Sciuridae (Family)

Overview

Squirrels belong to a large family of small or medium-sized rodents called the Sciuridae. The family includes tree squirrels, ground squirrels, chipmunks, marmots (including woodchucks), flying squirrels, and prairie dogs. Squirrels are indigenous to the Americas, Eurasia, and Africa, and have been introduced to Australia. The earliest known squirrels date from the Eocene and are most closely related to the mountain beaver and to the dormouse among living species.

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The word "squirrel", first specified in 1327, comes from Anglo-Norman esquirel from the Old French escurel, the reflex of a Latin word sciurus. This Latin word was borrowed from the Ancient Greek word s???????, skiouros, which means shadow-tailed, referring to the bushy appendage possessed by many of its members.^[1]^{<
a
href="#cite_note-1">[2]}

The native Old English word, acweorna, survived only into Middle English (as aquerne) before being replaced.^[3] The Old English word is of Common Germanic origin, with cognates such as German Eichhorn, Norwegian ekorn, Dutch eekhoorn, Swedish ekorre and Danish egern.

Characteristics

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Skull of an Oriental giant squirrel (genus Ratufa) - note the classic sciuromorphous shape of the anterior zygomatic region.

Squirrels are generally small animals, ranging in size from the Afric an pygmy squirrel at 7?10 cm (2.8?3.9 in) in length and just 10 g (0.35 oz) in weight, to the Alpine marmot which is 53?73 cm (21?29 in) long and weighs from 5 to 8 kg (11 to 18 lb). Squirrels typically have slender bodies with bushy tails and large eyes. Their fur is generally soft and silky, although much thicker in some species than others. The color of squirrels is highly variable between?and often even within?species.^[4]

The hind limbs are generally longer than the fore limbs, and they have four or five toes on each foot. Their paws on their fore feet include a thumb, although this is often poorly developed. The feet also have soft pads on the undersides.^[5]

Squirrels live in almost every habitat from tropical rainforest to semiarid desert, avoiding only the high polar regions and the driest of deserts. They are predominantly herbivorous, subsisting on seeds and nuts, but many will eat insects and even small vertebrates.^[6]

As their large eyes indicate, squirrels generally have an excellent sense of vision, which is especially important for tree-dwelling species. They also have very versatile and sturdy claws for grasping and climbing.^[7] Many also have a good sense of touch, with vibrissae on their heads and limbs.^[5]

The teeth of sciurids follow the typical rodent pattern, with large gnawing incisors that grow throughout life, and grinding cheek teeth set back behind a wide gap, or diastema. The typical dental formula for sciurids is $Upper: 1.0.1.3, lower: 1.0.1.3$ ^[]

Behavior

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Several species of squirrels have melanistic phases. In large parts of United States and Canada, the most common variety seen in urban areas is the melanistic form of the eastern gray squirrel.
Squirrels breed once or twice a year and give birth to a varying number of young after three to six weeks, depending on species. The young are born naked, toothless, and blind. In most species of squirrel, only the female looks after the young, which are weaned at around six to ten weeks of age and become sexually mature at the end of their first year. Ground-dwelling species are generally social animals, often living in well-developed colonies, but the tree-dwelling species are more solitary.^[5]
Ground and tree squirrels are typically diurnal or crepuscular,^[8] while flying squirrels tend to be nocturnal?except for lactating flying squirrels and their offspring, which have a period of diurnality during the summer.^[9]
Feeding
Squirrel eating a peanut
The Indian palm squirrel is the most common type of squirrel found in India.
Squirrels cannot digest cellulose, so must rely on foods rich in protein, carbohydrates, and fats. In temperate regions, early spring is the hardest time of year for squirrels, because buried nuts begin to sprout and are no longer available for the squirrel to eat, and new food sources have not become available yet. During these times, squirrels rely heavily on the buds of trees. Squirrels' diets consist primarily of a wide variety of plants, including nuts, seeds, conifer cones, fruits, fungi and green vegetation. However, some squirrels also consume meat, especially when faced with hunger.^[6] Squirrels have been known to eat insects, eggs, small birds, young snakes and smaller rodents. Indeed, some tropical species have shifted almost entirely to a diet of insects.^[10]
Predatory behavior has been noted by various species of ground squirrels, particularly the thirteen-lined ground squirrel.^[11] For example, Bailey, a scientist in the 1920s, observed a thirteen-lined ground squirrel preying upon a young chicken.^[12] Wistrand reported seeing this same species eating a freshly killed snake.^[13] Whitaker examined the stomachs of 139 thirteen-lined ground squirrels and found bird flesh in four of the specimens and the remains of a short-tailed shrew in one;^[14] Bradley, examining white-tailed antelope squirrels' stomachs, found at least 10% of his 609 specimens' stomachs contained some type of vertebrate, mostly lizards and rodents.^[15] Morgart observed a white-tailed antelope squirrel capturing and eating a silky pocket mouse.^[16]
Taxonomy

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Grizzled giant squirrel (Ratufa macroura) of the Ratufinae
Southern flying squirrel (Glaucomys volans) of the Pteromyini
Prevost's squirrel (Callosciurus prevosti) of the Callosciurini
Unstriped ground squirrel (Xerus rutilus) of the Xerini
Alpine marmot (Marmota marmota) of the Marmotini
The living squirrels are divided into five subfamilies, with about 58 genera and some 285 species.^[17] The oldest squirrel fossil, Hesperopetes, dates back to the Chadronian (late Eocene, about 40?35 million years ago) and is similar to modern flying squirrels.^[18]
A variety of squirrels, from the latest Eocene to the Miocene, could not be assigned with certainty to any living lineage. At least some of these probably were variants of the oldest basal "protosquirrels" (in the sense that they lacked the full range of living squirrels' autapomorphies). The distribution and diversity of such ancient and ancestral forms suggest the squirrels as a group may have originated in North America.^[19]
Apart from these sometimes little-known fossil forms, the phylogeny of the living squirrels is fairly straightforward. The three main lineages are the Ratufinae (Oriental giant squirrels), Sciurillinae and all other subfamilies. The Ratufinae contain a mere handful of living species in tropical Asia. The neotropical pygmy squirrel of tropical South America is the sole living member of the Sciurillinae. The third lineage, by far the largest, has a near-cosmopolitan distribution. This further supports the hypothesis that the common ancestor of all squirrels, living and fossil, lived in North America, as these three most ancient lineages seem to have radiated from there; if squirrels had originated in Eurasia, for example, one would expect quite ancient lineages in Africa, but African squirrels seem to be of more recent origin.^[19]
The main group of squirrels also can be split into three subgroups, which yield the remaining subfamilies. The Sciurinae contains the flying squirrels (Pteromyini) and the Sciurini, which among others contains the American tree squirrels; the former have often been considered a separate subfamily, but are now seen as a tribe of the Sciurinae. The pine squirrels (Tamiasciurus), on the other hand, are usually included with the main tree squirrel lineage, but appear to be about as distinct as the flying squirrels; hence, they are sometimes considered a distinct tribe, Tamiasciurini.^[20]
Two of the three subfamilies are of about equal size, containing between nearly 70 and 80 species each; the third is about twice as large. The Sciurinae contains arboreal (tree-living) squirrels, mainly of the Americas and to a lesser extent Eurasia. The Callosciurinae is most diverse in tropical Asia and contains squirrels which are also arboreal, but have a markedly different habitus and appear more "elegant", an effect enhanced by their often very colorful fur. The Xerinae?the largest subfamily?are made up from the mainly terrestrial (ground-living) forms and include the large marmots and the popular prairie dogs, among others, as well as the tree squirrels of Africa; they tend to be more gregarious than other squirrels, which do not usually live together in close-knit groups.^[19]
Basal and incertae sedis Sciuridae (all fossil)
Hesperopetes
Kherem
Lagrivea
Oligosciurus
Plesiosciurus
Prospermophilus
Sciurion
Similisciurus
Sinotamias
Vulcanisciurus
Subfamily Cedromurinae (fossil)
Subfamily Ratufinae ? Oriental giant squirrels (1 genus, 4 species)
Subfamily Sciurillinae ? neotropical pygmy squirrel (monotypic)
Subfamily Sciurinae
Tribe Sciurini ? tree squirrels (5 genera, about 38 species)
Tribe Pteromyini ? true flying squirrels (15 genera, about 45 species)
Subfamily Callosciurinae ? Asian ornate squirrels
Tribe Callosciurini (13 genera, nearly 60 species)
Tribe Funambulini palm squirrels (1 genus, 5 species)
Subfamily Xerinae ? terrestrial squirrels
Tribe Xerini ? spiny squirrels (3 genera, 6 species)
Tribe Protoxerini (6 genera, about 50 species)
Tribe Marmotini ? ground squirrels, marmots, chipmunks, prairie dogs, etc. (6 genera, about 90 species)
See also

