The Red squirrel is an iconic part of Britain’s fauna and a popular species for wildlife watchers and photographers alike. This mammal has a long and somewhat juxtaposed history in the UK. Long considered a pest to forestry and actively exterminated from many plantations during the 18th and 19th centuries by “squirrel destruction clubs”, the Red squirrel took the lead role in one of Beatrix Potter’s acclaimed series of children’s books. The Tale of Squirrel Nutkin, published in August 1903, follows the exploits of “Nutkin” as he presses his luck with the Old Brown owl and was inspired by Potter’s summer holiday watching squirrels at the Lingholm estate in the Lake District in 1901.
Today, although Red squirrels enjoy a wide distribution across Europe and into Asia, their populations are suffering substantial declines in Britain such that, outside of Scotland and Ireland, only largely fragmented populations can be found in England and Wales. Many factors appear to have contributed to this decline, although the introduction of the Grey squirrel by Victorian collectors is seen as perhaps the most significant. The tireless work of conservationists is trying to tackle the decline with the aim of allowing Reds to expand their range.
The Red squirrel at a glance
Size: Max. length about 45cm (18 in.), of which up to 20cm (8 in.) may be tail. Commonly, ~ 21cm (8in.) inc. tail.
Colour: Highly variable; range from black to dull yellowy-brown (“buff”), covering most shades of red and brown. White/albino animals very rare; melanistic (black) common in some regions (e.g. continental Europe) but very uncommon in UK.
Distribution: Throughout Europe and Asia, from ~70oN to 30oN; Britain and China represent limits of range. Within UK, still reasonably widespread through northern England, southern and eastern Scotland, and much (excl. far west) of Ireland. Also found in isolated pockets of England (e.g. Brownsea Island and Isle of Wight) and three distinct populations in Wales.
Longevity: Max. (captivity) is 10 years. In wild, average is 3 yrs; max. in wild probably 7 yrs.
Sexing: Impossible at distance; during breeding season close inspection reveals swollen, darkly stained testes. Distance between genital openings can be used to sex squirrels during handling.
Activity: Diurnal (daytime) species, emerging ~30 min. after sunrise. Bimodal activity periods during the summer (morning and evening) and unimodal in winter (morning).
Dens: Referred to as “dreys”; usually in trees (occasionally on ground). Composed of leaves and twigs; lined with moss. Roughly spherical and typically 30cm (1ft.) diameter. Nursing females may have several dreys in area to facilitate moving young when threatened.
Territory: Range over ave. 70 ha (range 20-100 ha; up to 247 ac.); have “core areas” of intense use and these areas will be defended against intruders. Territory establishment essential for successful reproduction. Territory quality directly impacts fecundity.
Diet: Primarily seeds and plant matter, incl. berries and fruit. Opportunists; diet includes fungi, nuts, seeds, bark, sap, soil (minerals?), roots, cereals, insects (incidental?), bird chicks and eggs.
Reproduction: Females polyoestrus with bimodal peaks: winter (Dec.-Mar.) mating produces young in spring (Mar.-May); spring mating yields young during summer (July-Sept.). Gestation 36 to 42 days (depending on weather and food). Ave. litter is 3 young (kittens). Young outside at 7 wks; fully weaned by 10 wks and independent at 12 to 16 wks. Sexually mature at 6 months old. Breeding heavily influenced by mast crop and may skip breeding seasons following poor autumn.
Behaviour & Sociality: Primarily solitary; drey sharing known, individuals seem familiar with each other. Hierarchy system known between and within sexes; males not necessarily dominant to females. Peak dispersal in autumn (some in summer and spring). Spend less time on ground than Greys. Emit various acoustically distinct calls; foot stomping, tail flicking and chasing my accompany agonistic calls. During breeding season, single female may be pursued by several males. Chasing, chattering and tail-flicking often witnessed during mating chases. Kittens engage in solitary object-play and social play, including chasing; occasionally solitary play persists in adults, although apparently less common than in Greys, and includes erratic rolling and jumping.
Threats: Large numbers killed on roads and by viruses (such as squirrelpox). Habitat loss, encroachment by Greys and changes to habitat management also implicated in species decline. Historically persecuted as pest to forestry. Globally, predators include foxes, wildcats, martens, goshawks, raptors (esp. buzzards), stoats, coyotes, snakes and bobcats.
