Geographic Range
Caucasian squirrels are native to Greece, Turkey, Armenia, Georgia, Azerbaijan, Iran,
Iraq, Palestine, Jordan, Lebanon and Syria. The southernmost recorded range of their
distribution is the forest covered mountains of Jarash and Ajlum in Jordan (Amr et
al. 2006).
- Biogeographic Regions
- palearctic
Habitat
Caucasian squirrels inhabit coniferous and temperate mixed forests. Their nest are
usually found in the tree hollows, and they seem to prefer pine trees (such as oak,
walnut, and willow) to deciduous trees. Their nests are also found under rocks, inside
heaps of stones, and in residential areas, such as graveyards and abandoned cattle
sheds (Amr et al. 2006).
- Habitat Regions
- temperate
- terrestrial
- Terrestrial Biomes
- forest
- Other Habitat Features
- suburban
- agricultural
Physical Description
Caucasian squirrels have a dental formula of incisors 1/1, canines 0/0, premolars
1/1, and molars 3/3, totaling 20. They have four fingered fore feet and five fingered
hind feet. Sex differences in body length or mass are not evident (Amr et al., 2006;
Hayssen, 2008).
Their ventral fur usually has a reddish color and fur color changes in winter. Adult
dorsal fur color in winter ranges from pale-blackish-grey to pale-reddish-buff. The
dorsal fur color in summer varies from very light-reddish-grey to pale-blackish-grey.
The ventral fur color in winter ranges from light-yellowish-buff to light-reddish-buff.
The ventral color in summer varies from reddish-yellow to rich orange. Some individuals
have ear tufts in winter, but these disappear in summer through autumn. (Albayrak
and Arslan, 2006; Amr et al., 2006; Hayssen, 2008; Pamukoglu and Albayrak, 1996; Wauters
and Dhondt, 1992)
- Other Physical Features
- endothermic
- heterothermic
- bilateral symmetry
- Sexual Dimorphism
- sexes alike
Reproduction
The mating system of Caucasian squirrels is currently unknown. However, a closely
related species,
Eurasian red squirrels
, are well-studied. Eurasian red squirrel females in estrus give off a scent that
males can detect during mating season. Males follow her for one or more hours, but
males give up pursuit when she leaves their home range. Male’s home range size depends
on their rank in dominance hierarchy, with dominant males holding larger ranges resulting
in more chances to mate (Lurz, Gurnell, and Magris, 2005).
- Mating System
- polygynous
- polygynandrous (promiscuous)
There is no information available regarding general reproductive behavior of Caucasian
squirrels, but their close relative,
Eurasian red squirrels
are well studied. Both males and females are sexually mature at 9 to 19 months old.
Breeding season of
Eurasian red squirrels
is prolonged from December to January and August to September. Females are polyestrus
and in season for only one day per breeding cycle. Mating peaks occur in winter and
spring. The average gestation period in temperate tree squirrels ranges from 39 to
44 days, so it is assumed that gestation periods for Caucasian squirrels may fall
within that range. Their close relative
Eurasian red squirrels
usually have two to five offspring per litter. Offspring have been weaned at eight
to ten weeks (Lurz et al., 2005; Emmons, 1979; Mari et al., 2008).
- Key Reproductive Features
- iteroparous
- seasonal breeding
- gonochoric/gonochoristic/dioecious (sexes separate)
- sexual
No information on the parental investment of Caucasian squireels was found. However,
Eurasian red squirrels
males do not provide parental care. Females nurse and protect offspring in their
nests. Maternal care may extend after the young are weaned (Lurz, Gurnell, and Magris,
2005).
- Parental Investment
- altricial
- female parental care
-
pre-weaning/fledging
-
provisioning
- female
-
protecting
- female
-
provisioning
-
pre-independence
-
provisioning
- female
-
protecting
- female
-
provisioning
Lifespan/Longevity
There is no information available regarding average lifespan of Caucasian squirrels.
Eurasian red squirrels
live up to seven years in the wild and ten years in captivity. Since Caucasian squirrels
inhabit some arid areas, water scarcity during the summer season can lower survival
rates (Amr et al., 2006; Frentinos, 1972; Lurz, Gurnell, and Magris, 2005).
