Grey squirrel virus wiping out reds
By Jeremy Lovell
LONDON (Reuters) – Britain’s native red squirrels, already
in headlong retreat, are being wiped out not just by
competition for resources with non-indigenous gray squirrels
but from a virus the grays carry, research showed on Monday.
The squirrel poxvirus is harmless to the grays but kills
reds within two weeks of contact, said the researchers from
Newcastle University and Queen Mary, University of London among
In the absence of a vaccine, they proposed killing gray
squirrels that enter the few and rapidly shrinking areas in
Britain where red squirrels are still found.
“It is vital we get this disease under control, especially
as it is now threatening to spread across the border to
Scotland with severe consequences for red squirrel conservation
there,” said Peter Lurz of Newcastle University’s Institute for
Research on Environment and Sustainability.
“We are not trying to wipe out the gray squirrel but as
conservationists we have a duty to look after the red squirrel
as it is a protected, native species.
The disease entered the country with the gray squirrels
when they were brought into Britain 100 years ago from America
to curb the red population — traces of which can be found
dating back at least 10,000 years.
The grays have been devastatingly effective — although
until now it has been attributed to their simply muscling the
smaller reds out of the way.
In 1940, reds covered most parts of Britain. But by 1998
they had been squeezed back primarily to the Isle of Wight in
the south and Scotland, outnumbered 66 to 1.
The researchers said that unless action was taken promptly,
even the few remaining reds could be wiped out in some areas
within a decade.
“Given that the gray squirrel is an introduced species, and
therefore the disease has occurred as a consequence of human
action, the onus is very much on us to look for practical
solutions to control the disease and protect red squirrels from
(it),” said Tony Sainsbury, lecturer in wild animal health at
the Zoological Society of London.
“Our work concludes that targeted control is the most
viable way forward.