Living Organisms / Animalia / Craniata / Mammalia / Rodentia / Sciuridae / Sciurus / Species
Sciurus carolinensis - Eastern grey squirrel (Click photographs/illustrations: full picture & further details)
Click Photo for full-page view Click Photo for full-page view Click Photo for full-page view Click Photo for full-page view Click Photo for full-page view

INFORMATION AVAILABLE

GENERAL & REFERENCES

APPEARANCE / MORPHOLOGY

LIFE STAGES / NATURAL DIET / PHYSIOLOGY

BEHAVIOUR

HABITAT & RANGE

CONSERVATION

Return to top of page

General and References

Alternative Names (Synonyms)

  • Grey squirrel
  • American grey squirrel
  • Eastern gray squirrel (North America)
  • Cat squirrel (North America)
  • Migratory Squirrel (North America)
  • Gray Squirrel
  • Ecureuil gris (French)
  • Grauhörnchen (German)

Names for new-borns / juveniles

--
Names for males --
Names for females --

Return to top of page

General Appearance

Typical squirrel with slender body and long bushy tail. Mainly grey with some brown on back and grizzled grey tail B142, D30

Similar Species

  • Differentiated from Sciurus vulgaris - Eurasian red squirrel: larger and sturdier, with slightly longer skull, no ear tufts, mainly grey colouration (B142, B144, B148)
  • Differentiated from Myoxus glis - Fat dormouse: much larger size B142
Sexual Dimorphism Minimal. Heavily pigmented scrotum in sexually active male, pigmented nipples in adult female B142 (B142)

Return to top of page

References

Species Author

Debra Bourne

Major References

Husbandry references:
B151, D24

ORGANISATIONS
(UK Contacts)

ELECTRONIC LIBRARY
(Further Reading)
Click image for full contents list of ELECTRONIC LIBRARY

  • --

Return to top of page

TAXA Group (where information has been collated for an entire group on a modular basis)

Parent Group

  • Squirrels (Rodents)

Specific Needs Group referenced in Management Techniques

  • Squirrels (Rodents)

Return to top of page

Husbandry Information

Notes

--
Individual Techniques linked in Wildpro

Return to top of page

Appearance / Morphology

Measurement & Weight

Length Head-body length: about 10-12ins./25-30cm (B144); about 26 cm (B148); 240-285mm (D30); 240-285 cm mean 260cm (B142).
Height --
Adult weight General 14-25oz./400-710g (B144) Weight higher early winter, lowest late spring to summer (B142).
Male 440-650g mean 532g (B142).
Female 400-720g mean 568g (B142).
New-born weight 0.4-0.6oz. / 13-17g (B144); 14-18g (B142).
Growth rate --

Return to top of page

Head

General --

Skull: Slightly longer than that of Sciurus vulgaris - Eurasian red squirrel and shallower (B142, B148).

Nose:

Ears: no conspicuous ear tufts (B142, D30).

Dentition (Teeth)
  • I 1/1 C 0/0 P 1-2/1, M 3/3 (B142, B147).
  • Cheek teeth rooted, low-crowned, quadrate, cuspidate. (B142, B147).
  • Deciduous lower and second upper premolars shed at 16 weeks of age; others not deciduous (B142).
Eyes Large (B147)

Return to top of page

Legs and Tracks

Hindfoot length: mean more than 60mm (B142)

Return to top of page

Tail

Long, bushy, multi-coloured as hairs banded brown black and yellow (B147, D30)

Length: 8-9.4in./20-23.5cm (B144); about 21cm (B148); 19.5-24.0cm mean 22.0cm (B142).

Return to top of page

Coat / Pelage

Adult Female Summer: 
  • Dorsal: overall grey, with mid-dorsal area more brown.
  • Flanks and limbs: more chestnut/russet
  • Ventral: white
  • Tail: hairs banded black and brown, indistinctly white fringed 
  • Ears: grey

Winter: thicker coat

  • Dorsal grey with midline and head more yellow-brown.
  • Tail dark grey with white fringe
  • Ears: back surface white, short tufts. 

(B142, B148, D30)

Variations (If present)
  • Dark grey and black (melanistic) individuals common in northern part of North American range 
  • Melanistic forms rare in Britain
  • Albinos rare. seen in urban areas in North America, also in England (Kent, Surrey, Sussex)
  • Erythistic (reddish) forms seen occasionally in south-east England.

(B142, B143)

Moult
  • Body moult twice yearly.
  • Spring moult: from front to back
  • Autumn moult: from back to front.
  • Ear tufts moult once yearly, with new hairs growing in late summer/autumn, through to December
  • Tail moult once yearly, with new hairs growing in late summer/autumn.

(B142)

New-born / Juvenile Juvenile: Darker grey than adult, and with more brown in coat (B142)

Return to top of page

Neonate (New-born) Characteristics

Blind, deaf, naked (B142, B147).

Return to top of page

Detailed Anatomy Notes
(Summary information provided for pertinent species-specific data cross-referenced in Wildpro)

Reproductive: Four pairs of nipples. Darkly pigmented from first pregnancy onwards (B142).

