Spermophilus

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Spermophilus
Temporal range: Middle Miocene - Recent
Asia Minor Ground Squirrel.jpg
Spermophilus xanthoprymnus
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Rodentia
Family: Sciuridae
Tribe: Marmotini
Genus: Spermophilus
F. Cuvier, 1825
Type species
Mus citellus
Species

See text.

Spermophilus, also known as the Old World ground squirrels, is an Old World genus of ground squirrels in the squirrel family (Sciuridae). [1] Formerly, the genus was more species rich, but it has since been reduced to contain only species from Eurasia, with many former species having been moved to other genera. The 18 known species are distributed across the Eurasian steppe belt and adjacent regions between Central Europe and Manchuria. They inhabit steppe and comparable short grassland habitats, including airports, as well semi-deserts and, in some cases, agricultural fields. Their diet is dominated by seeds, grasses, forbs, roots and tubers, but may also include small invertebrates. Spermophilus live in colonial burrows, and spend much of the year in hibernation and, in dry regions, aestivation. Some species are 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). [2]

Contents

Ecology and behavior

As typical ground squirrels, Spermophilus live in open habitats like grasslands, meadows, steppe and semideserts throughout the Eurasian steppe and adjacent regions, feed on the low plants, and use burrows as nests and refuge. [3] [4] They are diurnal and mostly live in colonies, although some species also can occur singly. [5] They are found in both lowlands to highlands, hibernate during the colder months (up to c. 812 months each year in some species) and in arid regions they may also aestivate during the summer or fall. [3] The distributions of the various species are mostly separated, often by large rivers or mountain ranges, although there are regions inhabited by as many as three species and rarely two species may even form mixed colonies. [3] Generally, however, interspecific competition is intense and thus, sufficient differences in size (as per Hutchinson's rule) seem to be a necessary precondition for sympatry. [6] A few species are known to hybridize where their ranges come into contact. [3]

In contrast to most other, smaller grassland rodents, such as voles, gerbils or the steppe pika, but like other ground squirrels, Spermophilus are mainly active during the day, and rely on their good vision and their agility to detect and evade predators. Therefore, Spermophilus require open and low-growing habitats, and can cope well even with overgrazing. [7] On the contrary, dense vegetation makes them vulnerable to predation by their many predators, including the steppe and eastern imperial eagles, and steppe and marbled polecats, often rendering them dependent on the presence of large grazing animals. [6] [8] [9] Like other colonial ground squirrels, Spermophilus use high-pitched calls to communicate and warn colony members of predators. [10]

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 and S. odessanus , which commonly have brown upperparts with clear white spotting. [3] Size varies with species and they have a head-and-body length of c.17–40 cm (6.7–15.7 in). Before hibernation the largest S. fulvus may weigh up to 2 kg (4.4 lb) and the largest S. major up to almost 1.4 kg (3.1 lb), but they always weigh much less earlier in the year and other species are considerably smaller, mostly less than 0.5 kg (1.1 lb) even in peak condition before hibernation. [3] All have a fairly short tail that—depending on exact species—is around 10–45% of the length of the head-and-body. [3]

Taxonomy

As traditionally defined the genus was very species-rich, ranging through Europe, Asia and North America, but this arrangement was found to be paraphyletic to the certainly distinct prairie dogs ( Cynomys ), marmots ( Marmota ), and antelope squirrels ( Ammospermophilus ). 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 being the two Asian Urocitellus species). [11] The exact relations between these clades are slightly unclear. [12] According to Simonov et al. (2024), Spermophilus consists of 18 species. Also according to this study, the genus can be divided into four major clades that diverged during the Late Miocene. [4]