[ Back to top ]
America n red squirrel
Eastern gray squirrel
Fox squirrel
Red squirrel
Squirrel relationship with humans
Tree squirrel
Western gray squirrel
s, seeds, conifer cones, fruits, fungi and green vegetation. However, some squirrels also consume meat, especially when faced with hunger.^[6] Squirrels have been known to eat insects, eggs, small birds, young snakes and smaller rodents. Indeed, some tropical species have shifted almost entirely to a diet of insects.^[10]
Predatory behavior has been noted by various species of ground squirrels, particularly the thirteen-lined ground squirrel.^[11] For example, Bailey, a scientist in the 1920s, observed a thirteen-lined ground squirrel preying upon a young chicken.^[12] Wistrand reported seeing this same species eating a freshly killed snake.^[13] Whitaker examined the stomachs of 139 thirteen-lined ground squirrels and found bird flesh in four of the specimens and the remains of a short-tailed shrew in one;^[14] Bradley, examining white-tailed antelope squirrels' stomachs, found at least 10% of his 609 specimens' stomachs contained some type of vertebrate, mostly lizards and rodents.^[15] Morgart observed a white-tailed antelope squirrel capturing and eating a silky pocket mouse.^[16]
Taxonomy

[ Back to top ]
Grizzled giant squirrel (Ratufa macroura) of the Ratufinae
Southern flying squirrel (Glaucomys volans) of the Pteromyini
Prevost's squirrel (Callosciurus prevosti) of the Callosciurini
Unstriped ground squirrel (Xerus rutilus) of the Xerini
Alpine marmot (Marmota marmota) of the Marmotini
The living squirrels are divided into five subfamilies, with about 58 genera and some 285 species.^[17] The oldest squirrel fossil, Hesperopetes, dates back to the Chadronian (late Eocene, about 40?35 million years ago) and is similar to modern flying squirrels.^[18]
A variety of squirrels, from the latest Eocene to the Miocene, could not be assigned with certainty to any living lineage. At least some of these probably were variants of the oldest basal "protosquirrels" (in the sense that they lacked the full range of living squirrels' autapomorphies). The distribution and diversity of such ancient and ancestral forms suggest the squirrels as a group may have originated in North America.^[19]
Apart from these sometimes little-known fossil forms, the phylogeny of the living squirrels is fairly straightforward. The three main lineages are the Ratufinae (Oriental giant squirrels), Sciurillinae and all other subfamilies. The Ratufinae contain a mere handful of living species in tropical Asia. The neotropical pygmy squirrel of tropical South America is the sole living member of the Sciurillinae. The third lineage, by far the largest, has a near-cosmopolitan distribution. This further supports the hypothesis that the common ancestor of all squirrels, living and fossil, lived in North America, as these three most ancient lineages seem to have radiated from there; if squirrels had originated in Eurasia, for example, one would expect quite ancient lineages in Africa, but African squirrels seem to be of more recent origin.^[19]
The main group of squirrels also can be split into three subgroups, which yield the remaining subfamilies. The Sciurinae contains the flying squirrels (Pteromyini) and the Sciurini, which among others contains the American tree squirrels; the former have often been considered a separate subfamily, but are now seen as a tribe of the Sciurinae. The pine squirrels (Tamiasciurus), on the other hand, are usually included with the main tree squirrel lineage, but appear to be about as distinct as the flying squirrels; hence, they are sometimes considered a distinct tribe, Tamiasciurini.^[20]
Two of the three subfamilies are of about equal size, containing between nearly 70 and 80 species each; the third is about twice as large. The Sciurinae contains arboreal (tree-living) squirrels, mainly of the Americas and to a lesser extent Eurasia. The Callosciurinae is most diverse in tropical Asia and contains squirrels which are also arboreal, but have a markedly different habitus and appear more "elegant", an effect enhanced by their often very colorful fur. The Xerinae?the largest subfamily?are made up from the mainly terrestrial (ground-living) forms and include the large marmots and the popular prairie dogs, among others, as well as the tree squirrels of Africa; they tend to be more gregarious than other squirrels, which do not usually live together in close-knit groups.^[19]
Basal and incertae sedis Sciuridae (all fossil)
Hesperopetes
Kherem
Lagrivea
Oligosciurus
Plesiosciurus
Prospermophilus
Sciurion
Similisciurus
Sinotamias
Vulcanisciurus
Subfamily Cedromurinae (fossil)
Subfamily Ratufinae ? Oriental giant squirrels (1 genus, 4 species)
Subfamily Sciurillinae ? neotropical pygmy squirrel (monotypic)
Subfamily Sciurinae
Tribe Sciurini ? tree squirrels (5 genera, about 38 species)
Tribe Pteromyini ? true flying squirrels (15 genera, about 45 species)
Subfamily Callosciurinae ? Asian ornate squirrels
Tribe Callosciurini (13 genera, nearly 60 species)
Tribe Funambulini palm squirrels (1 genus, 5 species)
Subfamily Xerinae ? terrestrial squirrels
Tribe Xerini ? spiny squirrels (3 genera, 6 species)
Tribe Protoxerini (6 genera, about 50 species)
Tribe Marmotini ? ground squirrels, marmots, chipmunks, prairie dogs, etc. (6 genera, about 90 species)
See also

[ Back to top ]
America n red squirrel
Eastern gray squirrel
Fox squirrel
Red squirrel
Squirrel relationship with humans
Tree squirrel
Western gray squirrel
Notes

