Eisspeedway

Speckled ground squirrel

Speckled ground squirrel
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Rodentia
Family: Sciuridae
Genus: Spermophilus
Species:
S. suslicus
Binomial name
Spermophilus suslicus
Subspecies

S. s. boristhenicus
S. s. guttatus
S. s. suslicus

Range of S. suslicus
  Resident
  Probably Extant, resident

The speckled ground squirrel or spotted souslik (Spermophilus suslicus) is a species of rodent in the family Sciuridae from Eastern Europe.[2] Spermophilus suslicus consists of three subspecies: S. s. boristhenicus, S. s. guttatus, and S. s. suslicus.[3] It is threatened by habitat loss.

Description

The speckled ground squirrel has dark-brown fur with white spots on its back and a short, thin tail. It grows to a length of 25 cm (10 in) and a weight of 280 g (10 oz). Its dental formula is 1.0.2.31.0.1.3. It is smaller and less social than many other ground squirrels of the genus Spermophilus.[4]

Taxonomy

Two populations separated geographically by the Dnieper River differ by diploid number, with those west of the Dnieper River, sometimes referred to as a sister species Spermophilus odessanus, having 36 chromosomes and those east, constituting Spermophilus suslicus sensu stricto, having 34.[1][5][6] Recent molecular phylogenetic data indicate that Palearctic ground squirrels are a complex, diverse group due to extensive genetic introgression and incomplete lineage sorting since their recent speciation during the Pleistocene epoch and require multiple lines of evidence to distinguish their interpopulation relationships.[7]

Distribution

It is found in Belarus, Moldova, Poland, European Russia, and Ukraine. Its natural habitat is temperate grassland and it is also found on cultivated ground. It is threatened by the loss and fragmentation of its habitat. Causes of habitat loss include the expansion of agriculture and forestry, the reduction of pasturing, the development and growth of cities, and industrial development. Also, in some areas it is hunted as an agricultural pest.[1][8]

The speckled ground squirrel's range in Poland and southern Russia has contracted markedly, with only 10% of its area in the mid-twentieth century currently remaining. At the current rate of contraction of its range, the speckled ground squirrel will soon be extirpated from Poland.[1]

Behavior

Individual in Odesa oblast, Ukraine

The speckled ground squirrel is a diurnal species which hibernates from October to April. It is active in the morning once the sun warms the area slightly, retreats to its underground den during the heat of the day, then reemerges late in the day for another feeding bout. It feeds mostly on grasses and cereals, although small vertebrates and arthropods are also eaten.[9]

Compared with other Spermophilus species, it lives in a relatively closed habitat with high grasses that block visibility during its active seasons.[4] Individuals live in separate burrows within a larger colony. These colonies can be up to over 160 individuals per ha. It mates between April and May. Gestation ranges from 23 to 26 days. Four to eight cubs are born per litter.[10] Sporadic hybridization occurs where S. suslicus occurs sympatrically with S. pygmaeus and S. citellus.[3]

Predators

Though there have been no quantitative studies on all the predators of S. suslicus, the weasel Mustela nivalis has been known to enter burrows and cause significant juvenile mortality, though it does not attack adults.[11] However, conspecific predation may be more of a threat to the juvenile speckled ground squirrel than interspecific predators. Though infanticide in the wild has not yet been reported, the speckled ground squirrel has been infanticidal in captivity. The killer can be male, female, or both, and either eats the young or attacks and leaves it to die.[11]

Alarm call

The speckled ground squirrel uses alarm calls for a variety of purposes. Primarily, the alarm call is used to warn conspecific squirrels of predators and to alert predators that they've been detected [4] Individual-specific alarm calls have been seen in Spermophilus suslicus which also contain age-related features but they lack the ability to distinguish between familiar and unfamiliar individuals nor can they distinguish sex.

