''Spermophilus'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

ground squirrel Ground squirrels are rodents of the squirrel family (Sciuridae) that generally live on the ground or in burrows, rather than in trees like the tree squirrels. The term is most often used for the medium-sized ground squirrels, as the larger ones ar ...

s in the squirrel family. As traditionally defined the genus was very species-rich, ranging through Europe, Asia and North America, but this arrangement was found to be

paraphyletic Paraphyly is a taxonomic term describing a grouping that consists of the grouping's last common ancestor and some but not all of its descendant lineages. The grouping is said to be paraphyletic ''with respect to'' the excluded subgroups. In co ...

to the certainly distinct

prairie dog Prairie dogs (genus ''Cynomys'') are herbivorous burrowing Marmotini, ground squirrels native to the grasslands of North America. There are five recognized species of prairie dog: black-tailed prairie dog, black-tailed, white-tailed prairie dog ...

marmot Marmots are large ground squirrels in the genus ''Marmota'', with 15 species living in Asia, Europe, and North America. These herbivores are active during the summer, when they can often be found in groups, but are not seen during the winter, w ...

s, and antelope squirrels. As a consequence, all the former ''Spermophilus'' species of North America have been moved to other genera, leaving the European and Asian species as true ''Spermophilus'' (the only exceptions are two Asian ''

Urocitellus ''Urocitellus'' is a genus of ground squirrels. They were previously believed to belong to the much larger genus ''Spermophilus'', but DNA sequencing of the cytochrome ''b'' gene showed that this group was paraphyletic to the prairie dogs and m ...

''). Some species are sometimes called susliks (or sousliks). This name comes from Russian суслик, ''suslik''. In some languages, a derivative of the name is in common usage, for example ''suseł'' in Polish. The scientific name of this genus means "seed-lovers" (gr. σπέρμα ''sperma'', genitive σπέρματος ''spermatos'' – seed; φίλος ''philos'' – friend, lover).

Habitat and behavior

As typical ground squirrels, ''Spermophilus'' live in open habitats like grasslands, meadows,

steppe In physical geography, a steppe () is an ecoregion characterized by grassland plains without closed forests except near rivers and lakes. Steppe biomes may include: * the montane grasslands and shrublands biome * the tropical and subtropica ...

and semideserts, feed on the low plants, and use burrows as nests and refuge. They are diurnal and mostly live in colonies, although some species also can occur singly. They are found in both lowlands to highlands,

hibernate Hibernation is a state of minimal activity and metabolic reduction entered by some animal species. Hibernation is a seasonal heterothermy characterized by low body-temperature, slow breathing and heart-rate, and low metabolic rate. It is most ...

during the colder months (up to 8 months each year in some species) and in arid regions they may also aestivate during the summer or fall. The distributions of the various species are mostly separated, often by large rivers, although there are regions inhabited by as many as three species and rarely two species may even form mixed colonies. A few species are known to hybridize where their ranges come into contact.

Appearance

''Spermophilus'' are overall yellowish, light orangish, light brownish or greyish. Although many are inconspicuously mottled or spotted, or have orange markings on the head, overall they lack strong patterns, except in '' S. suslicus'', which commonly has brown upperparts with clear white spotting. Size varies with species and they have a head-and-body length of . Before hibernation the largest '' S. fulvus'' may weigh up to and the largest '' S. major'' up to almost , but they always weigh much less earlier in the year and other species are considerably smaller, mostly less than even in peak condition before hibernation. All have a fairly short tail that—depending on exact species—is around 10–45% of the length of the head-and-body.

Relationship with humans

Ground squirrels may carry fleas that transmit diseases to humans (see

Black Death The Black Death was a bubonic plague pandemic that occurred in Europe from 1346 to 1353. It was one of the list of epidemics, most fatal pandemics in human history; as many as people perished, perhaps 50% of Europe's 14th century population. ...

), and have been destructive in tunneling underneath human habitation.

Species

A generic revision was undertaken in 2007 by means of

phylogenetic In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as phylogenetic inference. It infers the relationship among organisms based on empirical dat ...

analyses using the

mitochondrial A mitochondrion () is an organelle found in the cells of most eukaryotes, such as animals, plants and fungi. Mitochondria have a double membrane structure and use aerobic respiration to generate adenosine triphosphate (ATP), which is used ...

gene

cytochrome b Cytochrome b is a protein found in the membranes of aerobic cells. In eukaryotic mitochondria (inner membrane) and in aerobic prokaryotes, cytochrome b is a component of respiratory chain complex III () — also known as the bc1 complex or ubiq ...