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^ "squirrel, n.". The Oxford English Dictionary (2nd. ed.). Oxford University Press. 1989. http://dictionary.oed.com/cgi/entry/50235460. Retrieved 8 November 2010.
^ Whitaker & Elman (1980): 370
^ "Squirrel". Online Etymology Dictionary. http://www.etymonline.com/index.php?term=squirrel. Retrieved 2008-02-07.
^ Tree Squirrels, Wildlife Online, 23 November 2010.
^ ^a ^b ^c Milton (1984)
^ ^a ^b Squirrel Place - squirrels.org - Retrieved 14 December 2010.
^ "Squirrel" - HowStuffWorks
^ "Red & Gray Squirrels in Massachusetts". MassWildlife. Massachusetts Division of Fisheries and Wildlife. http://www.mass.gov/dfwele/dfw/wildlife/living/living_with_squirrels.htm. Retrieved 2012-04-03.
^ T?rm?l?, Timo; Vuorinen, Hannu; Hokkanen, Heikki (1980). "Timing of circadian activity in the flying squirrel in central Finland". Acta Theriologica 25 (32?42): 461?474. http://acta.zbs.bialowieza.pl/contents/?art=1980-025-32-42-0461. Retrieved 11 July 2007.
^ Richard W. Thorington, Katie Ferrell - Squirrels: the animal answer guide, JHU Press, 2006, ISBN 0801884020, 9780801884023, p. 75.
^ Friggens, M. (2002). "Carnivory on Desert Cottontails by Texas Antelope Ground Squirrels". The Southwestern Naturalist 47 (1): 132?133. doi:10.2307/3672818. JSTOR 3672818.
^ Bailey, B. (1923). "Meat-eating propensities of some rodents of Minnesota". Journal of Mammalogy 4: 129.
^ Wistrand, E.H. (1972). "Predation on a Snake by Spermophilus tridecemlineatus". American Midland Naturalist 88 (2): 511?512. doi:10.2307/2424389. JSTOR 2424389.
^ Whitaker, J.O. (1972). "Food and external parasites of Spermophilus tridecemlineatus in Vigo County, Indiana". Journal of Mammalogy 53 (3): 644?648. doi:10.2307/1379067. JSTOR 1379067.
^ Bradley, W. G. (1968). "Food habits of the antelope ground squirrel in southern Nevada". Journal of Mammalogy 49 (1): 14?21. doi:10.2307/1377723. JSTOR 1377723.
^ Morgart, J. R. (May 1985). "Carnivorous behavior by a white-tailed antelope ground squirrel Ammospermophilus leucurus". The Southwestern Naturalist 30 (2): 304?305. doi:10.2307/3670745. JSTOR 3670745.
^ Wilson, D.E.; Reeder, D.M. (2011). "Class Mammalia Linnaeus, 1758. In: Zhang, Z.-Q. (Ed.) Animal biodiversity: An outline of higher-level classification and survey of taxonomic richness". Zootaxa 3148: 56?60. http://mapress.com/zootaxa/2011/f/zt03148p060.pdf.
^ Emry, R. J.; Korth, W.W. (2007). "A new genus of squirrel (Rodentia, Sciuridae) from the mid-Cenozoic of North America". Journal of Vertebrate Paleontology 27 (3): 693?698. doi:10.1671/0272-4634(2007)27[693:ANGOSR]2.0.CO;2.
^ ^a ^b ^c Steppan & Hamm (2006)
^ Steppan et al. (2004), Steppan & Hamm (2006)
b>Squirrels belong to a large family of small or medium-sized rodents called the Sciuridae. The family includes tree squirrels, ground squirrels, chipmunks, marmots (including woodchucks), flying squirrels, and prairie dogs. Squirrels are indigenous to the Americas, Eurasia, and Africa, and have been introduced to Australia. The earliest known squirrels date from the Eocene and are most closely related to the mountain beaver and to the dormouse among living species.

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The word "squirrel", first specified in 1327, comes from Anglo-Norman esquirel from the Old French escurel, the reflex of a Latin word sciurus. This Latin word was borrowed from the Ancient Greek word s???????, skiour os, which means shadow-tailed, referring to the bushy appendage possessed by many of its members.^[1]^[2]
The native Old English word, acweorna, survived only into Middle English (as aquerne) before being replaced.^[3] The Old English word is of Common Germanic origin, with cognates such as German Eichhorn, Norwegian ekorn, Dutch eekhoorn, Swedish ekorre and Danish egern.
Characteristics

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Skull of an Oriental giant squirrel (g enus Ratufa) - note the classic sciuromorphous shape of the anterior zygomatic region.
Squirrels are generally small animals, ranging in size from the African pygmy squirrel at 7?10 cm (2.8?3.9 in) in length and just 10 g (0.35 oz) in weight, to the Alpine marmot which is 53?73 cm (21?29 in) long and weighs from 5 to 8 kg (11 to 18 lb). Squirrels typically have slender bodies with bushy tails and large eyes. Their fur is generally soft and silky, although much thicker in some species than others. The color of squirrels is highly variable between?and often even within?species.^[4]
The hind limbs are generally longer than the fore limbs, and they have four or five toes on each foot. Their paws on their fore feet include a thumb, although this is often poorly developed. The feet also have soft pads on the undersides.^[5]
Squirrels live in almost every habitat from tropical rainforest to semiarid desert, avoiding only the high polar regions and the driest of deserts. They are predominantly herbivorous, subsisting on seeds and nuts, but many will eat insects and even small vertebrates.^[6]
As their large eyes indicate, squirrels generally have an excellent sense of vision, which is especially important for tree-dwelling species. They also have very versatile and sturdy claws for grasping and climbing.^[7] Many also have a good sense of touch, with vibrissae on their heads and limbs.^[5]
The teeth of sciurids follow the typical rodent pattern, with large gnawing incisors that grow throughout life, and grinding cheek teeth set back behind a wide gap, or diastema. The typical dental formula for sciurids is $Upper: 1.0.1.3, lower: 1.0.1.3$ ^[]
Behavior

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Several species of squirrels have melanistic phases. In large parts of United States and Canada, the most common variety seen in urban areas is the melanistic form of the eastern gray squirrel.
Squirrels breed once or twice a year and give birth to a varying number of young after three to six weeks, depending on species. The you ng are born naked, toothless, and blind. In most species of squirrel, only the female looks after the young, which are weaned at around six to ten weeks of age and become sexually mature at the end of their first year. Ground-dwelling species are generally social animals, often living in well-developed colonies, but the tree-dwelling species are more solitary.^[5]
Ground and tree squirrels are typically diurnal or crepuscular,^[8] while flying squirrels tend to be nocturnal?except for lactating flying squirrels and their offspring, which have a period of diurnality during the summer.^[9]
Feeding
Squirrel eating a peanut
The Indian palm squirrel is the most common type of squirrel found in India.
Squirrels cannot digest cellulose, so must rely on foods rich in protein, carbohydrates, and fats. In temperate regions, early spring is the hardest time of year for squirrels, because buried nuts begin to sprout and are no longer available for the squirrel to eat, and new food sources have not become available yet. During these times, squirrels rely heavily on the buds of trees. Squirrels' diets consist primarily of a wide variety of plants, including nuts, seeds, conifer cones, fruits, fungi and green vegetation. However, some squirrels also consume meat, especially when faced with hunger.^[6] Squirrels have been known to eat insects, eggs, small birds, young snakes and smaller rodents. Indeed, some tropical species have shifted almost entirely to a diet of insects.^[10]
Predatory behavior has been noted by various species of ground squirrels, particularly the thirteen-lined ground squirrel.^[11] For example, Bailey, a scientist in the 1920s, observed a thirteen-lined ground squirrel preying upon a young chicken.^[12] Wistrand reported seeing this same species eating a freshly killed snake.^[13] Whitaker examined the stomachs of 139 thirteen-lined ground squirrels and found bird flesh in four of the specimens and the remains of a short-tailed shrew in one;^[14] Bradley, examining white-tailed antelope squirrels' stomachs, found at least 10% of his 609 specimens' stomachs contained some type of vertebrate, mostly lizards and rodents.^[15] Morgart observed a white-tailed antelope squirrel capturing and eating a silky pocket mouse.^[16]
Taxonomy

