Sciurus vulgaris 75S. v. lilaeus—western Balkan peninsula. It is a generally
brownish form.
S. v. mantchuricus—“Manchuria” (northeastern China) and
the Korean Peninsula. This subspecies has a black tail
year-round, and a dark gray winter pelage.
S. v. martensi—western Siberia, to west of the Ob River (Rus-
sia). This form has a chestnut tail, with a pale gray winter
pelage and yellow buff on the hips in the summer
pelage.
S. v. ognevi—western Russia. This smallish form is highly
variable in coloration, but the winter pelage often is light
grayish with a tinge of buff.
S. v. orientis—island of Hokkaido (Japan). This endemic form
is gray, with a white venter.
S. v. rupestris—Sakhalin Island (far eastern Siberia). This has
a black or black chestnut dorsum, with a black tail through-
out the year.
S. v. ukrainicus—Ukraine. This form has a dorsum and tail
that retain much of their reddish brown color in the win-
ter pelage.
S. v. varius—northern Scandinavia. This form has a light
bluish gray winter dorsum, with a dark chestnut to red
tail.
conservation: IUCN status—least concern. Population
trend—decreasing. The subspecies S. v. leucurus (in the Brit-
ish Isles) is considered to be in critical decline. S. vulgaris is
considered near threatened in Mongolia and Croatia and
vulnerable in Poland.
habitat: Eurasian red squirrels are most abundant in large
tracts of coniferous forest, but they also occur in deciduous
and mixed forests and parklands, and range from lowlands
to subalpine forests within the Alps. They can be found in
urban and suburban environs, conifer plantations, and sec-
ondary forests.
natural history: This species is diurnal. Eurasian red
squirrels forage in the canopy and on the ground through-
out the year. Mating activity begins as early as December
and can continue until August. Males track the females’ re-
productive condition by following and sniffi ng their genita-
lia. Estrus lasts less than one day during a breeding season.
Males congregate, and more than 10 males can pursue a fe-
male during her mating bout. Dominant males are able to
obtain the majority of matings, which occur along tree
trunks, in branches, on the ground, or in dens. Copulation
lasts less than 30 seconds. A copulatory plug forms within
the female from the coagulation of semen. Females will re-
move the plugs and mate with multiple males. A litter aver-
aging one to six young is born in a tree cavity or leaf nest.
Leaf nests are large spherical structures constructed in the
canopy using twigs and leaves. They have a central nest
chamber, which is often lined with shredded bark, mosses,
and leaves. Peak seasons of birth are February–April and
May–August. Both body condition and dominance rank
positively infl uence the reproductive success of males and
females. A few females produce two litters in a year; adult
females typically produce a single litter each year. The
young emerge after 6–7 weeks and weaning is completed
between 8 and 12 weeks. Adult size is reached at about 1
year. Most individuals do not reproduce until at least 10–11
months of age, and many will not do so until they are 2
years old. The lifetime reproductive success for adult fe-
males averages about fi ve young per lifetime (range = 1–11).
Natal dispersal occurs soon after weaning, and all males
and females leave their natal area. Eurasian red squirrels are
relatively solitary; however, several adults will share a nest
at night, especially in cold months during the winter and
spring. They will scent-mark trees with their cheek glands,
often at traditional sites; they also seem to use urine for
scent-marking.
Eurasian red squirrels feed heavily on tree seeds, espe-
cially those of conifers, but they also eat fruits, buds, fl ow-
ers, shoots, herbs, fungi, bark, and lichens. Occasionally
animal matter (including insects, bird eggs, and nestlings) is
consumed. A conspicuous behavior is the annual scatter-
hoarding of hard low-perishability acorns, other nuts, and
cones each fall to serve as the winter food store. Hoarding
activities are more common in deciduous forests, in com-
parison with coniferous forests. Squirrels collect tree seeds
near the parent tree, disperse to considerable distances, and
bury them just under the surface. These behaviors serve to
decrease loss of this critical food source to seed predators.
Caches are recovered using a combination of spatial mem-
ory and olfactory cues; however, the spatial memory of S.
vulgaris seems to be less acute than that of introduced east-
ern gray squirrels (S. carolinensis). Fungi are also cached in
the branches of trees. Success in the recovery of caches in-
creases the probability of survival and augments repro-
ductive success. Home range overlap is modest, especially
among females that defend core areas, such as during lacta-
tion. Home ranges vary from 2.4 to 19.7 ha in females and 6.2
to 31.4 ha in ma les, a nd ca n be up to 47.0 ha in high-elevation
forests. Survivorship and reproduction are positively cor-
related with the seed crop of trees. The fi rst-year survival
rate is low, often less than 25 percent. Annual adult survi-
vorship is high, at greater than 50 percent throughout adult
life; longevity in the fi eld is greater than 7.0 years and, in
captivity, greater than 10.0 years.
Predators of Eurasian red squirrels include mustelids,
felids, canids, and raptors. Predation accounts for 16–61 per-