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Red squirrel (and grey squirrel, an invasive non-native species)

What action is going on for this species?

The following will give you information on what work has been taking place through the Species Action Framework:

Species background

The red squirrel (Sciurus vulgaris) is the only native squirrel species in Britain. It has characteristic ear tufts and is smaller than the introduced grey squirrel (Sciurus carolinensis). The grey squirrel may sometimes exhibit some chestnut coloration over the back and limbs, but this redness is not as uniform as in the red squirrel.

Why is this on the Species Action List?

The red squirrel satisfies criterion 1a of the Species Action Framework as a species for conservation action, primarily due to the population decline recorded over the past 50 years.  Once widespread across the UK, the species is now largely restricted to the north of England, Northern Ireland and Scotland.  Scotland currently hosts about 75% of the estimated UK population.

It has been the subject of extensive and ongoing research, with clear and targeted management actions relating to grey squirrel control and considerable public interest and associated opportunities for further biodiversity awareness.

It is a Priority Species on the UKBAP and is included on the Scottish Biodiversity List. The red squirrel is fully protected under the Wildlife and Countryside Act 1981, as amended.

The grey squirrel satisfies criterion 2 of the Species Action Framework as an invasive nonnative species. A native of North America, it was first introduced into Scotland in the late 19th century and has since expanded its range to cover much of southern and central Scotland. The species can cause damage to timber and other crops, but it is included on the Species Action List specifically because it poses a threat to the native red squirrel population.

Habitat, distribution and abundance

The red squirrel is an arboreal species.  It is largely associated with pinewoods but, in the absence of competition from grey squirrels, can exist in a more diverse, broadleaf woodland, for example in the Highlands. 

The species is distributed throughout the Palaearctic, through Europe and Scandinavia to the east coast of Russia. Populations in northern Italy are currently at risk due to the recent introduction of the grey squirrel to the Continent. 

Formerly widespread across Scotland, the species has been lost from an extensive area in the Central Belt and is found primarily in the Borders, Dumfries and Galloway, Argyll, Perthshire, Grampian and Highland. There are an estimated 160,000 red squirrels currently in the UK, of which 121,000 are in Scotland.

General ecology

The red squirrel breeds between January and September, with an average of three young per litter. It is a non-territorial species with males breeding with more than one female. Individuals may have up to eight dreys concurrently.

History of decline, contributory factors and current threats

The population of red squirrels has not always been stable and the species is reported to have become extinct in some parts of Scotland following large-scale deforestation in the 18th century.  Populations were supplemented by the introduction of red squirrels from England and Scandinavia in the early 19th century.

The three main factors threatening the conservation of red squirrels in Scotland are: spread of grey squirrels; habitat fragmentation making some areas less suitable for red squirrels, increasing their vulnerability to displacement by grey squirrels; and, disease. Red squirrels in the south of Scotland are currently under threat from the squirrelpox virus.  Research suggests that this has been introduced to the country with the grey squirrels which have an antibody immunity to the disease and show no outward symptoms of infection.  It is invariably fatal to red squirrels.

The 'Species Lead' at Scottish Natural Heritage Tel. 01463 725000

Last updated on Tuesday 19th November 2013 at 11:12 AM. Click here to comment on this page