[ Back to top ]
Grizzled giant squirrel (Ratufa macroura) of the Ratufinae
Southern flying squirrel (Glaucomys volans) of the Pteromyini
Prevost's squirrel (Callosciurus prevosti) of the Callosciurini
Unstriped ground squirrel (Xerus rutilus) of the Xerini
Alpine marmot (Marmota marmota) of the Marmotini
The living squirrels are divided into five subfamilies, with about 58 genera and some 285 species.^[17] The oldest squirrel fossil, Hesperopetes, dates back to the Chadronian (late Eocene, about 40?35 million years ago) and is similar to modern flying squirrels.^[18]
A variety of squirrels, from the latest Eocene to the Miocene, could not be assigned with certainty to any living lineage. At least some of these probably were variants of the oldest basal "protosquirrels" (in the sense that they lacked the full range of living squirrels' autapomorphies). The distribution and diversity of such ancient and ancestral forms suggest the squirrels as a group may have originated in North America.^[19]
Apart from these sometimes little-known fossil forms, the phylogeny of the living squirrels is fairly straightforward. The three main lineages are the Ratufinae (Oriental giant squirrels), Sciurillinae and all other subfamilies. The Ratufinae contain a mere handful of living species in tropical Asia. The neotropical pygmy squirrel of tropical South America is the sole living member of the Sciurillinae. The third lineage, by far the largest, has a near-cosmopolitan distribution. This further supports the hypothesis that the common ancestor of all squirrels, living and fossil, lived in North America, as these three most ancient lineages seem to have radiated from there; if squirrels had originated in Eurasia, for example, one would expect quite ancient lineages in Africa, but African squirrels seem to be of more recent origin.^[19]
The main group of squirrels also can be split into three subgroups, which yield the remaining subfamilies. The Sciurinae contains the flying squirrels (Pteromyini) and the Sciurini, which among others contains the American tree squirrels; the former have often been considered a separate subfamily, but are now seen as a tribe of the Sciurinae. The pine squirrels (Tamiasciurus), on the other hand, are usually included with the main tree squirrel lineage, but appear to be about as distinct as the flying squirrels; hence, they are sometimes considered a distinct tribe, Tamiasciurini.^[20]
Two of the three subfamilies are of about equal size, containing between nearly 70 and 80 species each; the third is about twice as large. The Sciurinae contains arboreal (tree-living) squirrels, mainly of the Americas and to a lesser extent Eurasia. The Callosciurinae is most diverse in tropical Asia and contains squirrels which are also arboreal, but have a markedly different habitus and appear more "elegant", an effect enhanced by their often very colorful fur. The Xerinae?the largest subfamily?are made up from the mainly terrestrial (ground-living) forms and include the large marmots and the popular prairie dogs, among others, as well as the tree squirrels of Africa; they tend to be more gregarious than other squirrels, which do not usually live together in close-knit groups.^[19]
Basal and incertae sedis Sciuridae (all fossil)
Hesperopetes
Kherem
Lagrivea
Oligosciurus
Plesiosciurus
Prospermophilus
Sciurion
Similisciurus
Sinotamias
Vulcanisciurus
Subfamily Cedromurinae (fossil)
Subfamily Ratufinae ? Oriental giant squirrels (1 genus, 4 species)
Subfamily Sciurillinae ? neotropical pygmy squirrel (monotypic)
Subfamily Sciurinae
Tribe Sciurini ? tree squirrels (5 genera, about 38 species)
Tribe Pteromyini ? true flying squirrels (15 genera, about 45 species)
Subfamily Callosciurinae ? Asian ornate squirrels
Tribe Callosciurini (13 genera, nearly 60 species)
Tribe Funambulini palm squirrels (1 genus, 5 species)
Subfamily Xerinae ? terrestrial squirrels
Tribe Xerini ? spiny squirrels (3 genera, 6 species)
Tribe Protoxerini (6 genera, about 50 species)
Tribe Marmotini ? ground squirrels, marmots, chipmunks, prairie dogs, etc. (6 genera, about 90 species)
See also

[ Back to top ]
American red squirrel
Eastern gray squirrel
Fox squirrel
Red squirrel
Squirrel relationship with humans
Tree squirrel
Western gray squirrel
s, seeds, conifer cones, fruits, fungi and green vegetation. However, some squirrels also consume meat, especially when faced with hunger.^[6] Squirrels have been known to eat insects, eggs, small birds, young snakes and smaller rodents. Indeed, some tropical species have shifted almost entirely to a diet of insects.^[10]
Predatory behavior has been noted by various species of ground squirrels, particularly the thirteen-lined ground squirrel.^[11] For example, Bailey, a scientist in the 1920s, observed a thirteen-lined ground squirrel preying upon a young chicken.^[12] Wistrand reported seeing this same species eating a freshly killed snake.^[13] Whitaker examined the stomachs of 139 thirteen-lined ground squirrels and found bird flesh in four of the specimens and the remains of a short-tailed shrew in one;^[14] Bradley, examining white-tailed antelope squirrels' stomachs, found at least 10% of his 609 specimens' stomachs contained some type of vertebrate, mostly lizards and rodents.^[15] Morgart observed a white-tailed antelope squirrel capturing and eating a silky pocket mouse.^[16]
Taxonomy