CladeImageNameCommon nameDistribution
East Asian clade
Spermophilus alashanicus 381342585.jpg
Spermophilus alashanicus Alashan ground squirrel Northern China west of the Yellow River.
Spermophilus dauricus Daurian ground squirrelNorthern China and Manchuria between the Yellow River and the Amur River.
Pygmaeus clade
Suslik v pole.jpg
Spermophilus musicus Caucasus Mountain ground squirrelsouthern Pontic-Caspian steppe between the Dnieper and Volga rivers; Crimea.
Spermophilus pygmaeus 58814806.jpg
Spermophilus pygmaeus Little ground squirrelnorthern Central Asia east of the Volga.
Europe/Asia Minor clade
European souslik (Spermophilus citellus) Obrovisko 3.jpg
Spermophilus citellus European ground squirrel Balkan Peninsula to the Czech Republic and Poland, Moldova and western Ukraine.
Spotted souslik (Spermophilus odessanus).jpg
Spermophilus odessanus Polonian ground squirrel Eastern Europe between the Carpathian Mountains and the Dnieper River.
Spermophilus suslicus 384911573.jpg
Spermophilus suslicus Speckled ground squirrelNorthern Pontic steppe between the Dnieper and Volga rivers.
Spermophilus taurensis.jpg
Spermophilus taurensis Taurus ground squirrelSouth-central Anatolia.
Asia Minor Ground Squirrel.jpg
Spermophilus xanthoprymnus Anatolian ground squirrel South-western, central and eastern Anatolia; Armenian highlands.
Colobotis clade Spermophilus brevicauda Brandt's ground squirrelBorder region between Kazakhstan and China along the Tian Shan.
Spermophilus erythrogenys 392429402.jpg
Spermophilus erythrogenys Red-cheeked ground squirrelWestern Siberia between the Irtysh and Ob rivers.
Spermophilus fulvus Baikonur 02.jpg
Spermophilus fulvus Yellow ground squirrelCentral Asia and the northern Iranian Plateau.
Spermophilus major 203118180.jpg
Spermophilus major Russet ground squirrel Ural Mountains between the Volga and Tobol rivers.
Spermophilus pallicauda Pale-bellied ground squirrelMongolia and Gobi Desert Altai Mountains.
Spermophilus nilkaensis Tian Shan ground squirrelEndemic to the Tian Shan.
Spermophilus relictus in Ertosh.jpg
Spermophilus relictus Relict ground squirrelCentral Asia between the Tian Shan and the Pamir Mountains.
Spermophilus seleveni Central Asia between the Tobol and Irtysh rivers, Lake Balkhash and the Tian Shan.
Spermophilus erythrogenys 121075441.jpg
Spermophilus vorontsovi Western Siberia between the Ob and the Kuznetsk Alatau Mountains.

Extinct 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. [13] As a result, three Pleistocene species previously considered members of the Urocitellus genus were moved to Spermophilus:[ citation needed ]

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. [14]

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. [6]

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 and the Ural Mountains. It was similar in size to the recent S. major, and a probable ancestor of S. fulvus. [15]

Relationship with humans

Ground squirrels may carry fleas that transmit diseases to humans (see Black Death), and have been destructive in tunneling underneath human habitation. [16]

