1-10-2016 CHELMSFORD, ESSEX - SONG THRUSH (Turdus philomelos)

The song thrush (Turdus philomelos) is a thrush that breeds across the West Palearctic. It has brown upper-parts and black-spotted cream or buff underparts and has three recognised subspecies. Its distinctive song, which has repeated musical phrases, has frequently been referred to in poetry.

The song thrush breeds in forests, gardens and parks, and is partially migratory with many birds wintering in southern Europe, North Africa and the Middle East; it has also been introduced into New Zealand and Australia. Although it is not threatened globally, there have been serious population declines in parts of Europe, possibly due to changes in farming practices.

The song thrush builds a neat mud-lined cup nest in a bush or tree and lays four to five dark-spotted blue eggs. It is omnivorous and has the habit of using a favourite stone as an "anvil" on which to break open the shells of snails. Like other perching birds (passerines), it is affected by external and internal parasites and is vulnerable to predation by cats and birds of prey.

The song thrush breeds in most of Europe (although not in the greater part of Iberia, lowland Italy or southern Greece), and across Ukraine and Russia almost to Lake Baikal. It reaches to 75°N in Norway, but only to about 60°N in Siberia. Birds from Scandinavia, Eastern Europe and Russia winter around the Mediterranean, North Africa and the Middle East, but only some of the birds in the milder west of the breeding range leave their breeding areas.

In Great Britain song thrushes are commonly found where there are trees and bushes. Such areas include parks, gardens, coniferous and deciduous woodland and hedgerows.

Birds of the nominate subspecies were introduced to New Zealand and Australia by acclimatisation societies between 1860 and 1880, apparently for purely sentimental reasons. In New Zealand, where it was introduced on both the main islands, the song thrush quickly established itself and spread to surrounding islands such as the Kermadecs, Chatham and Auckland Islands. Although it is common and widespread in New Zealand, in Australia only a small population survives around Melbourne. In New Zealand, there appears to be a limited detrimental effect on some invertebrates due to predation by introduced bird species, and the song thrush also damages commercial fruit crops in that country. As an introduced species it has no legal protection in New Zealand, and can be killed at any time.

The song thrush is not usually gregarious, although several birds may roost together in winter or be loosely associated in suitable feeding habitats, perhaps with other thrushes such as the blackbird, fieldfare, redwing and dark-throated thrush. Unlike the more nomadic fieldfare and redwing, the song thrush tends to return regularly to the same wintering areas.

This is a monogamous territorial species, and in areas where it is fully migratory, the male re-establishes its breeding territory and starts singing as soon as he returns. In the milder areas where some birds stay year round, the resident male remains in his breeding territory, singing intermittently, but the female may establish a separate individual wintering range until pair formation begins in the early spring.

During migration, the song thrush travels mainly at night with a strong and direct flight action. It flies in loose flocks which cross the sea on a broad front rather than concentrating at short crossings (as occurs in the migration of large soaring birds), and calls frequently to maintain contact. Migration may start as early as late August in the most easterly and northerly parts of the range, but the majority of birds, with shorter distances to cover, head south from September to mid-December. However, hard weather may force further movement. Return migration varies between mid-February around the Mediterranean to May in northern Sweden and central Siberia. Vagrants have been recorded in Greenland, various Atlantic islands, and West Africa.