[ Back to top ]
Grizzled giant squirrel (Ratufa macroura) of the Ratufinae
Southern flying squirrel (Glaucomys volans) of the Pteromyini
Prevost's squirrel (Callosciurus prevosti) of the Callosciurini
Unstriped ground squirrel (Xerus rutilus) of the Xerini
Alpine marmot (Marmota marmota) of the Marmotini
The living squirrels are divided into five subfamilies, with about 58 genera and some 285 species.^[17] The oldest squirrel fossil, Hesperopetes, dates back to the Chadronian (late Eocene, about 40?35 million years ago) and is similar to modern flying squirrels.^[18]
A variety of squirrels, from the latest Eocene to the Miocene, could not be assigned with certainty to any living lineage. At least some of these probably were variants of the oldest basal "protosquirrels" (in the sense that they lacked the full range of living squirrels' autapomorphies). The distribution and diversity of such ancient and ancestral forms suggest the squirrels as a group may have originated in North America.^[19]
Apart from these sometimes little-known fossil forms, the phylogeny of the living squirrels is fairly straightforward. The three main lineages are the Ratufinae (Oriental giant squirrels), Sciurillinae and all other subfamilies. The Ratufinae contain a mere handful of living species in tropical Asia. The neotropical pygmy squirrel of tropical South America is the sole living member of the Sciurillinae. The third lineage, by far the largest, has a near-cosmopolitan distribution. This further supports the hypothesis that the common ancestor of all squirrels, living and fossil, lived in North America, as these three most ancient lineages seem to have radiated from there; if squirrels had originated in Eurasia, for example, one would expect quite ancient lineages in Africa, but African squirrels seem to be of more recent origin.^[19]
The main group of squirrels also can be split into three subgroups, which yield the remaining subfamilies. The Sciurinae contains the flying squirrels (Pteromyini) and the Sciurini, which among others contains the American tree squirrels; the former have often been considered a separate subfamily, but are now seen as a tribe of the Sciurinae. The pine squirrels (Tamiasciurus), on the other hand, are usually included with the main tree squirrel lineage, but appear to be about as distinct as the flying squirrels; hence, they are sometimes considered a distinct tribe, Tamiasciurini.^[20]
Two of the three subfamilies are of about equal size, containing between nearly 70 and 80 species each; the third is about twice as large. The Sciurinae contains arboreal (tree-living) squirrels, mainly of the Americas and to a lesser extent Eurasia. The Callosciurinae is most diverse in tropical Asia and contains squirrels which are also arboreal, but have a markedly different habitus and appear more "elegant", an effect enhanced by their often very colorful fur. The Xerinae?the largest subfamily?are made up from the mainly terrestrial (ground-living) forms and include the large marmots and the popular prairie dogs, among others, as well as the tree squirrels of Africa; they tend to be more gregarious than other squirrels, which do not usually live together in close-knit groups.^[19]
Basal and incertae sedis Sciuridae (all fossil)
Hesperopetes
Kherem
Lagrivea
Oligosciurus
Plesiosciurus
Prospermophilus
Sciurion
Similisciurus
Sinotamias
Vulcanisciurus
Subfamily Cedromurinae (fossil)
Subfamily Ratufinae ? Oriental giant squirrels (1 genus, 4 species)
Subfamily Sciurillinae ? neotropical pygmy squirrel (monotypic)
Subfamily Sciurinae
Tribe Sciurini ? tree squirrels (5 genera, about 38 species)
Tribe Pteromyini ? true flying squirrels (15 genera, about 45 species)
Subfamily Callosciurinae ? Asian ornate squirrels
Tribe Callosciurini (13 genera, nearly 60 species)
Tribe Funambulini palm squirrels (1 genus, 5 species)
Subfamily Xerinae ? terrestrial squirrels
Tribe Xerini ? spiny squirrels (3 genera, 6 species)
Tribe Protoxerini (6 genera, about 50 species)
Tribe Marmotini ? ground squirrels, marmots, chipmunks, prairie dogs, etc. (6 genera, about 90 species)
See also

[ Back to top ]
American red squirrel
Eastern gray squirrel
Fox squirrel
Red squirrel
Squirrel relationship with humans
Tree squirrel
Western gray squirrel
Notes

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^ "squirrel, n.". The Oxford English Dictionary (2nd. ed.). Oxford University Press. 1 989. http://dictionary.oed.com/cgi/entry/50235460. Retrieved 8 November 2010.
^ Whitaker & Elman (1980): 370
^ "Squirrel". Online Etymology Dictionary. http://www.etymonline.com/index.php?term=squirrel. Retrieved 2008-02-07.
^ Tree Squirrels, Wildlife Online, 23 November 2010.
^ ^a ^b ^c Milton (1984)
^ ^a ^b Squirrel Place - squirrels.org - Retrieved 14 December 2010.
^ "Squirrel" - HowStuffWorks
^ "Red & Gray Squirrels in Massachusetts". MassWildlife. Massachusetts Division of Fisheries and Wildlife. http://www.mass.gov/dfwele/dfw/wildlife/living/living_with_squirrels.htm. Retrieved 2012-04-03.
^ T?rm?l?, Timo; Vuorinen, Hannu; Hokkanen, Heikki (1980). "Timing of circadian activity in the flying squirrel in central Finland". Acta Theriologica 25 (32?42): 461?474. http://acta.zbs.bialowieza.pl/contents/?art=1980-025-32-42-0461. Retrieved 11 July 2007.
^ Richard W. Thorington, Katie Ferrell - Squirrels: the animal answer guide, JHU Press, 2006, ISBN 0801884020, 9780801884023, p. 75.
^ Friggens, M. (2002). "Carnivory on Desert Cottontails by Texas Antelope Ground Squirrels". The Southwestern Naturalist 47 (1): 132?133. doi:10.2307/3672818. JSTOR 3672818.
^ Bailey, B. (1923). "Meat-eating propensities of some rodents of Minnesota". Journal of Mammalogy 4: 129.
^ Wistrand, E.H. (1972). "Predation on a Snake by Spermophilus tridecemlineatus". American Midland Naturalist 88 (2): 511?512. doi:10.2307/2424389. JSTOR 2424389.
^ Whitaker, J.O. (1972). "Food and external parasites of Spermophilus tridecemlineatus in Vigo County, Indiana". Journal of Mammalogy 53 (3): 644?648. doi:10.2307/1379067. JSTOR 1379067.
^ Bradley, W. G. (1968). "Food habits of the antelope ground squirrel in southern Nevada". Journal of Mammalogy 49 (1): 14?21. doi:10.2307/1377723. JSTOR 1377723.
^ Morgart, J. R. (May 1985). "Carnivorous behavior by a white-tailed antelope ground squirrel Ammospermophilus leucurus". The Southwestern Naturalist 30 (2): 304?305. doi:10.2307/3670745. JSTOR 3670745.
^ Wilson, D.E.; Reeder, D.M. (2011). "Class Mammalia Linnaeus, 1758. In: Zhang, Z.-Q. (Ed.) Animal biodiversity: An outline of higher-level classification and survey of taxonomic richness". Zootaxa 3148: 56?60. http://mapress.com/zootaxa/2011/f/zt03148p060.pdf.
^ Emry, R. J.; Korth, W.W. (2007). "A new genus of squirrel (Rodentia, Sciuridae) from the mid-Cenozoic of North America". Journal of Vertebrate Paleontology 27 (3): 693?698. doi:10.1671/0272-4634(2007)27[693:ANGOSR]2.0.CO;2.
^ ^a ^b ^c Steppan & Hamm (2006)
^ Steppan et al. (2004), Steppan & Hamm (2006)
References

[ Back to top ]
Milton, Katherine (1984): [Family Sciuridae]. In: Macdonald, D. (ed.): The Encyclopedia of Mammals: 612?623. Facts on File, New York. ISBN 0-87196-871-1
Steppan, Scott J. & Hamm, Shawn M. (2006): Tree of Life Web Project ? Sciuridae (Squirrels). Version of 13 May 2006. Retrieved 10 December 2007.
Steppan, Scot t J.; Storz, B.L. & Hoffmann, R.S. (2004): "Nuclear DNA phylogeny of the squirrels (Mammalia: Rodentia) and the evolution of arboreality from c-myc and RAG1" (pdf). Mol. Phyl. Evol. 30(3): 703?719. doi:10.1016/S1055-7903(03)00204-5
Thorington, R.W. & Hoffmann, R.S. (2005): Family Sciuridae. In: Mammal Species of the World ? A Taxonomic and Geographic Reference: 754?818. Johns Hopkins University Press, Baltimore.
Whitaker, John O. Jr. & Elman, Robert (1980): The Audubon Society Field Guide to North American Mammals (2nd ed.). Alfred Knopf, New York. ISBN 0-394-50762-2
External links

[ Back to top ]
Tree of Life: Sciuridae
Squirrel Tracks: How to id entify squirrel tracks in the wild
National Geographic link on Squirrels
List of names of squirrel taxa

