National Species Action Plan
as well as the Sussex Arable Land, Chalk
Grassland, Hedgerows, Urban
and Woodland Habitat Action Plans will
be used to implement and monitor action for the song thrush in Sussex.
is a common and widespread species, which is declining throughout
the UK. It is a partial migrant and also an abundant passage migrant,
with large numbers of Continental breeders overwintering in the
UK and with many birds, which breed in the UK, wintering further
south in Europe. These birds are generally more abundant in the
east than the west of the country.
song thrush population is estimated at 1.1 million breeding pairs
(The State of the UK's birds, 2001). Following the winter of 1962/63
the population declined, but recovered to a stable level within
three to four years. The numbers subsequently remained stable until
the mid 1970s, after which they declined steadily. RSPB research
shows that, between 1972 and 1996, there was a 66% decline in song
thrush numbers on farmland and 39% decline in woodland habitats.
song thrush is protected under the EC Birds Directive, the Wildlife
& Countryside Act 1981 and the Wildlife (Northern Ireland) Order
1985. It is a Red List species (high conservation concern) in Birds
of Conservation Concern: 2002-2007.
Current Status in Sussex
thrush numbers have declined less in the south east of Britain than
most other areas. In Sussex, the song thrush is an abundant resident
across the county and partial migrant; abundant passage migrant
and very common winter visitor.
thrush densities are highest in the Weald. They are relatively scarce
breeders in open downland even where there is scrub. They have a
similar distribution to mistle thrushes in Sussex. Song thrushes
appear to perform reasonably well in urban/suburban areas, where
there is a relatively low level of pesticide use and good availability
of feeding and nesting sites - although the domestic cat is a serious
the mid 1970s, Shrubb (1979) considered that song thrush numbers
were increasing. Since then, a steady national decline has been
reflected in Sussex. Shrubb estimated an average of 24 pairs per
km2 on Sussex farmland. Censuses in various habitats during the
1980s gave a combined average of less than 9 pairs per km2 . Assuming
that these figures apply to the whole county, the Sussex breeding
population can be estimated at 35,000 pairs. This is likely to fluctuate
in response to mild or severe winters.
percentage of Sussex breeding birds that emigrates for the winter
is not known and may vary. Song thrushes from the continent pass
through Sussex in autumn, particularly along the Downs and at the
coast. Both route and destination are clearly shown by ringing recoveries:
across the Channel, down the Atlantic coast of France and into western
Spain and Portugal, where many are shot. Other migrants arrive in
the autumn from the Low Countries, Germany, Denmark and maybe Norway.
Song thrushes are badly affected by severe weather, as in early
1985, when they were seen flying west at the rate of 200 an hour
at Saltdean on 7th January. (SOS 1996).
Current Factors Causing Loss or Decline [top]
species is covered in the Sussex Arable Land Habitat Action Plan
as it has suffered greatest decline in agricultural areas.
Reasons for the decline in song thrush numbers are poorly understood,
but may relate to the following factors:
· Changes in farming affecting food supply and the availability
of nest sites, particularly the switch from spring to autumn sowing
of cereals and possibly increased use of pesticides.
· Severe winter weather and dry soil conditions in late summer
affect food supply. Not enough young are raised to offset normal
winter mortality, resulting in rapid population decline.
· Song thrush prey inhabit damp grassland, ditches, scrub
and woodland. The loss of key feeding habitats and the consequent
reduction in the availability of invertebrates, is probably the
main reason why these birds are failing to raise enough broods each
year. Woodland and grazed grassland in the preferred habitat. Cereal
land is avoided.
· Predation by corvids and foxes.
· Song thrushes are a favourite prey of sparrowhawks. The
resurgence of this predator in Sussex since the 1960s cannot have
· Competition with blackbirds.
· Hunting in southern Europe.