The descriptive text, below the map, is from the Cornish Red Data Book (2009). The map on this web page depicts the organisms distribution and shows the records made pre-2000 and those made since.
Range & Status
Distributed widely across the Palaearctic: from Ireland and Spain in the west, to Korea and Kamchatka in the east (Harris & Yalden, 2008). In Britain, Red Squirrel is replaced by the introduced, North American, Grey Squirrel Sciurus carolinensis in most of England and Wales (Corbet & Harris, 1996). It has, however, survived in southern England on Brownsea and Furzey Islands (Dorset) and on the Isle of Wight, and thrives on Jersey, in the Channel Islands, following its introduction there in the 19th Century. Some isolated populations are still present, in addition, in Wales, Lancashire, north Yorkshire and Durham and it is still abundant in north Cumbria, Northumberland, large parts of Scotland and Ireland. With the exception of Arran and Bute, Red Squirrel is absent from most Scottish Islands (Harris & Yalden, 2008). Harris et al . (1995) give a total pre-breeding population estimate of 121,000 for Scotland, 30,000 for England and 10,000 for Wales.
Last recorded in Cornwall at St. Ives (SW54) harbour in 1983 and at Tresillian (SW84) in 1984, Red Squirrel is now extinct in Cornwall (with the occasional sighting of the odd released/escaped animal). Most records were for the west of Cornwall, notably areas bordering the River Fal (SW84), and south of St. Ives Bay (SW53). In east Cornwall there were a few records for the Caradon District (SX25, SX45), and south and west of the Camel Estuary (SW87, SW97). A map of post-1960 records (Turk, 1973) shows presence in most Cornish 10km x 10km squares except for the tips of The Lizard and West Penwith, and on the south-west side of the River Tamar.
Habitat & Ecology
Found, throughout most of its Palaearctic range, in coniferous forests of Scots Pine Pinus sylvestris , Norway Spruce Picea abies and Siberian Pine Pinus cembra . In south and west Europe it is also found in broadleaved woodland. The most stable populations in Britain are found in large tracts of coniferous forest over 25 years old. The species is also found in small woods and copses where the Grey Squirrel is not present (Corbet & Harris, 1996). Red Squirrel is more arboreal than Grey Squirrel, spending 70% of the time off the ground. Hazel Corylus avellena nuts are important in deciduous woodland habitat (Harris et al .,
1995). Habitat use varies with time of year in relation to food availability (Harris & Yalden, 2008). Red Squirrel will readily use gardens and is found in urban areas in Europe (Harris & Yalden, 2008).
Competitive exclusion by Grey Squirrel is the greatest threat; particularly in deciduous woodland, where Grey Squirrel live at higher densities than Red Squirrel. In some situations the two species can co-exist for 20 years but generally populations of Red Squirrel declines when Grey Squirrel colonises an area (Harris et al ., 1995). Feeding competition alone could explain the replacement of Red Squirrel. The situation has been exacerbated by the
post-war decline in coppiced Hazel. A Red Squirrel is unable to accumulate fat deposits in times of plenty and, in addition, is not able to digest acorns (Morris, 1993). Spending most of the time in the tree canopy, Red Squirrel need continuous tree cover, thus are vulnerable to habitat fragmentation (Harris et al ., 1995). In addition, some populations of Grey Squirrel harbour Squirrel Pox Virus (formally known as Parapoxvirus) which has been found in Red Squirrel. It is now believed that this has been a major factor in the decline of Red Squirrel in Britain. Although not lethal to Grey Squirrel, it is fatal to Red Squirrel which typically die after about 15 days. At the time of writing this account, there has been a recent outbreak of this disease in the Ainsdale and Formby areas of West Lancashire, where 48 dead Red Squirrel have been found (Brown, 2008).
It seems highly unlikely that the Red Squirrel could be re-established in Cornwall without a huge amount of commitment and resources to create suitable habitat. The continuous control of Grey Squirrel numbers would also be needed as the Red Squirrel can, probably, only compete with Grey Squirrel in large, mixed, mature, coniferous woodlands as it does in Scotland. Morris (1993) suggests the possibility of designing suitable nest-boxes to help this species. The Red Squirrel is protected from trapping, shooting and all forms of interference being l
I.J. Bennallick, S. Board, C.N. French, P.A. Gainey, C. Neil, R. Parslow, A. Spalding and P.E. Tompsett. eds. 2009. Red Data Book for Cornwall and the Isles of Scilly. 2nd Edition.Croceago Press.
The Cornish Red Data Book Project was led by the Cornwall and Isles of Scilly Federation for Biological Recorders (CISFBR). The full text and species accounts (minus the maps) are available on the CISFBR website.