Taxonomy

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The Family Sciuridae is further organized into finer groupings including:

Subfamily (2): Pteromyinae · Sciurinae

Tribe (9): Funambulini · Marmotini · Nannosciurini · Protoxerini · Ratufini · Sciurini · Tamiasciurini · Tamiini · Xerini

Subtribe (7): Funambulina · Funisciurina · Marmotina · Myosciurina · Sciurillina · Sciurina · Spermophilina

Genus (89): Aeretes · Aeromys · Aethosciurus · Ammospermophilus · Arctomyoides · Arctomys · Atlantoxerus · Belomys · Blackia · Callosciurus · Callospermophilus · Cedromus · Citellus · Cynomys · Douglassia · Dremomys · Eoglaucomys · Epixerus · Eupetaurus · Eutamias · Euxerus · Exilisciurus · Funambulus · Funisciurus · Geosciurus · Glaucomys · Glyphotes · Guerlinguetus · Heliosciurus · Heteroxerus · Hylopetes · Hylopetus · Hyosciurus · Iomys · Lariscus · Marmota · Menetes · Microsciurus · Miopetaurista · Miosciurus · Miospermophilus · Myosciurus · Nannosciurus · Neosciurus · Neotamias · Nototamias · Oligopetes · Oligospermophilus · Otospermophilus · Paenemarmota · Palaeosciurus · Parapaenemarmota · Paratamias · Paraxerus · Petaurillus · Petaurista · Petauristodon · Petinomys · Pliopetaurista · Pliopetes · Prosciurillus · Protosciurus · Protospermophilus · Protoxerus · Pteromys · Pteromyscus · Ratufa · Rheithrosciurus · Rhinosciurus · Rubrisciurus · Ruficaudus · Rupestes · Sciurillus · Sciurion · Sciuropterus · Sciurotamias · Sciurus · Similisciurus · Spermophilinus · Spermophilopsis · Spermophilus · Spermophulis · Sundasciurus · Syntheosciurus · Tamias · Tamiasciurus · Tamiops · Trogopterus · Xerus

Species: ZipcodeZoo has pages for 1,209 species and subspecies in the Family Sciuridae.

Genera

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Aeretes

The Groove-toothed flying squirrel or North Chinese flying squirrel (Aeretes melanopterus) is a species of rodent in the Sciuridae family. It is monotypic within the genus Aeretes.^[] It is endemic to China. Its natural habitat is temperate forests. [more]

Aeromys

Large black flying squirrels^[] (genus Aeromys) form a taxon of squirrels under the tribe Pteromyini. They are only found in South-east Asia. [more]

Aethosciurus

[more]

Ammospermophilus

The antelope squirrels or antelope ground squirrels are the genus Ammospermophilus of sciurids found in the southwestern United States and northern Mexico. [more]

Arctomyoides

[more]

Arctomys

[more]

Atlantoxerus

The Barbary Ground Squirrel (Atlantoxerus getulus) is a species of rodent in the Sciuridae family. It is monotypic within the genus Atlantoxerus.^[] It is endemic to Algeria, Morocco, and has also been introduced to the Canary Islands. Its natural habitats are subtropical or tropical dry shrubland, temperate grassland, and rocky areas. [more]

Belomys

The hairy-footed flying squirrel (Belomys pearsonii) is a flying squirrel found in the mountains of the eastern Himalaya, Southeast Asia, and southern China till the island of Taiwan. It lives at altitudes between 1500 and 2400 m above sea level. [more]

Blackia

[more]

Callosciurus

Callosciurus is a genus of squirrels collectively referred to as the "Beautiful squirrels". They are found mainly in Southeast Asia, though a few species also occur in Nepal, northeastern India, Bangladesh and southern China. Several of the species have settled on islands. In total, the genus contains 15 species and numerous varieties and subspecies. The genera Glyphotes, Rubrisciurus, and Tamiops have sometimes been included in Callosciurus. [more]

Callospermophilus

[more]

Cedromus

[more]

Citellus

A Genus in the Kingdom Animalia.^[1] [more]

Cynomys

Prairie dogs (genus Cynomys) are burrowing rodents native to the grasslands of North America. The five different species of prairie dogs are: black-tailed, white-tailed, Gunnison's, Utah and Mexican prairie dogs. They are a type of ground squirrel, found in the United States, Canada and Mexico. In Mexico, prairie dogs are found primarily in the northern states, which lie at the southern end of the Great Plains: northeastern Sonora, north and northeastern Chihuahua, northern Coahuila, northern Nuevo Le?n, and northern Tamaulipas. In the U.S., they range primarily to the west of the Mississippi River, though they have also been introduced in a few eastern locales. They are herbivorous. [more]

Douglassia

[more]

Dremomys

Red-cheeked Squirrels (genus Dremomys) form a taxon of squirrels under the subfamily Callosciurinae. They are only found in Asia. [more]

Eoglaucomys

The Kashmir Flying Squirrel (Eoglaucomys fimbriatus) is a species of rodent in the Sciuridae family. It is monotypic within the genus Eoglaucomys.^[] It is found in India and Pakistan. Its natural habitat is subtropical or tropical dry forests. It is threatened by habitat loss. [more]

Epixerus

Epixerus is a genus of in the Sciuridae family, found in Africa. It contains the following species: [more]

Eupetaurus

The Woolly Flying Squirrel (Eupetaurus cinereus) is the sole species placed in the genus Eupetaurus. Until recently scientific knowledge of this rare species was limited to 11 skins collected in the late nineteenth century. However, recent research has confirmed that it is still extant in Pakistani Kashmir. It is the longest member of the family Sciuridae and the most massive gliding animal known, but observations confirm that despite its size, it does glide effectively like other flying squirrels. [more]

Eutamias

Eutamias is a genus of chipmunks within the tribe Marmotini of the squirrel family. It includes a single living species, the Siberian chipmunk (Eutamias sibiricus). The genus is often treated as a subgenus of Tamias, which is now restricted to the eastern chipmunk of North America. Neotamias, which now includes the western North American chipmunks, has also been included in Eutamias. [more]

Euxerus

A Genus in the Kingdom Animalia.^[2] [more]

Exilisciurus

Exilisciurus is a genus of rodent in the Sciuridae family. It contains the following species: [more]

Funambulus

Funambulus is a genus of rodent in the Sciuridae family. [more]

Funisciurus

African striped squirrels (genus Funisciurus), or rope squirrels, form a taxon of squirrels under the subfamily Xerinae and the tribe Protoxerini. They are only found in western and central Africa. [more]

Geosciurus

A Genus in the Kingdom Animalia.^[3] [more]

Glaucomys

The two species of New World flying squirrels, genus Glaucomys, are the only species of found in North America. They are distributed from Alaska to Honduras. They are similar in many ways to the Eurasian flying squirrels in the genus Pteromys. The two species of New World flying squirrels can be easily distinguished on the basis of size and ventral pelage. Northern flying squirrels, Glaucomys sabrinus are larger and have belly hair that is dark at the base and white at the tip. Southern flying squirrels, Glaucomys volans, are smaller and have belly hairs that are completely white. [more]

Glyphotes

The Sculptor Squirrel (Glyphotes simus) is a species of rodent in the Sciuridae family. It is monotypic within the genus Glyphotes.^[] It is endemic to Malaysia. [more]