Return to top of page

Life Stages / Natural Diet / Physiology

Reproductive Stages

Breeding Season
  • Affected by food supply and weather B142
Oestrus / Ovulation --
Gestation / Pregnancy
Parturition / Birth
  • February to July (B142)
Neonatal development
  • Birth: blind, deaf and naked.
  • 14 days: skin on back pigmented, hairs appearing. 
  • 20 days: body covered with hair.
  • 19-21 days: lower incisors erupted
  • 31-42 days: upper incisors erupted
  • 28-35: days ears open
  • 28-30 days eyes open (about 90g).
  • 7 weeks: start leaving nest, eating solid food. 
  • 8-10 weeks: weaned
  • 3-4 months: moult to adult coat.

(B142, B147)

Litter size
  • 1-9, average 3 (B147)1-4, usually 2-3 (B144); average 3, usually 2-4, range 1-7 B142
Time between Litters / Litters per year
  • 1-2 litters (B142)
Lactation / Milk Production
Sexual Maturity
  • Within one year (B147) mainly end of first year (B144), 10-12 months, rarely younger (B142).
Longevity
  • Over 12 years old (pregnant female) recorded in wild and 23 years in captivity (B144, B147)

Return to top of page

Natural Diet

  • Seeds, plant material.
  • May eat 60-80g seeds per day (laboratory studies)

(B142)

Return to top of page

Detailed Physiology Notes
(Summary information provided for pertinent species-specific data cross-referenced in Wildpro)

Temperature --
Pulse --
Respiration --
Faeces --
Haematology / Biochemistry --
Chromosomes 2n = 40, FNa =76 (North America) (B142)
Other --

Return to top of page

Behaviour

Feeding Behaviour

Sometimes forage on ground

Bury food (nuts, acorns) in multiple small caches

(B142, B147, B148)

Return to top of page

Parental Behaviour

--

Return to top of page

Social Behaviour / Territoriality

Intra-specific
  • Density may be 5-50 per hectare
  • Home range may be only 0.5 hectare.
  • Male home range generally larger than that of female
  • Home range size affected by food supply, habitat type, population density.
  • Smaller inter-individual distances than for Sciurus vulgaris - Eurasian red Squirrel.
  • Foraging area may move in autumn due to differences in food availability 
  • Hierarchy within and between sexes
  • Fights rare, but include wrestling and chasing with biting
  • Peak aggression during breeding and dispersal
  • Groups of adults may huddle in nests, particularly in winter

(B142, B147)

Inter-specific --

Return to top of page

Sexual Behaviour

  • Promiscuous.
  • Little courtship.
  • Males may congregate on home range of oestrous female, and fight.
  • Mating chases of several males after one female may occur; dominant male presumed to mate with female.
  • Pair separate after mating.

(B142, B147),

Return to top of page

Predation in Wild

  • Pine marten, wild cat, owls, raptor (e.g. goshawk).
  • Foxes, cats, dogs while on ground.
  • Stoats may take nestlings.

(B142)

Return to top of page

Activity Patterns

  • Arboreal, but less so than Sciurus vulgaris - Eurasian red squirrel
  • Agile at traveling along branches
  • Come to ground to forage, and to bury food
  • Do not hibernate
  • In stormy/very cold weather may remain in nest until need to leave to find food

(B142, B144, B147, B148)

Circadian
  • Diurnal, with activity peaks early morning and late afternoon, but midday in colder areas in winter.
  • May feed on moonlit nights in summer and autumn

B147

Return to top of page

Habitat and Range

General Habitat Type

  • Forests, parks (B144)
  • Broad-leaved woodland, mainly with many tree species and particularly mature oak-hickory forests (North America).
  • Britain: Wide range of habitats, particularly mature broad-leaved forests (oak, beech, sweet chestnut, hazel), but also mixed woodland (broad-leaved/coniferous), mature coniferous, hedgerows, parks, gardens and urban areas with mature trees.

(B51, B142, D30)

Return to top of page

Nests / Burrows / Shelters

  • In tree hollow (ground level to about 12 metres) or ball/dome shaped nest of leaves and twigs built in branches.
  • More than one nest 
  • Domed structure, side entrance. lines with grass and leaves 
  • Leafy platform on branches in summer

(B142, B147, B148)

Return to top of page

Distribution and Movement (Migration etc.)

Normal South-eastern Nearctic: eastern and central USA, south-eastern Canada (B51, B143, B147)
Occasional and Accidental --
Introduced
  • Europe: Great Britain, Ireland, Northern Italy

  • South Africa

(B51, B142, B143, B147)

Return to top of page

Conservation

Intraspecific variation

  • Five subspecies recognised in North America.
  • Size cline in North America: body mass increases further north.
  • Black squirrels in north-eastern part of North American range.

(B143)

Return to top of page

Conservation Status

Wild Population -
(Importance)
  • No international conservation status (B143)

  • Important game animal in North America (B143)

  • Forestry pest in Britain and Italy (B143).

  • In Britain: introduced 19th century and early 20th century; common, increasing population and range. Pre-breeding population estimate of about 2,520,000, with 2,000,000 in England, 200,000 in Scotland, 320,000 in Wales. Population estimate of this widely-distributed species was based on a limited amount of data and considered likely to be inaccurate by up to 50% in either direction (B221).

General Legislation
CITES listing --
Red-data book listing --
Threats --
Captive Populations --
Trade --

Return to top of page