Although common, song thrushes have suffered dramatic
declines in recent years and are now officially 'threatened'.Sometimes
mistaken for female blackbirds, song thrush are similar in shape
but smaller with warm brown upper parts and a pale, heavily spotted
underside with buff under wings. Like its name suggests, the song
thrush is perhaps best known for its tune which is delivered from
a prominent perch, often before dawn during spring. No two have
the same repertoire.
The birds are widespread, breeding from western Ireland
through most of Europe, including Scandinavia, into Siberia as far east
as Lake Baikal. In the north and east they are highly migratory, heading
west and south during autumn. Many of these arrive in Britain from the
end of September. Many of our birds, too, head south to escape the freeze.
The birds, their eggs and nests are protected in Britain and other European
countries but illegal hunting still continues. Sadly, some birds ringed
in Suffolk have ended up shot for the pot in Portugal.
Conifer and broad-leaved woods, mixed farmland with hedges
and gardens are the song thrushes' favourite haunts. Breeding takes
place from March until July with two, three or even four broods a season
hatching from three to five black-spotted blue eggs. Incubation takes
around 13 days, and the young are tended by both parents for a further
10 to 17 days before fledging. The adults continue to feed the chicks
for about 22 days until they are independent.
Diet includes fruits and berries,
worms, insects and most importantly, slugs and snails which are tackled
by pounding the shell on a specially selected stone or 'anvil'. Different
objects are used and there is a record from Suffolk, of a song thrush
trying to smash snails on a tennis ball! Snails are important s they
provide vital food in times of drought and in cold snaps when other
sources are hard to come by.
Since the 1970s studies have
shown an accelerated drop in numbers by up to 70% in some areas. Farmland
seems to be the most severely affected but the reason why is unclear.
Widespread use of chemicals and the general "tidying-up" of
the countryside may have taken their toll. Studies have also shown that
adults make as many nesting attempts as they did before the decline,
with as many young fledging. But it is the dramatically lower survival
rate through the first winter that seems to be driving the decline.
Droughts have made food more scarce, however declines are far from uniform
across habitats. Surprisingly, suburban areas and villages have seen
hardly any changes compared to woodland and open farmland. A recent
Suffolk Wildlife Trust survey of birds using school grounds has borne
this out with nearly half the schools taking part, recording thrushes
on their premises.
Song thrushes aren't extinct
in the UK yet, but time is running out. As individuals we can
make a difference. Fruit (especially apples), meal worms and grated
mild cheese should be laid out all year round in places away from the
main bird table. (Song thrushes are timid and at the lower end of the
pecking order, often being chased off by more aggressive species). Supply
water for drinking and bathing, especially in summer. Leave fallen leaves
under bushes and trees during the winter and build a compost heap, as
these provide homes for insects which will be eaten in cold weather.
Most importantly of all, don't kill slugs and snails as these are a
life-line in harsh conditions.
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