be found in wooded steppes, pastures, cultivated land, coastal cliffs and towns. It thrives when forested areas are cleared and converted to fields and open areas. Habitats with a mix of large trees, buildings and open ground are preferred. Open fields are left to the Rook and more wooded areas to the Jay.
The Jackdaw is highly gregarious and is generally seen in flocks of varying sizes. Flocks increase in size in autumn and birds congregate at dusk for communal roosting with up to several thousand individuals gathering at one site. Males and females pair bond for life and pairs stay together within flocks. Jackdaws will frequently congregate with other crows such as Carrion Crows, Hooded Crows or Rooks.
Foraging takes place mostly on the ground in open areas and to some extent in trees. Landfill sites, bins, streets and gardens are also visited, more often early in the morning when there are fewer people about. Various feeding methods are employed, such as jumping, pecking, clod-turning and scattering, probing the soil and occasional digging. The Jackdaw will also ride on the backs of sheep and other mammals such as deer, seeking ticks as well as actively gathering wool or hair for nests.
Compared with other crows, the Jackdaw spends more time exploring and turning over objects with its bill. It also has a straighter and less downturned bill and increased binocular vision which are advantageous for this foraging strategy.
The Jackdaw is opportunistic and highly adaptable and varies its diet markedly depending on available food sources. It tends to feed on small invertebrates that are found above ground, including various species of beetle as well as snails and spiders. It will also eat small rodents, bats, the eggs and chicks of birds and carrion such as roadkill. Vegetable items consumed include farm grains, weed seeds, elderberries, acorns and various cultivated fruits.
The Jackdaw practices active food sharing with a number of individuals regardless of sex or kinship. It also shares more of a preferred food than a less preferred food. The active giving of food by most birds is found mainly in the context of parental care and courtship although the Jackdaw shows much higher levels of active giving than has been documented for other species. The function of this behaviour is not fully understood and several theories have been advanced.
Genetic analysis of Jackdaw pairs and offspring shows no evidence of extra-pair copulation and there is little evidence for couple separation even after multiple instances of reproductive failure. Some pairs do separate in the first few months but almost all pairings of over 6 months' duration are lifelong and end only when a partner dies. Widowed or separated birds fare badly and are often ousted from nests or territories and are unable to rear broods alone.
The Jackdaw usually breeds in colonies with pairs collaborating to find a nest site which they then defend from other pairs and predators during most of the year. It will nest in cavities in trees or cliffs, in ruined or occupied buildings and in chimneys, the common feature being a sheltered site for the nest. A mated pair usually constructs a nest by improving a crevice by dropping sticks into it. The nest is then built on top of the platform formed. Nest platforms can attain a great size. Nests are lined with hair, wool, dead grass and many other materials. Clutches usually contain 4 or 5 eggs which are incubated by the female for 17 to 18 days until hatching as naked altricial chicks which are completely dependent on the adults for food. The chicks fledge after 28 to 35 days and the parents continue to feed them for another 4 weeks or so.
Date: 23rd June 2021
Location: Rhossili, Gower peninsula, Swansea
Measuring 13 to 15 inches in length, the Jackdaw is the second smallest member of the crow family. Most of the plumage is a shiny black with a purple or blue sheen on the crown, forehead and secondaries and a green-blue sheen on the throat, primaries and tail. The cheeks, nape and neck are light grey to greyish-silver and the underparts are slate-grey. The legs are black as is the short stout bill. The irises of adults are greyish or silvery white while those of juveniles are light blue, becoming brownish before whitening at around one year of age. The sexes look alike although the head and neck plumage of male birds fades more with age and wear, particularly just before moulting. Immature birds have duller and less demarcated plumage. The head is a sooty black, sometimes with a faint greenish sheen and brown feather bases visible, the back and side of the neck are dark grey and the underparts greyish or sooty black. The tail has narrower feathers and a greenish sheen. There are 4 recognised geographical subspecies of the Jackdaw, each with slight plumage variations.
