Grey squirrels blamed for decline in woodland birds
Grey squirrels could be causing a decline in woodland song birds,
according to a new study by the Game and Wildlife Conservation Trust.
The study over two years looked at ten woodlands where greys were being culled and
another 10 where the squirrel population was allowed to thrive.
The report found that in the woods where grey squirrels were controlled open nesting
woodland birds like wrens, robin, thrushes, blackbirds, some of the common warblers and blackcap had more
Prof Nick Sotherton of the Game & Wildlife Conservation Trust, said grey
squirrels, that eat the eggs of woodland birds, have a “case to answer”.
“The study indicated when grey squirrels were at a relatively high density and were
then removed there was a measurable positive effect on the post nesting fledging of the woodland bird
community,” he said.
George Farr, Chairman of the European Squirrel Initiative who commissioned the
research, said the study was proof that greys are contributing to the fall in number of woodland
Grey squirrels, that were introduced from the US in the late 19th Century,
have also been blamed for driving out reds, because they are bigger and spread disease.
Woodland birds have declined by 19 per cent since 1994.
Graham Madge of the RSPB agreed grey squirrels may be a factor alongside
invasive deer such as muntjacs eating low branches and shrubs so that birds such as nightingales cannot
But he said the population was too established to drive out. Instead he
suggested woodland coverage should be increased and woods managed better to encourage woodland birds.
“There are a number of factors blamed for the decline of woodland birds. It
is squirrels, deer, drying out of woodlands as water tables fall. The potential for a non-native squirrel like grey
squirrels could cause alarm," he said. "We have to look at further research."
Louise Gray, Environment Correspondent
28th February 2012