Behavior
There is little information on the behavior of Caucasian squirrels. They are diurnal
and stay active all year except in winter. They are most active in summer season.
Caucasian squirrels become most active during the early morning to morning and during
the two hours before sunset in early summer. Like other tree squirrels, they are territorial.
The animal marks territories with urine and feces. The marks are renewed several times
every day. Diurnal tree squirrels tend to be solitary during non-mating seasons, so
Caucasian squirrels may be a solitary, as well (Abi-Said and Amr 2012, Amr et al.
2006, Farentinos 1972).
Home Range
There is no information available regarding home range of Caucasian squirrels. However,
Eurasian red squirrel
males tend to have larger home range than females. Higher-ranking individuals have
larger home ranges (Lurz, Gurnell, and Magris, 2005).
Communication and Perception
No detailed information is available regarding communication of Caucasian squirrels.
They do call, so they may communicate with sounds (e.g. warning calls) like other
tree squirrels. During breeding seasons, the closely related species,
Eurasian red squirrels
, communicate with body posture and sounds including chucking calls and teeth chattering.
Eurasian red squirrel females in estrus also give off a scent that males can detect
during mating season (Amr et al., 2006; Lurz, Gurnell, and Magris, 2005).
Food Habits
Caucasian squirrels are herbivorous. They mostly eat pine acorns, other seeds and
fruits. They sometimes forage in residential areas, and some are observed scavenging
food from garbage dumpsters. Their close relative
Eurasian red squirrels
, have similar diets to Caucasian squirrels, but it also eats berries and fungi. When
food abundance is low, the diet of Eurasian red squirrels become varied, including
birds’ eggs, tree bark, flowers, and invertebrates (Amr et al., 2006; Sadeghinezhad
et al., 2012).
- Plant Foods
- seeds, grains, and nuts
- fruit
Predation
Little is known of predators of Caucasian squirrls. One study reports predation by
large birds such as
golden eagles
or
eagle owls
. Many tree squirrels are eaten by many predators;
Eurasian red squirrel
are consumed by
pine martens
,
wild cats
, some owls, and raptors (De Cupere et al., 2009; Lurz, Gurnell, and Magris, 2005).
Ecosystem Roles
There little information regarding ecosystem roles of Caucasian squirrels. However,
they eat seeds and fruits and therefore, likely have an important influence on the
forest ecosystem as seed dispersers. Additionally, food remains are found in several
ground burrows further supporting this hypothesis (Miyaki, 1987).
- Ecosystem Impact
- disperses seeds
Economic Importance for Humans: Positive
Not much information of positive economic importance for humans is found, but some
studies mention that people keep Caucasian squirrels, as a companion pet (Khazraiinia
et al., 2008; Tootian et al., 2012; Masseti, 2010).
- Positive Impacts
- pet trade
Economic Importance for Humans: Negative
Little is known about the negative economic effects of Caucasian squirrels on humans.
However, one study reports that they forage at residential gardens so they may have
negative impacts on gardens (Albayrak and Arslan, 2006).
Conservation Status
Caucasian squirrels are considered to be in the least concern conservation status.
However, population decline is reported in some areas of their distribution, such
as in Turkey mainly due to fragmentation and loss of habitat. Illegal hunting also
harms Caucasian squirrl populations (Amr et al., 2006; Yigit et al., 2012).
Additional Links
Contributors
Eri Nakanishi (author), University of Alaska Fairbanks, Laura Prugh (editor), University of Washington, Laura Podzikowski (editor), Special Projects.
- Palearctic
-
living in the northern part of the Old World. In otherwords, Europe and Asia and northern Africa.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- temperate
-
that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).
- terrestrial
-
Living on the ground.
- forest
-
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
- suburban
-
living in residential areas on the outskirts of large cities or towns.
- agricultural
-
living in landscapes dominated by human agriculture.
- endothermic
-
animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.
- heterothermic
-
having a body temperature that fluctuates with that of the immediate environment; having no mechanism or a poorly developed mechanism for regulating internal body temperature.
- bilateral symmetry
-
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
- polygynous
-
having more than one female as a mate at one time
- polygynandrous
-
the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.
- iteroparous
-
offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).