Within its range, the Jackdaw is generally unmistakable and its short bill and grey nape are distinguishing features. In flight, the Jackdaw is distinguishable from other crows by its smaller size, faster and deeper wingbeats and proportionately narrower and less fingered wing tips. It also has a shorter and thicker neck and a much shorter bill and it frequently flies in tighter flocks.
The Jackdaw is a skilled flyer and can manoeuvre tightly as well as tumble and glide. It has characteristic jerky wing beats when flying. On the ground, the Jackdaw has an upright posture and struts briskly with its short legs giving it a rapid gait.
The Jackdaw is found from north west Africa, throughout all of Europe, except for the extreme north, and east through central Asia to the east Himalayas and Lake Baikal. To the east, it occurs throughout Turkey, the Caucasus, Iran, Iraq, Afghanistan, Pakistan and north west India. A small number of Jackdaws reached the north east of North America in the 1980s and have been found from Atlantic Canada to Pennsylvania. The range is vast and there is a large global population.
Most populations are resident but the north and east populations are more migratory and relocate to wintering areas between September and November and return between February and early May.
The Jackdaw can be found in wooded steppes, pastures, cultivated land, coastal cliffs and towns. It thrives when forested areas are cleared and converted to fields and open areas. Habitats with a mix of large trees, buildings and open ground are preferred. Open fields are left to the Rook and more wooded areas to the Jay.
The Jackdaw is highly gregarious and is generally seen in flocks of varying sizes. Flocks increase in size in autumn and birds congregate at dusk for communal roosting with up to several thousand individuals gathering at one site. Males and females pair bond for life and pairs stay together within flocks. Jackdaws will frequently congregate with other crows such as Carrion Crows, Hooded Crows or Rooks.
Foraging takes place mostly on the ground in open areas and to some extent in trees. Landfill sites, bins, streets and gardens are also visited, more often early in the morning when there are fewer people about. Various feeding methods are employed, such as jumping, pecking, clod-turning and scattering, probing the soil and occasional digging. The Jackdaw will also ride on the backs of sheep and other mammals such as deer, seeking ticks as well as actively gathering wool or hair for nests.
Compared with other crows, the Jackdaw spends more time exploring and turning over objects with its bill. It also has a straighter and less downturned bill and increased binocular vision which are advantageous for this foraging strategy.
The Jackdaw is opportunistic and highly adaptable and varies its diet markedly depending on available food sources. It tends to feed on small invertebrates that are found above ground, including various species of beetle as well as snails and spiders. It will also eat small rodents, bats, the eggs and chicks of birds and carrion such as roadkill. Vegetable items consumed include farm grains, weed seeds, elderberries, acorns and various cultivated fruits.
The Jackdaw practices active food sharing with a number of individuals regardless of sex or kinship. It also shares more of a preferred food than a less preferred food. The active giving of food by most birds is found mainly in the context of parental care and courtship although the Jackdaw shows much higher levels of active giving than has been documented for other species. The function of this behaviour is not fully understood and several theories have been advanced.
Genetic analysis of Jackdaw pairs and offspring shows no evidence of extra-pair copulation and there is little evidence for couple separation even after multiple instances of reproductive failure. Some pairs do separate in the first few months but almost all pairings of over 6 months' duration are lifelong and end only when a partner dies. Widowed or separated birds fare badly and are often ousted from nests or territories and are unable to rear broods alone.
The Jackdaw usually breeds in colonies with pairs collaborating to find a nest site which they then defend from other pairs and predators during most of the year. It will nest in cavities in trees or cliffs, in ruined or occupied buildings and in chimneys, the common feature being a sheltered site for the nest. A mated pair usually constructs a nest by improving a crevice by dropping sticks into it. The nest is then built on top of the platform formed. Nest platforms can attain a great size. Nests are lined with hair, wool, dead grass and many other materials. Clutches usually contain 4 or 5 eggs which are incubated by the female for 17 to 18 days until hatching as naked altricial chicks which are completely dependent on the adults for food. The chicks fledge after 28 to 35 days and the parents continue to feed them for another 4 weeks or so.
Date: 23rd June 2021
Location: Rhossili, Gower peninsula, Swansea
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Also in: Crows
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