Guerlinguetus

A Genus in the Kingdom Animalia.^[4] [more]

Heliosciurus

Sun squirrels (genus Heliosciurus), form a taxon of squirrels under the subfamily Xerinae and the tribe Protoxerini. They are only found in sub-Saharan Africa. [more]

Heteroxerus

[more]

Hylopetes

Hylopetes is a genus of . [more]

Hylopetus

Hyosciurus

Hyosciurus is a genus of rodent in the Sciuridae family found in Indonesia. It contains the following species: [more]

Iomys

Iomys is a genus of in the Sciuridae family. Its species include: [more]

Lariscus

Striped ground squirrels (genus Lariscus) form a taxon of squirrels under the subfamily Callosciurinae. They are only found in Southeast Asia. Species in this genus include: [more]

Marmota

The marmots are generally large ground squirrels in the genus Marmota, of which there are 15 species. Those most often referred to as marmots tend to live in mountainous areas, such as the Alps, northern Apennines, Eurasian steppes, Carpathians, Tatras, and Pyrenees in Europe and northwestern Asia; the Rocky Mountains, Black Hills, Cascades, and Sierra Nevada in North America; and the Deosai Plateau in Pakistan and Ladakh in India. The groundhog, however, is also sometimes called a marmot, while the similarly sized, but more social, prairie dog is not classified in the genus Marmota but in the related genus Cynomys. [more]

Menetes

A Genus in the Kingdom unknown!.^[5] [more]

Microsciurus

Microsciurus or dwarf squirrels is a genus of squirrels from the tropical regions of Central and South America. [more]

Miopetaurista

Miosciurus

Miospermophilus

Myosciurus

The African Pygmy Squirrel (Myosciurus pumilio) is a species of rodent in the Sciuridae family. It is monotypic within the genus Myosciurus.^[] It is found in Cameroon, Republic of the Congo, Equatorial Guinea, and Gabon. Its natural habitat is subtropical or tropical moist lowland forests. It is threatened by habitat loss. It is the world's smallest squirrel measuring to about seventy milimeters, about the size of a mouse.^{[citation needed]} [more]

Nannosciurus

The black-eared squirrel (Nannosciurus melanotis) is a species of rodent in the Sciuridae family. It is monotypic within the genus Nannosciurus.^[] This tiny squirrel is found in forests in Borneo, Sumatra and Java. Except for its striking whitish and black facial markings, the black-eared squirrel resembles the least pygmy squirrel. [more]

Neosciurus

A Genus in the Kingdom Animalia.^[6] [more]

Neotamias

A Genus in the Kingdom Animalia.^[7] [more]

Nototamias

[more]

Oligopetes

Oligospermophilus

Otospermophilus

A Genus in the Kingdom Animalia.^[8] [more]

Paenemarmota

Palaeosciurus

Parapaenemarmota

Paratamias

Paraxerus

The African bush squirrels are a genus, Paraxerus, squirrels of the subfamily Xerinae. They are only found in Africa. [more]

Petaurillus

Pygmy flying squirrels (Petaurillus) are a genus of . [more]

Petaurista

Petaurista is a genus of rodent in the Sciuridae family. Squirrels in this family are generally large nocturnal squirrels. It contains the following species: [more]

Petauristodon

[more]

Petinomys

Petinomys is a genus of rodent in the Sciuridae family. It contains the following species: [more]

Pliopetaurista

Pliopetes

Prosciurillus

Prosciurillus is a genus of rodent in the Sciuridae family, found in Indonesia. It contains the following species: [more]

Protosciurus

Protospermophilus

Protoxerus

African Giant Squirrels ( Protoxerus) form a taxon of squirrels under the subfamily Sciurinae. They are only found in Africa. [more]

Pteromys

Commonly referred to as simply the Old World flying squirrels, the genus Pteromys is distributed across temperate Eurasia, Korean Peninsula and Japan. Although there are a host of flying squirrel genera in Asia (particularly southern Asia), Pteromys is the only one present in Europe. [more]

Pteromyscus

The Smoky Flying Squirrel, Pteromyscus pulverulentus, is a species of rodent in the Sciuridae family. It is monotypic within the genus Pteromyscus.^[] It is found in Brunei, Indonesia, peninsular Malaysia, and southern Thailand, but its range may be more extensive than currently mapped. Its natural habitat is subtropical or tropical dry forests. It is listed as endangered because of estimated population loss of 50% in past and future, judging from extensive and rapid habitat loss. [more]

Ratufa

Oriental giant squirrels are very large^[] tree squirrels from the genus Ratufa in the subfamily Ratufinae. They are a distinctive element of the fauna of south and southeast Asia. [more]

Rheithrosciurus

The tufted ground squirrel (Rheithrosciurus macrotis) is a species of rodent in the Sciuridae family. It is monotypic within the genus Rheithrosciurus.^[] It is found only on the island of Borneo, in Indonesia, Brunei and Malaysia. [more]

Rhinosciurus

The Shrew-faced Squirrel (Rhinosciurus laticaudatus), also known as the Long-nosed Squirrel, is a species of rodent in the Sciuridae family. It is monotypic within the genus Rhinosciurus.^[] It is found in forests in Peninsular Malaysia (possibly also in adjacent southern Thailand), Singapore, Sumatra and Borneo. This peculiar, terrestrial squirrel mainly feeds on insects and earthworms. It quite closely resembles a Tupaia treeshrew in appearance, but the Shrew-faced Squirrel can be recognized by its shorter gape, and shorter and more bushy tail. [more]

Rubrisciurus

The Red-bellied squirrel (Rubrisciurus rubriventer) is a species of squirrel. Until recently, it was described as a species in the genus Callosciurus, but since the 1990s it is generally placed in its own genus Rubrisciurus. It is endemic on the Indonesian island of Sulawesi. With a length of 25 cm (head and body), it is rather large for a squirrel. It lives in the tree tops of the rainforests of the island. [more]

Ruficaudus

Rupestes

A Genus in the Kingdom Animalia.^[9] [more]

Sciurillus

The Neotropical pygmy squirrel (Sciurillus pusillus) is a very small tree squirrel, being the only living species in the genus Sciurillus and the subfamily Sciurillinae. It is found in the lowland rainforests of Brazil, Colombia, Peru, French Guiana, Guyana and Suriname. [more]

Sciurion

Sciuropterus

A Genus in the Kingdom Animalia.^[10] [more]

Sciurotamias

Sciurotamias is a genus of in the Sciuridae family, found in China. It contains the following species: [more]

Sciurus

The genus Sciurus contains most of the common, bushy-tailed squirrels in North America, Europe, temperate Asia, Central America and South America. [more]

Similisciurus

Spermophilinus

[more]

Spermophilopsis

The Long-clawed Ground Squirrel (Spermophilopsis leptodactylus) is a species of rodent in the Sciuridae family. It is monotypic within the genus Spermophilopsis.^[] It is found in Afghanistan, Iran, Kazakhstan, Tajikistan, Turkmenistan, and Uzbekistan. [more]

Spermophilus

The genus Spermophilus is the largest genus of ground squirrels and the one that contains the species that are most common and familiar in . Members of the genus are found from western Europe to Siberia and Alaska to northern Mexico. The Eurasian species are sometimes called susliks (or sousliks). The latter name come from Russian ??????, suslik (compare also Polish: )^{[citation needed]} [more]

