The unstriped ground squirrel (''Xerus rutilus'') is a species of

rodent Rodents (from Latin , 'to gnaw') are mammals of the order Rodentia (), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are n ...

(order Rodentia) in the family

Sciuridae Squirrels are members of the family Sciuridae, a family that includes small or medium-size rodents. The squirrel family includes tree squirrels, ground squirrels (including chipmunks and prairie dogs, among others), and flying squirrels. Squ ...

. It is the only member of the genus ''Xerus'' . It is found in

Djibouti Djibouti, ar, جيبوتي ', french: link=no, Djibouti, so, Jabuuti officially the Republic of Djibouti, is a country in the Horn of Africa, bordered by Somalia to the south, Ethiopia to the southwest, Eritrea in the north, and the Red ...

, Eritrea,

Ethiopia Ethiopia, , om, Itiyoophiyaa, so, Itoobiya, ti, ኢትዮጵያ, Ítiyop'iya, aa, Itiyoppiya officially the Federal Democratic Republic of Ethiopia, is a landlocked country in the Horn of Africa. It shares borders with Eritrea to the ...

Kenya ) , national_anthem = " Ee Mungu Nguvu Yetu"() , image_map = , map_caption = , image_map2 = , capital = Nairobi , coordinates = , largest_city = Nairobi ...

Somalia Somalia, , Osmanya script: 𐒈𐒝𐒑𐒛𐒐𐒘𐒕𐒖; ar, الصومال, aṣ-Ṣūmāl officially the Federal Republic of SomaliaThe ''Federal Republic of Somalia'' is the country's name per Article 1 of thProvisional Constituti ...

, Sudan,

Tanzania Tanzania (; ), officially the United Republic of Tanzania ( sw, Jamhuri ya Muungano wa Tanzania), is a country in East Africa within the African Great Lakes region. It borders Uganda to the north; Kenya to the northeast; Comoro Islands ...

, and

Uganda }), is a landlocked country in East Africa. The country is bordered to the east by Kenya, to the north by South Sudan, to the west by the Democratic Republic of the Congo, to the south-west by Rwanda, and to the south by Tanzania. The sou ...

. Its natural

habitat In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...

s are dry

savanna A savanna or savannah is a mixed woodland- grassland (i.e. grassy woodland) ecosystem characterised by the trees being sufficiently widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground to ...

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 Dorsal (from Latin ''dorsum'' ‘back’) may refer to: * Dorsal (anatomy), an anatomical term of location referring to the back or upper side of an organism or parts of an organism * Dorsal, positioned on top of an aircraft's fuselage * Dorsal c ...

-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 long with an average tail length of . This tail is flat in appearance. Body weight varies across studies and habitats and ranges from . 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. ''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 The Barbary ground squirrel (''Atlantoxerus getulus'') is a species of rodent in the family Sciuridae. It is monotypic within the genus ''Atlantoxerus''. It is endemic to the Atlas mountains in Morocco and some parts in Algeria, and has been ...

Vibrissae Vibrissae (; singular: vibrissa; ), more generally called Whiskers, are a type of stiff, functional hair used by mammals to sense their environment. These hairs are finely specialised for this purpose, whereas other types of hair are coarser ...

(whiskers) length and brain size are both smaller than arboreal

squirrels Squirrels are members of the family Sciuridae, a family that includes small or medium-size rodents. The squirrel family includes tree squirrels, ground squirrels (including chipmunks and prairie dogs, among others), and flying squirrels. Squ ...

of the region, but are similar to other

terrestrial Terrestrial refers to things related to land or the planet Earth. Terrestrial may also refer to: * Terrestrial animal, an animal that lives on land opposed to living in water, or sometimes an animal that lives on or near the ground, as opposed to ...

squirrels. No significant

sexual dimorphism Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most an ...

is noted in ''X. rutilus''.

Local and indigenous names

Tigrinya language (; also spelled Tigrigna) is an Ethio-Semitic language commonly spoken Eritrea and in northern Ethiopia's Tigray Region by the Tigrinya and Tigrayan peoples. It is also spoken by the global diaspora of these regions. History and literature ...

: or (mitsutsilay, chechera). In Somali Dabagaale

Ecology

Range and habitat

The unstriped ground squirrel is endemic to Ethiopia, Kenya, Somalia, Sudan, Tanzania, Djibouti, Eritrea and Uganda and probably extant in Somalia. Its natural habitats include dry (arid) savanna and subtropical or tropical dry shrubland. Populations occupy many overlapping regions with its sister group, the striped ground squirrel (''X. erythropus''), in northeastern Africa. ''X. rutilus'' dig and occupy burrows in generally arid conditions.

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. 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 Forage is a plant material (mainly plant leaves and stems) eaten by grazing livestock. Historically, the term ''forage'' has meant only plants eaten by the animals directly as pasture, crop residue, or immature cereal crops, but it is also used ...

for food. This ability is not diminished across a variety of different environments, including those with a poor to moderate food supply.Ecological factors affecting the foraging behaviour of Xerus rutilus. (2010). African Zoology, 45(2), 265–272.

Behavior

Burrows

''X. rutilus'' are mainly

solitary Solitary is the state of being alone or in solitude. The term may refer to: * shortened form of solitary confinement * Solitary animal, an animal that does not live with others in its species * Solitary but social, a type of social organization ...

. 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 ('' X. erythropus''). 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 Sedentary lifestyle is a lifestyle type, in which one is physically inactive and does little or no physical movement and or exercise. A person living a sedentary lifestyle is often sitting or lying down while engaged in an activity like soci ...

Dominance hierarchy

Although not

territorial A territory is an area of land, sea, or space, particularly belonging or connected to a country, person, or animal. In international politics, a territory is usually either the total area from which a state may extract power resources or a ...

, a

dominance hierarchy In biology, a dominance hierarchy (formerly and colloquially called a pecking order) is a type of social hierarchy that arises when members of animal social groups interact, creating a ranking system. A dominant higher-ranking individual is so ...

exists with male squirrels being dominant over females and younger squirrels. ''X. rutilus'' demonstrate dominance via vocalization, tail displays, and physical lunges.

Physiology

Thermoregulation

Unstriped ground squirrels generally reside in hot

arid A region is arid when it severely lacks available water, to the extent of hindering or preventing the growth and development of plant and animal life. Regions with arid climates tend to lack vegetation and are called xeric or desertic. Most ...

conditions and compensate by exhibiting behavioral

thermoregulation Thermoregulation is the ability of an organism to keep its body temperature within certain boundaries, even when the surrounding temperature is very different. A thermoconforming organism, by contrast, simply adopts the surrounding temperature ...

. After periods of foraging in hot areas, they retreat to the shade and lie down on the shaded ground to cool off.

References

Sources

* Thorington, R. W. Jr. and R. S. Hoffman. 2005. Family Sciuridae. pp. 754–818 ''in'' ''Mammal Species of the World a Taxonomic and Geographic Reference''. D. E. Wilson and D. M. Reeder eds. Johns Hopkins University Press, Baltimore. {{Taxonbar, from=Q1763595, from2=Q284816 Xerini Mammals described in 1828 Taxonomy articles created by Polbot Taxa named by Philipp Jakob Cretzschmar