. This resulted in the splitting of ''Spermophilus'' into eight genera, which with the

s, and antelope squirrels are each given as numbered

clade In biology, a clade (), also known as a Monophyly, monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach t ...

s. The exact relations between the clades are slightly unclear. Among these, the exclusively

Palearctic The Palearctic or Palaearctic is a biogeographic realm of the Earth, the largest of eight. Confined almost entirely to the Eastern Hemisphere, it stretches across Europe and Asia, north of the foothills of the Himalayas, and North Africa. Th ...

species are retained as the genus ''Spermophilus sensu stricto'' (in the strictest sense). According to a 2024 genetic study the genus can be divided into four major clades that diverged during the

Late Miocene The Late Miocene (also known as Upper Miocene) is a sub-epoch of the Miocene epoch (geology), Epoch made up of two faunal stage, stages. The Tortonian and Messinian stages comprise the Late Miocene sub-epoch, which lasted from 11.63 Ma (million ye ...

. * ''Spermophilus

sensu stricto ''Sensu'' is a Latin word meaning "in the sense of". It is used in a number of fields including biology, geology, linguistics, semiotics, and law. Commonly it refers to how strictly or loosely an expression is used in describing any particular c ...

'',

Old World The "Old World" () is a term for Afro-Eurasia coined by Europeans after 1493, when they became aware of the existence of the Americas. It is used to contrast the continents of Africa, Europe, and Asia in the Eastern Hemisphere, previously ...

ground squirrels :East Asian clade :* Alashan ground squirrel, ''Spermophilus alashanicus'' :* Daurian ground squirrel, ''Spermophilus dauricus'' :Asia Minor/European clade :*

European ground squirrel The European ground squirrel (''Spermophilus citellus''), also known as the European souslik, is a species from the squirrel family, Sciuridae. It is among the few European species in the genus ''Spermophilus''. Like all squirrels, it is a membe ...

, ''Spermophilus citellus'' :* Podolian souslik ''(Spermophilus odessanus'') :* Speckled ground squirrel, ''Spermophilus suslicus'' :* Taurus ground squirrel, ''Spermophilus taurensis'' :* Asia Minor ground squirrel, ''Spermophilus xanthoprymnus'' :''Pygmaeus''-clade :* Caucasian Mountain ground squirrel, ''Spermophilus musicus'' :* Little ground squirrel, ''Spermophilus pygmaeus'' :''Colobotis''-clade :* Brandt's ground squirrel, ''Spermophilus brevicauda'' :* Red-cheeked ground squirrel, ''Spermophilus erythrogenys'' :* Yellow ground squirrel, ''Spermophilus fulvus'' :* Russet ground squirrel, ''Spermophilus major'' :* Pallid ground squirrel, ''Spermophilus pallidicauda'' :* ''

Spermophilus ralli The relict ground squirrel (''Spermophilus relictus'') is a species of rodent in the family Sciuridae. It is found in Kazakhstan, Kyrgyzstan and Uzbekistan. It is thought to be synonymous with ''Spermophilus ralli'', whose name was formerly used ...

'' :* Relict ground squirrel, ''Spermophilus relictus'' :* '' Spermophilus selevinus'' :* '' Spermophilus vorontsovi''

Prehistoric species

Discovery and examination of one of the best preserved Eurasian ground squirrel fossils yet recovered allowed the study of many previously unknown aspects of ground squirrel cranial anatomy, and prompted a critical reassessment of their phylogenetic position. As a result, three

Pleistocene The Pleistocene ( ; referred to colloquially as the ''ice age, Ice Age'') is the geological epoch (geology), epoch that lasted from to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fin ...

species previously considered members of the ''

'' genus were moved to ''Spermophilus'': :* †'' Spermophilus nogaici'' :* †'' Spermophilus polonicus'' :* †'' Spermophilus primigenius'' In addition to the recent species, three now-extinct species are known from the Pleistocene of Europe: '' Spermophilus citelloides'' is known from the Middle Pleistocene to early Holocene of central Europe. It appears to be most closely related to the living ''S. suslicus''. '' Spermophilus severskensis'' is known from the late Pleistocene ( Weichselian) of the Desna area, Ukraine. It appears to have been a highly specialised grazer and close relative of the living ''S. pygmaeus''. '' Spermophilus superciliosus'' is known from the Middle Pleistocene to reportedly the early 20th century, with a vast range across much of Europe, from southern England to the

Volga The Volga (, ) is the longest river in Europe and the longest endorheic basin river in the world. Situated in Russia, it flows through Central Russia to Southern Russia and into the Caspian Sea. The Volga has a length of , and a catchment ...

and the

Ural Mountains The Ural Mountains ( ),; , ; , or simply the Urals, are a mountain range in Eurasia that runs north–south mostly through Russia, from the coast of the Arctic Ocean to the river Ural (river), Ural and northwestern Kazakhstan.

. It was similar in size to the recent ''S. major'', and a probable ancestor of ''S. fulvus''.

References

External links

{{Authority control Rodents of Europe Mammals of North America Mammals of Asia Rodent genera Taxa named by Frédéric Cuvier