46 Sciurus carolinensisMéxico, and various localities in western Canada, Hawaii,
and the western continental USA. Introductions to Austra-
lia, Hawaii, and perhaps México have failed.
geographic variation: Five subspecies are recognized.
S. c. carolinensis—most of the southern portion of the
range, except for the Appalachian Mountains (USA).
This moderately sized form has the coloration de-
scribed above.
S. c. extimus—lower half of Florida (USA). This subspecies is
the smallest and darkest.
S. c. fuliginosus—southern half of Louisiana, and extreme
southern Mississippi and Alabama (USA). This form has
rich dark colors, with the venter often a shade of
cinnamon.
S. c. hypophaeus—northwestern portion of the range, includ-
ing most of Minnesota, Wisconsin, and the Upper Penin-
sula of Michigan (USA). This form is the largest of the
subspecies; and it often has a reduced area of white on
the venter, with an increased encroachment of the dorsal
coloration.
S. c. pennsylvanicus—northeastern portion of the range, the
Appalachian Mountains, and extending from Iowa
across the southern and eastern Great Lakes states (USA).
This is another large subspecies, but it lacks the en-
croachment of dorsal coloration to the venter.
conservation: IUCN status—least concern. Population
trend—stable.
habitat: Eastern gray squirrels are found in hardwood or
mixed forests, especially with a diversity of mature to overly
mature trees that provide abundant supplies of hard mast
(acorns, walnuts, and hickory nuts) and nest cavities. It can
be found in urban and suburban areas, even when trees are
somewhat sparse.natural history: This species is diurnal. Eastern gray
squirrels move readily in the canopy or on the ground
throughout the year. Mating activity peaks twice annu-
ally: December–February and May–June. Males follow fe-
males to assess the latter’s reproductive condition by sniff -
ing genitalia, and they repeatedly visit when a female
approaches estrus. Estrus lasts less than one day during a
breeding season, and males congregate at the nest of the
female, often at fi rst light. Up to 34 males will pursue a fe-
male during her mating bout. Dominant males are able to
mate by actively pursuing the female; however, lower-
ranking males, typically younger individuals, are able to
copulate by waiting on the periphery of the bout and locat-
ing the female when she evades the ultra-aggressive domi-
nant males. Copulation lasts less than 30 seconds. A copu-
latory plug forms within the female from the coagulation
of semen. Females will remove the plugs and mate with
several males. After a 44–day gestation, a litter averaging
two to four (maximum of eight) young is born in a tree cav-
ity or leaf nest. Leaf nests are large spherical structures
constructed in the canopy, using twigs and leaves, with a
central nest chamber often lined with shredded bark and
leaves. A few females may produce two litters in a year;
however, most adult females only produce a single litterSciurus carolinenesis. Photo courtesy Brian E. Kushner, Brian
KushnerPhoto.com.Sciurus carolinenesis. Photo courtesy Caroline M. Thorington.