Unstriped ground squirrel

{{Short description|Species of rodent}} {{Speciesbox | name = Unstriped ground squirrel | image = Xerus rutilus.jpg | status = LC | status_system = IUCN3.1 | status_ref = <ref name=iucn>{{cite iucn |author=Cassola, F. |year=2016 |errata=2017 |title=''Xerus rutilus'' |volume=2016 |article-number=e.T23147A115167688 |doi=10.2305/IUCN.UK.2016-3.RLTS.T23147A22253040.en |access-date=13 December 2025}}</ref> | parent_authority = Hemprich & Ehrenberg, 1833 | display_parents = 2 | genus = Xerus | species = rutilus | authority = (Cretzschmar, 1828) | synonyms = }}

The '''unstriped ground squirrel''' ('''''Xerus rutilus''''') is a species of rodent (order Rodentia) in the family Sciuridae. It is the only member of the genus '''''Xerus'''''. It is found in Djibouti, Eritrea, Ethiopia, Kenya, Somalia, Sudan, Tanzania, and Uganda. Its natural habitats are dry savanna and subtropical or tropical dry shrubland.

==Description==

The unstriped ground squirrel is brownish or tawny in color with a lighter colored front. As the name suggests the ''X. rutilus'' differs from other species of African ground squirrel by not having dorsal-running longitudinal white stripes. The eye is ringed with white hair (all hair being coarse in observed specimens). Their small head and body measure on average {{convert|225.8|mm}} long with an average tail length of {{convert|172|mm|abbr=on}}. This tail is flat in appearance. Body weight varies across studies and habitats and ranges from {{convert|257.7|to|420|g}}.<ref>{{cite journal|author=Coe, M. |year=1972|title= The South Turkana expedition. Scientific papers IX. Ecological studies of the small mammals of South Turkana |journal=Geographical Journal|volume= 138|issue=3 |pages= 316–338 |doi=10.2307/1795439 |jstor=1795439 |bibcode=1972GeogJ.138..316C }}</ref><ref name="OShea1991">{{cite journal | last1 = O'Shea | first1 = T. J. | year = 1991 | title = ''Xerus rutilus'' | journal = Mammalian Species | issue = 370| pages = 1–5 | doi = 10.2307/3504277 | jstor = 3504277 | doi-access = free }}</ref> The length of the hind foot is 35–49 mm with a braincase measuring only 24–25 mm. The length of the mandible is variable in the range of 31.0 to 33.9 mm.<ref name= "OShea1991"/><ref>{{cite journal | last1 = Michaux | first1 = J. | last2 = Hautier | first2 = L. | last3 = Simonin | first3 = T. | last4 = Vianey-Liaud | first4 = M. | year = 2008 | title = Phylogeny, adaptation and mandible shape in Sciuridae (Rodentia, Mammalia) | journal = Mammalia | volume = 72 | issue = 4| pages = 286–296 | doi=10.1515/mamm.2008.049| s2cid = 84441705 }}</ref>

''Xerus rutilus'' is a member of the Xerini tribe, but differs from its sister group ''Xerus daamsi''. Both are separate and distinct from the North African equivalent ''Atlantoxerus''.<ref name="denys">{{cite journal |last1=Denys |first1=C. |last2=Viriot |first2=L. |last3=Daams |first3=R. |last4=Pelaez-Campomanes |first4=P. |last5=Vignaud |first5=P. |last6=Andossa |first6=L. |last7=Brunet |first7=M. |year=2003 |title=A new Pliocene Xerine sciurid (Rodentia) from Kossom Bougoudi, Chad |journal=Journal of Vertebrate Paleontology |volume=23 |issue=3 |pages=676–687 |doi=10.1671/2311 |bibcode=2003JVPal..23..676D |s2cid=86163438}}</ref> Vibrissae (whiskers) length and brain size are both smaller than arboreal squirrels of the region, but are similar to other terrestrial squirrels.<ref name= "OShea1991"/>

No significant sexual dimorphism is noted in ''X. rutilus''.

