The Song Thrush is a small to medium sized member of the thrush family, being smaller than Blackbird, slightly larger than a Redwing and about 15% smaller than a Mistle Thrush. Song Thrushes usually have warm-brown upperparts, although some individuals show colder tones more akin to those seen on the Mistle Thrush. The underparts are predominantly white, with a warm brown-buff wash on the sides, which extends and strengthens in colour under the wing (this is distinct from the strong red-brown colour seen in the Redwing). The brown spots on the underparts tend to arranged in lines on the flanks. The tail is proportionally shorter than in the Mistle Thrush and lacks any obvious white colouration.
The song consists of a series of vigorous, simple phrases, less rich than that of the Blackbird, but with a penetrating quality. The fluting notes are often interspersed with harsh, impure tones and some mimicry of other species.
Song Thrushes can be very early nesters and the young may be on the wing by the end of March in a good season. In common with other thrushes, mud is incorporated into the nest but the Song Thrush does not bother with a grass lining – she lays her lovely blue eggs onto a smooth mud inner surface which makes their nests quite easy to recognise.
Careful analysis of BTO ring-recoveries has shown that poor survival of young birds through their first winter could explain the observed drop in the Song Thrush population. Between 1962 and 1973, winter survival probability for first year birds was 48.4% compared to only 40.5 between 1975 and 1993 – a drop of nearly 20%. There does not seem to be any comparable decline in nest productivity or in the survival rate of adult birds once they have made it through this winter bottleneck.
As a garden bird, the Song Thrush is most likely to be seen alone or in pairs, although during the winter, groups may feed alongside Blackbirds, Redwings and Fieldfares. Song Thrushes are usually seen feeding on the ground, or heard smashing snails against stones. The flight is typically fast and direct and may be accompanied by a short call note.
Understanding Curlew populations in Wales
Several tracking projects combine to determine the migration routes, wintering locations and breeding season movements of Welsh Curlew.