As well as the threat of competition
from the grey squirrels, red squirrels also have to face the threat from the deadly squirrel-pox virus, otherwise known as
the Parapox virus. The origins of the virus are unknown, but it was first confirmed in East Anglia in the 1980s. Since then
there have been cases in red squirrel populations in Lancashire, Cumbria, Durham and Northumberland.
It is believed that
the grey squirrels actually act as the host and carrier for the virus, but are largely immune to its effects. Only one case
of the disease in a grey squirrel has ever been found. This is due to the antibodies that the grey produces to defeat the
virus, which are not produced in the red squirrel. Those reds that are infected develop skin ulcers, lesions and scabs with
swelling and discharge around the eyes, mouth, feet and genitalia. Infected animals resemble rabbits with myxomatosis and
are sometimes found shivering and lethargic. Infected red squirrels usually die within one to two weeks.
It is not yet clear
how the virus is transferred. Possibilities include it being passed by fleas, ticks and mites, which may transfer from animal
to animal in the dreys.
Grey squirrels carrying
the disease are continuing to make their way northwards from the infected populations in northern Cumbria. This has already had serious implications for the red squirrels in Northumberland and the Kielder forest. In addittion
in 2005 the first evidence of the virus in southern Scotland was revealed by scientists
at the Moredun Research Institute.
If you find a recently
dead red squirrel with legions, the Joint Nature Conservation Committee (JNCC) (the statuory adviser to the Government on
UK and international nature conservation) advices you to make contact with the Institute of Zoology.
They also provide information on how to help the Institute identify and further research potential areas of the epidemic on
the following site:
http://www.jncc.gov.uk/pdf/rs_disease.pdf