==Local and indigenous names== In Tigrinya language: {{lang|ti|ምጹጽላይ}} or {{lang|ti|ጨጨራ}} (mitsutsilay, chechera).<ref name= "Aerts2019">{{cite book |last1=Aerts |first1=Raf |chapter=Forest and woodland vegetation in the highlands of Dogu'a Tembien|editor= Nyssen J.|editor2= Jacob, M.|editor3= Frankl, A. |title= Geo-trekking in Ethiopia's Tropical Mountains - The Dogu'a Tembien District |date=2019 |publisher=SpringerNature |isbn=978-3-030-04954-6 |url=https://www.springer.com/gp/book/9783030049546 |access-date=18 June 2019}}</ref>

In Turkana: {{IPA|tuv|ekuɲuk|}}, borrowed further in Daasanach: {{IPA|dsh|ɲékuɲug|}}<ref>{{cite book|first=Mauro|last=Tosco|title=The Dhaasanac Language|year=2001|publisher=Rudiger Köppe|location=Köln|page=576}}</ref>

==Ecology==

===Range and habitat===

The unstriped ground squirrel is endemic to Ethiopia,<ref name= "Aerts2019"/> Kenya, Sudan, Tanzania, Djibouti, Eritrea and Uganda and probably extant in Somalia.<ref name=iucn/> Its natural habitats include dry (arid) savanna and subtropical or tropical dry shrubland. Populations occupy many overlapping regions with its sister group, the African striped ground squirrel (''Euxerus erythropus''), in northeastern Africa.<ref>{{cite journal | last1 = Herron | first1 = M. D. | last2 = Waterman | first2 = J. M. | last3 = Parkinson | first3 = C. L. | year = 2005 | title = Phylogeny and historical biogeography of African ground squirrels: the role of climate change in the evolution of Xerus | journal = Molecular Ecology | volume = 14 | issue = 9| pages = 2773–2788 | doi = 10.1111/j.1365-294X.2005.02630.x | pmid=16029477| bibcode = 2005MolEc..14.2773H | s2cid = 35874572 }}</ref> ''X. rutilus'' dig and occupy burrows in generally arid conditions.<ref name="OShea1991"/>

===Diet and foraging===

The unstriped ground squirrels demonstrate diurnality with an omnivorous diet consisting of leaves, tree fruits (Adansonia digital), seeds (Commiphora and Acacia trees), other plant materials, and insects.<ref name= "OShea1991"/> Studies show that ''X. rutilus'' is unaffected by poisonous tannins and to some degree eats oxalic-containing foods. ''X. rutilus'' has been shown to be uniquely efficient in its capacity to forage for food. This ability is not diminished across a variety of different environments, including those with a poor to moderate food supply.<ref name="azoo">{{cite journal|last1=Fanson |first1=Benjamin G. |last2=Fanson |first2=Kerry V. |last3=Brown |first3=Joel S. |title=Ecological factors affecting the foraging behaviour of ''Xerus rutilus''|year=2010|journal= African Zoology|volume= 45|issue=2|pages= 265–272 |doi=10.3377/004.045.0205 }}</ref>

==Behavior==

===Burrows===

''X. rutilus'' are mainly solitary. They live in burrow systems with one or two adults with overlapping home areas. In times of danger unstriped ground squirrel may dive into a foreign burrow for safety. Unstriped ground squirrels permit non-resident squirrels to enter their burrows, including those of other species (''E. erythropus'').<ref name= "OShea1991"/> They spend most of their waking hours outside their burrows, but utilize them for sleep and shelter from the elements. They move around quite often during the day, but remain sedentary.<ref name=hubert>{{cite journal | last1 = Hubert | first1 = B | year = 1978 | title = Modern rodent fauna of the Lower Omo Valley, Ethiopia | journal = Bulletin of Carnegie Museum of Natural History | volume = 6 | pages = 109–112 }}</ref><ref name=Martin>{{cite journal | last1 = Martin | first1 = G | year = 1986 | title = Small mammals of arid savanna and montane sites in northern Kenya | journal = Journal of Arid Environments | volume = 11 | issue = 2| pages = 173–180 | doi = 10.1016/S0140-1963(18)31228-X | bibcode = 1986JArEn..11..173M }}</ref>

===Dominance hierarchy===

Although not territorial, a dominance hierarchy exists with male squirrels being dominant over females and younger squirrels. ''X. rutilus'' demonstrate dominance via vocalization, tail displays, and physical lunges.<ref name= "OShea1991"/><ref name= "hubert"/><ref name= "Martin"/>

==Physiology==

===Thermoregulation===

Unstriped ground squirrels generally reside in hot arid conditions and compensate by exhibiting behavioral thermoregulation. After periods of foraging in hot areas, they retreat to the shade and lie down on the shaded ground to cool off.<ref name= "OShea1991"/><ref name= "hubert"/><ref name= "Martin"/>

==References== {{Reflist}}

==Sources== {{Commons|Xerus rutilus}} * {{MSW3 Sciuridae}}

Category:Xerini Category:Mammals described in 1828 Category:Taxonomy articles created by Polbot Category:Taxa named by Philipp Jakob Cretzschmar