Spermophulis

Sundasciurus

Sundasciurus is a genus of rodent in the Sciuridae family. It contains two subgenera with 15 species: [more]

Syntheosciurus

Bangs's Mountain Squirrel (Syntheosciurus brochus) is a nearly unknown species of tree squirrel, that only lives in Costa Rica and Panama. It can be found in mountain rain forests at an altitude between 1,900 and 2,600 metres (6,200 and 8,500 ft), and lives mainly in the tree tops, but sometimes on the forest floor as well. One of its habitats is at the summit of the Po?s Volcano in Costa Rica, in a Clusia forest that is almost inaccessible for humans. [more]

Tamias

Chipmunks are small, striped squirrels. All species of chipmunks are found in North America, with the exception of the Siberian chipmunk, which is found in Asia. [more]

Tamiasciurus

Pine squirrels are of the genus Tamiasciurus. Currently only two species are classified in this genus, the American Red Squirrel T. hudsonicus and the Douglas Squirrel T. douglasii. Both are native to North America: pine squirrels can be found in the northern and western United States, most of Canada and Alaska. [more]

Tamiops

Asiatic striped squirrels are a genus, Tamiops, of squirrels in the subfamily Callosciurinae. They are only found in Asia. [more]

Trogopterus

The complex-toothed flying squirrel (Trogopterus xanthipes) is a flying squirrel found in the southern Chinese provinces Hubei, Hunan, Guizhou, Sichuan and Yunnan. Its name originates from the teeth, which differ from the other flying squirrels. The squirrel looks similar to other flying squirrels, most strikingly is a cluster of black hair at the bottom of the ear. The fur is grey-brown on top and white on bottom. Both its face and its tail are slightly red. The length of the body is about 30 cm, plus the tail which is another 30 cm long. The complex-toothed flying squirrel is an endangered species, both due to the destructions of forests as well as due to hunting. [more]

Xerus

African ground squirrels (genus Xerus) form a taxon of squirrels under the subfamily Xerinae. They are only found in Africa. There is another African ground squirrel of the genus Atlantoxerus, the Atlantoxerus getulus present in southwestern Morocco and northern Western Sahara. It is invasive in the Canary Islands since an introduction in 1971. [more]

At least 9 species and subspecies belong to the Genus Xerus.

More info about the Genus Xerus may be found here.

References

[ Back to top ]

Milton, Katherine (1984): [Family Sciuridae]. In: Macdonald, D. (ed.): The Encyclopedia of Mammals: 612?623. Facts on File, New York. ISBN 0-87196-871-1

Steppan, Scott J. & Hamm, Shawn M. (2006): Tree of Life Web Project ? Sciuridae (Squirrels). Version of 13 May 2006. Retrieved 10 December 2007.

Steppan, Scott J.; Storz, B.L. & Hoffmann, R.S. (2004): "Nuclear DNA phylogeny of the squirrels (Mammalia: Rodentia) and the evolution of arboreality from c-myc and RAG1" (pdf). Mol. Phyl. Evol. 30(3): 703?719. doi:10.1016/S1055-7903(03)00204-5

Thorington, R.W. & Hoffmann, R.S. (2005): Family Sciuridae. In: Mammal Species of the World ? A Taxonomic and Geographic Reference: 754?818. Johns Hopkins University Press, Baltimore.

Wh itaker, John O. Jr. & Elman, Robert (1980): The Audubon Society Field Guide to North American Mammals (2nd ed.). Alfred Knopf, New York. ISBN 0-394-50762-2

External links

[ Back to top ]

Tree of Life: Sciuridae

Squirrel Tracks: How to identify squirrel tracks in the wild

National Geographic link on Squirrels

List of names of squirrel taxa

Bibliography

[ Back to top ]

Gray, Proc. Zool. Soc. London, 1862: 145

Footnotes

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http://www.ubio.org/browser/details.php?namebankID=112576

http://www.ubio.org/browser/details.php?namebankID=112748

http://www.ubio.org/browser/details.php?namebankID=112772

http://www.ubio.org/browser/details.php?namebankID=112801

http://www.ubio.org/browser/details.php?namebankID=109305

http://www.ubio.org/browser/details.php?namebankID=113139

http://www.ubio.org/browser/details.php?namebankID=113141

http://www.ubio.org/browser/details.php?namebankID=113218

http://www.ubio.org/browser/details.php?namebankID=113430

http://www.ubio.org/browser/details.php?namebankID=113455

^ "squirrel, n.". The Oxford English Dictionary (2nd. ed.). Oxford University Press. 1989. http://dictionary.oed.com/cgi/entry/50235460. Retrieved 8 November 2010.

^ Whitaker & Elman (1980): 370

^ "Squirrel". Online Etymology Dictionary. http://www.etymonline.com/index.php?term=squirrel. Retrieved 2008-02-07.

^ Tree Squirrels, Wildlife Online, 23 November 201 0.

^ ^a ^b ^c Milton (1984)

^ ^a ^b Squirrel Place - squirrels.org - Retrieved 14 December 2010.

^ "Squirrel" - HowStuffWorks

^ "Red & Gray Squirrels in Massachusetts". MassWildlife. Massachusetts Division of Fisheries and Wildlife. http://www.mass.gov/dfwele/dfw/wildlife/living/living_with_squirrels.htm. Retrieved 2012-04-03.

^ T?rm?l?, Timo; Vuorinen, Hannu; Hokkanen, Heikki (1980). "Timing of circadian activity in the flying squirrel in central Finland". Acta Theriologica 25 (32?42): 461?474. http://acta.zbs.bialowieza.pl/contents/?art=1980-025-32-42-0461. Retrieved 11 July 2007.

^ Richard W. Thorington, Katie Ferrell - Squirrels: the animal answer guide, JHU Press, 2006, ISBN 0801884020, 9780801884023, p. 75.

^ Friggens, M. (2002). "Carnivory on Desert Cottontails by Texas Antelope Ground Squirrels". The Southwestern Naturalist 47 (1): 132?133. doi:10.2307/3672818. JSTOR 3672818.

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^ Whitaker, J.O. (1972). "Food and external parasites of Spermophilus tridecemlineatus in Vigo County, Indiana". Journal of Mammalogy 53 (3): 644?648. doi:10.2307/1379067. JSTOR 1379067.

^ Bradley, W. G. (1968). "Food habits of the antelope ground squirrel in southern Nevada". Journal of Mammalogy 49 (1): 14?21. doi:10.2307/1377723. JSTOR 1377723.

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^ Wilson, D.E.; Reeder, D.M. (2011). "Class Mammalia Linnaeus, 1758. In: Zhang, Z.-Q. (Ed.) Animal biodiversity: An outline of higher-level classification and survey of taxonomic richness". Zootaxa 3148: 56?60. http://mapress.com/zootaxa/2011/f/zt03148p060.pdf.

^ Emry, R. J.; Korth, W.W. (2007). "A new genus of squirrel (Rodentia, Sciuridae) from the mid-Cenozoic of North America". Journal of Vertebrate Paleontology 27 (3): 693?698. doi:10.1671/0272-4634(2007)27[693:ANGOSR]2.0.CO;2.

^ ^a ^b ^c Steppan & Hamm (2006)

^ Steppan et al. (2004), Steppan & Hamm (2006)

Sources

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