Joyful song of a welcome garden visitor
The dappled Song thrush, with its distinctive melody, has been celebrated by poets for centuries and remains a favourite of nature lovers and gardeners
“At once a voice arose among The bleak twigs overhead In a full-hearted evensong Of joy illimited”
Thomas Hardy, ‘The Darkling Thrush’
It is an Hour before dawn on a cold and frosty February morning, but, despite the frigid air, a handful of birds are beginning to sing, to herald the new day. Soon, the lightening blue of the sky will be streaked with a tangerine glow as the sun begins its rise over the horizon. At this time of year, with approximately a month until the spring equinox, the days are rapidly becoming longer. It may still feel wintry, but the breeding season is getting under way.
One of the birds marking out its territory through singing is the aptly named Song thrush. Like other songbirds, it sings for two closely related reasons: to repel rival males, and to attract females. It will need to do this almost constantly; well into the spring and early summer if it is to have the chance to breed and raise a family.
The Song thrush is approximately 9in (23cm) long, with a 131/2in (34cm) wingspan and weighs an average of 85g (3oz). Like many other thrushes, it has a distinctively marked breast, with brown or blackish spots on a creamy-white background; warm-brown upper parts, and an unmarked face, with beady, black eyes. It has lengthy, springy legs and a longish, narrow bill, which it uses to obtain food by probing into grassy lawns. The posture is alert and fairly upright. Males and females, which are generally monogamous, are alike in appearance.
Wide-ranging species
The Song thrush is found widely across most of Europe, apart from the far south, and also in North Africa, the Middle East and into western Asia; north to way beyond the Arctic Circle in Norway. In the late 19th century, they were misguidedly introduced to New Zealand, where they continue to thrive, and Australia, where, apart from a tiny population in Melbourne, they have almost disappeared. Northern European and Asian populations migrate, while those that breed in Britain are mainly sedentary, though Scottish thrushes do head across the Irish sea to Ireland, and some English birds cross the Channel to France. Some birds from Scandinavia also pass through Britain each autumn and spring. Song thrushes can be seen across most of Britain, apart from the high tops of the Scottish Highlands. Birds in the Hebrides belong to a different race, and in the absence of suitable trees and bushes, often nest on the ground.
Changing habitat
Like so many garden birds, including the blackbird, robin and various species of tit, Song thrushes originally evolved as birds of woods and forests. However, in the past century or more, they have adapted well to life alongside people; finding a home in gardens, town and city parks, and along hedgerows in more open countryside.
Studies of habitat use in England have revealed that more than 70 per cent of Song thrushes now nest in gardens, even though these make up just two per cent of total land area, and that they do so at densities several times greater than in their ‘natural’ habitat. The rise of modern industrial farming, with the consequent loss of hedgerows and reduced availability of insect food, means that only a small proportion of Song thrushes now nest on farmland.
In autumn and winter, however, while most male Song thrushes remain in their breeding territory, females and youngsters often move out of gardens, parks and wooded areas, and forage for food in more open countryside.
The Song thrush has one of the most distinctive songs of any British bird, thanks to its habit of repeating short phrases two or three times, before moving onto a new one; giving the listener the impression that the bird is holding a rather one-sided conversation. Like other common songbirds, such as the blackbird and robin, Song thrushes usually sing from dawn to dusk during late winter and early spring. They will also sing at night, especially when several birds are kept awake by street lights, and begin singing as a territorial response to one another.
Varied diet
For most of the year, Song thrushes feed mainly on earthworms, pulling them from the soil using their pointed bill. But they also regularly feed on other invertebrates, such as butterfly and moth caterpillars, slugs and beetles. In late summer and autumn, they supplement their diet with fruits, especially windfall apples, and berries, including elderberries and haws. In summer, especially if the weather is too dry for them to obtain worms easily from the hard, sun-baked soil, they will seek out snails. Once they find one, they will bash the hard shell on a handy stone or rock, known as an anvil, to get at the juicy creature inside.
Breeding and nesting
In early spring, once the male has managed to attract a female, she gets down to the hard work of building a nest. The Song thrush’s nest is a circular cup, constructed out of neatly woven small twigs, moss, dead leaves and grass, and lined with a thin layer of mud. The typical nest site is usually in a hedgerow, bush or tree, or sometimes hidden by the ivy around a tree trunk, and between 3-13ft (1-4m) above the ground, where it will not be easily seen or disturbed.
When the nest is finished, the female will lay a clutch of between two and six eggs, one per day, before starting incubation. The eggs are a distinctive pale blue in colour and lightly speckled with darker spots, mostly concentrated at the larger end of the egg.
The eggs are then incubated for 13-15 days, mainly, although not exclusively, by the female. Once the eggs have hatched, both parents find food for the chicks, bringing back small insects and invertebrates. Although, like other songbirds, baby thrushes are born naked, blind and fairly helpless, they do grow very rapidly, and their initial covering of thin down is soon replaced by feathers.
“How true she warped the moss to form a nest, And modelled it within with wood and clay; And by and by, like heath-bells gilt with dew, There lay her shining eggs, as bright as flowers, Ink-spotted over shells of greeny blue”
John Clare, ‘The Thrush’s Nest’
The young fledge and leave the nest after a further 12-16 days, even though they are still noticeably smaller than the adults at this stage. They will stay with one or other parent for a few days afterwards. Once the young become independent, the pair usually attempt a second brood, and occasionally, especially in the southern part of their range, a third. Song thrushes are very early nesters; sometimes starting to lay their first clutch as early as February, though more commonly not until April. In very mild winters, they may even attempt to breed before Christmas, although this is usually unsuccessful, as a spell of bad weather means they are unable to find food for their hungry chicks. Nests may also fail as a result of being predated upon by jays, magpies, cats or grey squirrels.
Like other garden birds, even once they leave the comparative safety of the nest, young Song thrushes are very vulnerable to being caught and eaten by predators; notably domestic cats, but also sparrowhawks and Little owls. As a result, they have less than a 50:50 chance of reaching their first birthday. Once they reach adulthood, they will have slightly better odds of survival; typically living for approximately 3-4 years, though the oldest recorded ringed bird reached more than 11 years of age.
Celebrated songbird
Its distinctive song has contributed to the Song thrush’s popularity, where it rivals the blackbird and robin, and it has made frequent appearances in English poetry, including the writings of Ted Hughes, Thomas Hardy, Robert Browning and Gerard Manley Hopkins. Song thrushes are also celebrated in many other cultures. Their scientific name, Turdus philomelos, refers to the Ancient Greek myth of Philomel, who had her tongue cut out as a punishment and was turned into a songbird. In some versions of the tale, this was a thrush; in others, it was a nightingale. Other names for the species include ‘throstle’, from the Old English, and ‘mavis’, originally from French.
In recent years, Song thrushes have given conservationists major cause for concern. Numbers breeding in the UK have declined by approximately half during the past 50 years, and now there are just over one million breeding pairs. This appears to be caused by a reduction in the number of successfully fledged young, which, in turn, is linked to a shortage of food; probably caused by the overuse of pesticides. As a result of this population decline, the Song thrush is on the Red List of Birds of Conservation Concern, though, in the past decade, the decline appears to have slowed down and even possibly reversed, with increases reported in some areas.
Given its popularity, it is to be hoped that the species’ fortunes have now turned a corner, and in the future, the bird will be a more familiar sight and sound as it starts to sing at the end of winter and beginning of spring.