Mistle thrush

The mistle thrush (Turdus viscivorus) is a large member of the thrush family that is commonly seen in the United Kingdom, and is often regarded as a herald of spring because it arrives at its breeding grounds, and starts singing, as early as late February in some areas. It is also widely distributed throughout Europe and into northern Africa, the Middle East and western Asia.

During the breeding season, mistle thrushes generally confine themselves to forest margins and clearings, but in late summer and autumn they will roam the countryside in flocks. Those birds that over-winter in the UK will often move to fields and moors. Others migrate south and west.

Appearance

The mistle thrush is some 26-28 centimetres (10.5-11 inches) in length. It is therefore larger than the song thrush and is deeper-chested with longer wings and tail. The mistle thrush is an aggressive and powerful bird that stands upright and hops across the ground. When standing it lowers its tail and droops its wings. It resembles the fieldfare in its general appearance and behaviour.

Plumage is similar as between males and females, and is also similar to that of the song thrush. However, the upperparts of the mistle thrush are noticeably greyer. The underparts are light-coloured and speckled from the throat right down to the tail. The underwings are white.


Behaviour

The mistle thrush is not found in undergrowth but often sings from treetops. Its flight is often high, with exaggerated wing-beats.

The voice is a rasping chatter. The song is not unlike that of the blackbird, but less mellow and louder and faster, with shorter pauses between the phrases.

Food consists of berries, fruit, slugs, worms and insects. Mistle thrushes will also take the nestlings of other bird species.


Breeding

The mistle thrush breeds in coniferous and mixed woods, and parkland, building its nest high in the fork of a tree. The first nest will be built towards the end of March and, for the second brood, in June. The nest consists of twigs, roots, grass and moss. The lining, supplied by the female mistle thrush, is made from mud and fine pieces of grass.

The clutch, of four or five eggs, is incubated by the hen bird alone, for up to 14 days. The young birds leave the nest at 14 to 16 days, although they will not be able to fly at this stage.


Conservation

In former times, mistle thrushes were regarded as game birds, possibly because they made attractive targets for marksmen as they announced their presence high in the trees. However, they are now protected and their numbers are keeping up fairly well. Despite this, the mistle thrush remains an “amber list” species in the UK.

© John Welford