References

  1. Wilson, D. E.; Reeder, D. M., eds. (2005). Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Baltimore: Johns Hopkins University Press. ISBN   978-0-8018-8221-0. OCLC   62265494.
  2. Palmer, T.S. (1904). "Index Generum Mammalium: a List of the Genera and Families of Mammals". North American Fauna. 23: 639. doi: 10.3996/nafa.23.0001 . Retrieved 9 February 2018.
  3. 1 2 3 4 5 6 7 Kryštufek, B.; B. Vohralík (2012). "Taxonomic revision of the Palaearctic rodents (Rodentia). Part 1 (Eutamias and Spermophilus)". Lynx, N. S. (Praha). 43: 17–111.
  4. 1 2 3 Simonov, Evgeniy; Lopatina, Natalia V.; Titov, Sergey V.; Ivanova, Anastasiya D.; Brandler, Oleg V.; Surin, Vadim L.; Matrosova, Vera A.; Dvilis, Alisa E.; Oreshkova, Nataliya V.; Kapustina, Svetlana Yu.; Golenishchev, Fedor N.; Ermakov, Oleg A. (1 June 2024). "Traditional multilocus phylogeny fails to fully resolve Palearctic ground squirrels (Spermophilus) relationships but reveals a new species endemic to West Siberia" . Molecular Phylogenetics and Evolution. 195 108057. Bibcode:2024MolPE.19508057S. doi:10.1016/j.ympev.2024.108057. ISSN   1055-7903. PMID   38471598.
  5. Smith, A.T.; Y. Xie, eds. (2008). A Guide to the Mammals of China. Princeton University Press. pp. 193–196. ISBN   978-0-691-09984-2.
  6. 1 2 3 Popova, L. V.; Maul, L. C.; Zagorodniuk, I. V.; Veklych, Yu. M.; Shydlovskiy, P. S.; Pogodina, N. V.; Bondar, K. M.; Strukova, T. V.; Parfitt, S. A. (10 March 2019). "'Good fences make good neighbours': Concepts and records of range dynamics in ground squirrels and geographical barriers in the Pleistocene of the Circum-Black Sea area" . Quaternary International. Bridging Europe and Asia: Quaternary stratigraphy and paleolithic human occupation. 509: 103–120. Bibcode:2019QuInt.509..103P. doi:10.1016/j.quaint.2018.03.023. ISSN   1040-6182.
  7. Cao, Chan; Shuai, Ling-Ying; Xin, Xiao-Ping; Liu, Zhi-Tao; Song, Yan-Ling; Zeng, Zhi-Gao (2016). "Effects of cattle grazing on small mammal communities in the Hulunber meadow steppe". PeerJ. 4 e2349. doi: 10.7717/peerj.2349 . ISSN   2167-8359. PMC   5012293 . PMID   27635323.
  8. Koshkina, Alyona; Freitag, Martin; Grigoryeva, Irina; Hölzel, Norbert; Stirnemann, Ingrid; Velbert, Frederike; Kamp, Johannes (2023). "Post-Soviet fire and grazing regimes govern the abundance of a key ecosystem engineer on the Eurasian steppe, the yellow ground squirrel Spermophilus fulvus". Diversity and Distributions. 29 (3): 395–408. Bibcode:2023DivDi..29..395K. doi: 10.1111/ddi.13668 . ISSN   1472-4642.
  9. Surkova, Elena; Popov, Sergey; Tchabovsky, Andrey (2019). "Rodent burrow network dynamics under human-induced landscape transformation from desert to steppe in Kalmykian rangelands" . Integrative Zoology. 14 (4): 410–420. doi:10.1111/1749-4877.12392. ISSN   1749-4877. PMID   30983144.
  10. Matrosova, Vera A.; Schneiderová, Irena; Volodin, Ilya A.; Volodina, Elena V. (1 January 2012). "Species-specific and shared features in vocal repertoires of three Eurasian ground squirrels (genus Spermophilus)" . Acta Theriologica. 57 (1): 65–78. doi:10.1007/s13364-011-0046-9. ISSN   2190-3743.
  11. Helgen Kristofer M; et al. (2009). "Generic revision in the Holarctic ground squirrel genus Spermophilus". Journal of Mammalogy. 90 (2): 270–305. doi: 10.1644/07-mamm-a-309.1 .
  12. Helgen, Kristofer M.; Cole, F. Russel; Helgen, Lauren E. & Wilson, Don E (2009). "Generic Revision in the Holarctic Ground Squirrel Genus Spermophilus". Journal of Mammalogy. 90 (2): 270–305. doi: 10.1644/07-MAMM-A-309.1 .
  13. Maxim V. Sinitsa; Natalia V. Pogodina; Lyudmila Y. Кryuchkova (2019). "The skull of Spermophilus nogaici (Rodentia: Sciuridae: Xerinae) and the affinities of the earliest Old World ground squirrels". Zoological Journal of the Linnean Society. 186 (3): 826–864. doi:10.1093/zoolinnean/zly092.
  14. Sinitsa, Maxim V.; Virág, Attila; Pazonyi, Piroska; Knitlová, Markéta (29 October 2019). "Redescription and phylogenetic relationships of Spermophilus citelloides (Rodentia: Sciuridae: Xerinae), a ground squirrel from the Middle Pleistocene – Holocene of Central Europe" . Historical Biology. 33: 19–39. doi:10.1080/08912963.2019.1677640. ISSN   0891-2963. S2CID   208578857.
  15. Popova, L. V. (28 October 2016). "Evolutionary lineage of Spermophilus superciliosus – S. fulvus (Rodentia, Sciuridae) in the quaternary of the Dnieper area: An ability of a biostratigraphical implication". Quaternary International. The Quaternary of the Urals: Global trends and Pan-European Quaternary records. 420: 319–328. Bibcode:2016QuInt.420..319P. doi: 10.1016/j.quaint.2015.10.104 . ISSN   1040-6182.
  16. Encyclopædia Britannica