Conservation

The population is believed to be experiencing continuing decline, with habitat fragmentation and loss occurring. In the 1996 IUCN Red List review, the speckled ground squirrel was listed as vulnerable, and in the 2008 and 2021 reviews, as near threatened. In the 2024 IUCN list update, it was listed as critically endangered, due to a 99% decline in the global population over the past 30 years. According to the IUCN, habitat destruction due to agricultural expansion, as well as climate change, puts the entire species at risk of extinction in the next 20–30 years.[1]

A relict enclave population in Poland is protected under national law. The species is protected under Appendix II of the Bern Convention.[1]

References

  1. ^ a b c d e f Rusin, M. (2024). "Spermophilus suslicus". IUCN Red List of Threatened Species. 2024: e.T20492A221789753. Retrieved 31 October 2024.
  2. ^ Thorington, R.W. Jr; Hoffman, R.S. (2005). "Family Sciuridae". In Wilson, D.E.; Reeder, D.M (eds.). Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Johns Hopkins University Press. p. 811. ISBN 978-0-8018-8221-0. OCLC 62265494.
  3. ^ a b Helgen, Kristopher M.; Cole, F. Russel; Helgen, Lauren E.; Wilson, Don E. (2009). "Generic revision in the holarctic ground squirrel genus". Journal of Mammalogy. 90 (2): 270–305. doi:10.1644/07-MAMM-A-309.1.
  4. ^ a b c Matrosova, Vera A.; Blumstein, Daniel T.; Volodin, Ilya A.; Volodina, Elena V. (March 2011). "The potential to encode sex, age, and individual identity in the alarm calls of three species of Marmotinae". Naturwissenschaften. 98 (3): 181–192. Bibcode:2011NW.....98..181M. doi:10.1007/s00114-010-0757-9. ISSN 0028-1042. PMC 3040313. PMID 21221515.
  5. ^ Zagorodniuk, I.V.; Fedorchenko, O.O. (1995). "АЛЛОПАТРИЧЕСКИЕ ВИДЫ СРЕДИ ГРЫЗУНОВ ГРУППЫ SPERMOPHILUS SUSLICUS (MAMMALIA)" [Allopatric Species among Rodent Group Spermophilus suslicus (Mammalia)] (PDF). Vestnik Zoologii (in Russian). 29 (5–6): 49–58. Retrieved 27 June 2024 – via Ukrainian Theriological Society. Note: Layout of the linked article is not the same as it was originally published.
  6. ^ Popova, L.V. (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. 420: 319–328. doi:10.1016/j.quaint.2015.10.104.
  7. ^ Simonov, E.; Lopatina, N.V.; Titov, S.V.; Ivanova, A.D.; Brandler, O. V.; Surim, V.L.; Matrosova, V.A.; Dvilis, A.E.; Oreshkova, N.V.; Kapustina, S.Yu.; Golenishchev, F.N.; Ermakov, O.A. (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. doi:10.1016/j.ympev.2024.108057. Art. No. 108057.
  8. ^ Shilova, S. A.; Neronov, V. V.; Shekarova, O. N.; Savinetskaya, L. E. (2010). "Dynamics of colonies of the speckled ground squirrel ( Spermophilus suslicus Guld., 1770) on the northern boundary of the habitat". Biology Bulletin. 37 (5): 532–536. Bibcode:2010BioBu..37..532S. doi:10.1134/S1062359010050134. S2CID 25563611.
  9. ^ Edelman, Andrew, ed. (2011). "Spermophilus suslicus". Encyclopedia of Life.
  10. ^ MacDonald, David; Priscilla Barret (1993). Mammals of Britain & Europe. Vol. 1. London: HarperCollins. p. 230. ISBN 0-00-219779-0.
  11. ^ a b Matrosova, Vera A.; Volodin, Ilya A.; Volodina, Elena V.; Babitsky, Andrey F. (2007). "Pups crying bass: vocal adaptation for avoidance of age-dependent predation risk in ground squirrels?". Behav Ecol Sociobiol. 62 (2): 181–191. doi:10.1007/s00265-007-0452-9. S2CID 5688475.

Media related to Spermophilus suslicus at Wikimedia Commons

Quelle: https://en.wikipedia.org/wiki/Speckled_ground_squirrel