Coal tit

Appearance

The coal tit is 10–11.5 cm in length, and has a distinctive large white nape spot on its black head. The head, throat and neck of the adult are glossy blue-black, setting off the off-white sides of the face and the brilliant white nape; the white tips of the wing coverts appear as two wingbars. The underparts are whitish shading through buff to rufous on the flanks. The bill is black, the legs lead-coloured, and irides dark brown.

The young birds are duller than the adults, lacking gloss on the black head, and with the white of nape and cheeks tinged with yellow.

While searching for food, coal tit flocks keep contact with incessant short "dee" or "see-see" calls. The species' song – if "song" it can be called – is a strident "if-he, if-he, if-he", heard most frequently from January to June, but also in autumn. One variant of this song ends with a sharp "ichi". North African birds also have a "currr" call similar to that of the European crested tit which is not found in Africa.

Naming

A number of coal tit subspecies are distinguished. The differences in coloration are quite pronounced in some of them, while their differences in size are more subtle. Coal tits from Asia follow Bergmann's rule, being larger in colder regions; those from further west, however, do not, as the birds from the uplands around the Mediterranean are larger than those from northern Europe. Across its range, tail length in relation to body length increases along a cline running from southwest to northeast.

The British race "P. a. britannicus" has an olive hue to its brownish-grey back plumage, distinguishing it from the continental European nominate subspecies "P. a. ater" and "P. a. abietum" in which the back is bluish grey without a hint of green or brown. The Irish race "P. a. hibernicus" is distinguished from "britannicus" by the pale sulphur-yellow cheeks, breast and belly. It also has a paler rump and a larger bill than its relatives from Britain and the Continent.

The North African race "P. a. ledouci" has yellow underparts and cheeks, and the Cypriot "P. a. cypriotes" has a buff tinge to its upperparts, and deep buff underparts. Asian subspecies are generally rather dusky brownish except for the black-and-white head; they include among others "P. a. michalowskii" of the Caucasus, "P. a. phaeonotus" of Iran, or the Himalayan coal tit "P. a. aemodius" of southwestern China.

Behavior

It is typically a bird of temperate humid conifer forest, but apart from that shows little habitat specificity. In Bhutan for example coal tits are fairly common residents above the subtropical zone, at about 3,000-3,800 m ASL, and are found in forests dominated by Bhutan Fir as well as in those characterized by Himalayan Hemlock and rhododendrons.

The coal tit is an all-year resident throughout almost all range, making only local movements in response to particularly severe weather; only the Siberian birds have a more regular migration. Very rarely, vagrants may cross longer distances; for example the nominate subspecies of continental Europe was recorded in Ireland once in 1960 and once before that, but apparently not since then.

Coal tits will form small flocks in winter with other tits. This species resembles other tits in acrobatic skill and restless activity, though it more frequently pitches on a trunk, and in little hops resembles a treecreeper. Its food is similar to that of the others; it is keen on beechmast, picks out the seeds from fir and larch cones, and joins "Carduelis" redpolls and siskins in alders and birches. It will also visit gardens to feed on a variety of foods put out, particularly sunflower seeds.

A favourite nesting site is a hole in a rotting tree-stump, often low down, and the nest is deep within the hole; holes in the ground, burrows of mice or rabbits, chinks between the stones in walls, old nests of "Pica" magpies or other large birds, and squirrel dreys are also occupied. The materials, moss, hair and grass, are closely felted together, and rabbit fur or feathers added for lining. Seven to eleven red-spotted white eggs of the usual tit type are laid, usually in May; this species breeds usually once per year.

Being common and widespread, the coal tit is not considered a threatened species by the IUCN.

Habitat

It is typically a bird of temperate humid conifer forest, but apart from that shows little habitat specificity. In Bhutan for example coal tits are fairly common residents above the subtropical zone, at about 3,000-3,800 m ASL, and are found in forests dominated by Bhutan Fir as well as in those characterized by Himalayan Hemlock and rhododendrons.

The coal tit is an all-year resident throughout almost all range, making only local movements in response to particularly severe weather; only the Siberian birds have a more regular migration. Very rarely, vagrants may cross longer distances; for example the nominate subspecies of continental Europe was recorded in Ireland once in 1960 and once before that, but apparently not since then.

Coal tits will form small flocks in winter with other tits. This species resembles other tits in acrobatic skill and restless activity, though it more frequently pitches on a trunk, and in little hops resembles a treecreeper. Its food is similar to that of the others; it is keen on beechmast, picks out the seeds from fir and larch cones, and joins "Carduelis" redpolls and siskins in alders and birches. It will also visit gardens to feed on a variety of foods put out, particularly sunflower seeds.

A favourite nesting site is a hole in a rotting tree-stump, often low down, and the nest is deep within the hole; holes in the ground, burrows of mice or rabbits, chinks between the stones in walls, old nests of "Pica" magpies or other large birds, and squirrel dreys are also occupied. The materials, moss, hair and grass, are closely felted together, and rabbit fur or feathers added for lining. Seven to eleven red-spotted white eggs of the usual tit type are laid, usually in May; this species breeds usually once per year.

Being common and widespread, the coal tit is not considered a threatened species by the IUCN.