- seasonal breeding
-
breeding is confined to a particular season
- sexual
-
reproduction that includes combining the genetic contribution of two individuals, a male and a female
- altricial
-
young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.
- female parental care
-
parental care is carried out by females
- arboreal
-
Referring to an animal that lives in trees; tree-climbing.
- diurnal
-
- active during the day, 2. lasting for one day.
- motile
-
having the capacity to move from one place to another.
- solitary
-
lives alone
- acoustic
-
uses sound to communicate
- chemical
-
uses smells or other chemicals to communicate
- visual
-
uses sight to communicate
- tactile
-
uses touch to communicate
- acoustic
-
uses sound to communicate
- chemical
-
uses smells or other chemicals to communicate
- pet trade
-
the business of buying and selling animals for people to keep in their homes as pets.
- herbivore
-
An animal that eats mainly plants or parts of plants.
- frugivore
-
an animal that mainly eats fruit
- granivore
-
an animal that mainly eats seeds
References
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Albayrak, I., A. Arslan. 2006. Contribution to the Taxonomical and Biological Characteristics of Scirus anomalus in Turkey (Mammalia: Rodentia). Turkish Journal of Zoology , 30: 111-116.
Amr, Z., E. Edi, M. Qarqaz, M. Baker. 2006. The Status and Distribution of the Persian Squirrel, Sciurus anomalus (Mammalia: Rodentia: Sciuridae) in Dibbeen Nature Reserve, Jordan. Zoologische Abhandlungen , 55: 199-207.
De Cupere, B., S. Thys, W. Van Neer,, A. Ercynck, M. Corremans, M. Waelkens. 2009. Eagle Owl (Bubo bubo) pellets from Roman Sagalassos (SW Turkey): distinguishing the prey remains from nest and roost sites. International Journal of Osteoarchaeology , 19: 1-22.
Emmons, L. 1979. Observations on Litter Size and Development of Some African Rainforest Squirrels.. Biotropica , 11(3): 207-213.
Farentinos, R. 1972. Social dominance and mating activity in the tassel-eared squirrel (Sciurus aberti ferreus). Animal Behavior , 20: 316-326.
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Khazraiinia, P., A. Rostami, H. Haddadzadeh, S. Nassiri. 2008. Hematological Characteristics and Hemoglobin Typing of the Persian Squirrel (Sciurus anomalus). Journal of Exotic Pet Medicine , 17(1): 44-48.
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Mari, V., S. Martini, C. Romeo, A. Molinari, A. Martinoli, G. Tosi, L. Wauters. 2008. Record litter size in the Eurasian red squirrel (Sciurus vulgaris). Hystrix, the Italian Journal of Mammalogy (n.s.) , 19(1): 61-65.
Masseti, M. 2010. Homeless mammals from the Ionian and Aegean island. Bonn zoological Bulletin , 57(2): 367-373.
Miyaki, M. 1987. Seed dispersal of the Korean pine, Pinus koraiensis, by the Red squirrel, Sciurus vulgaris. Ecologial Research , 2: 147-157.
Pamukogul, N., I. Albayrak. 1996. The rodents of kastamonu province (Mammalia: Rodentia). Communications de la Faculté des Sciences de l'Université d'Ankara. Séries C , 14: 1-22.
Sadeghnezhad, J., Z. Tootian, G. Akbari, R. Chiocchetti. 2012. The Topography and Gross Anatomy of the Abdominal Gastrointestinal Tract of the Persian Squirrel (Sciurus anomalus). International Journal of Morphology , 30/2: 524-530.
Tootian, Z., J. Sadeghinezhad, M. Taghi Sheibani, S. Fazelipour, N. De Sordi, R. Chiocchetti. 2012. Histological and mucin histochemical study of the small intestine of the Persian squirrel (Sciurus anomalus). Anatomical Science International , N/A: 1-8.
Wauters, L., A. Dhondt. 1992. Spacing behavior of red squirrel, Sciurus vulgaris: variation between habitats and the sexes. Animal Behavior , 43: 297-311.
Yigit, N., B. Kryštufek, M. Sozen, A. Bukhnikashvili, G. Shenbrot. 2012. "Sciurus anomalus" (On-line). IUCN Red List of Threatened Species. Accessed November 15, 2012 at http://www.iucnredlist.org/details/20000/0 .