Atlas of the Mammals of Great Britain & Northern Ireland - by Multiple Contributors
Pelagic Publishing -- 2020 -- ISBN: 978-1784272043
Belinda, The Forest How Red Squirrel - by Peter Trimming
The Book Guild -- 2016 -- ISBN: 978-1910878552
Britain’s Mammals 2018: The Mammal Society’s Guide to their Population & Conservation Status - by Multiple Contributors
The Mammal Society -- 2020 -- ISBN: 978-0993567339
Collins Field Guide: Mammals of Britain and Europe - by David MacDonald and Priscilla Barrett
HarperCollins Publishers -- 1993 -- ISBN: 978-0002197793
Highland Deer Forest - by Lea MacNally
J.M. Dent & Sons Ltd. -- 1970 -- ISBN: 978-0330234665
Mammals of the British Isles: Handbook, 4th Edition - by Stephen Harris and Derek Yalden (eds)
The Mammal Society -- 2008 -- ISBN: 978-0906282656
The natural history "bible" covering all British mammals with detailed coverage of their biology, behaviour, ecology and taxonomy written by experts in the field and referenced to the primary literature.
Mind the Gap: Postglacial colonization of Ireland - by John L. Davenport, David P. Sleeman & Peter C. Woodman (eds)
Irish Naturalists' Journal -- 2008
Nick Baker’s British Wildlife: A month by month guide - by Nick Baker
New Holland Publishers -- 2003 -- ISBN: 978-1845171131
Red Squirrels - by Helen Butler
Wight Squirrel Project -- 1998 -- ISBN: 978-0955231438
Red Squirrels: Ecology, Conservation & Management in Europe - by Craig Shuttleworth, Peter Lurz & Matthew Hayward
European Squirrel Initiative -- 2015 -- ISBN: 978-0954757618
Silent Fields: The long decline of a nation’s wildlife - by Roger Lovegrove
Oxford Univesrity Press -- 2007 -- ISBN: 978-0199548156
Simon King’s Wildguide - by Simon King
BBC Books -- 1994 -- ISBN: 978-0563364962
Squirrels - by Monica Shorten
Collins -- 1954 -- ISBN: 978-1616905774
Squirrels - by Jessica Holm
Whittet Books -- 1987 -- ISBN: 978-1873580172
Squirrels in Britain - by Keith Laidler
David & Charles -- 1980 -- ISBN: 978-0715378250
Squirrels in Your Garden - by Doreen King
Kingdom Books -- 1998 -- ISBN: 978-1852790288
The British Mammal Guide - by Steve Evans & Paul Wetton
Isabelline Films -- 2015 -- ISBN: N/A
The Conservation of Red Squirrels - by John Gurnell & Peter Lurz (eds)
PTES -- 1997 -- ISBN: 978-1855800144
The Encyclopaedia of Mammals - by David MacDonald (ed.)
Brown Reference Group -- 2006 -- ISBN: 978-0199206087
The Eurasian Red Squirrel - by Stefan Bosch & Peter Lurz
Westarp Wissenschaften -- 2012 -- ISBN: 978-3894322588
The Natural History of Squirrels - by John Gurnell
Christopher Helm Publishers -- 1987 -- ISBN: 978-0747012108
The New Amateur Naturalist - by Nick Baker
HarperCollins Publishers -- 2004 -- ISBN: 978-0007157310
The Red Squirrel - by Jessica Holm
Shire Natural History -- 1989 -- ISBN: 978-0747800224
The Red Squirrel: Redressing the Wrong - by Charles Dutton
European Squirrel Initiative -- 2004 -- ISBN: N/A
The Wildlife Trust’s Handbook of Garden Wildlife - by Nicholas Hammond
Bloombury -- 2014 -- ISBN: 978-1472915863
UK Mammals: Species Status & Population Trends - by The Tracking Mammals Partnership
JNCC/TMP -- 2005 -- ISBN: 978-1861075680
Urban Mammals: A Concise Guide - by David Wembridge
Whittet Books -- 2012 -- ISBN: 978-1873580851
Urban Wildlife - by Peter Shirley
Whittet Books -- 1996 -- ISBN: 978-1873580233
Wild Animals of Britain & Europe - by Helga Hofmann
HarperCollins Publishers -- 1995 -- ISBN: 978-0007627271