By Kimberlee Carter
Geographic Range
Xerus erythropus prefer habitats that are fairly dry. Savanas of eastern Sudan and southwestern Kenya, southwestern Morocco, southern Mauritania and Senegal are the native homes of Geoffrey's ground squirrels. (Ellerman, 1940; Hanney, 1975; Happold, 1987; Nowak, 2004)
Habitat
(3280 to 16400 ft; avg. 11480 ft)
Geoffrey’s ground squirrels prefer open “savanna like” habitats. The climate in which they are found is dry. Africa’s open woodlands, grasslands, and rocky country are home to the majority of this species. (Ellerman, 1940; Hanney, 1975; Happold, 1987; Key, 1990)
These animals are found in the following types of habitat:
tropical
; terrestrial
.
Terrestrial Biomes:
desert or dune
; savanna or grassland
; forest
.
Other:
agricultural
.
Physical Description
(10.56 to 33.26 oz)
(7.99 to 18.23 in)
The coarse fur covering its body identifies this species. The fur is frequently tinted the color of the soil in which the animal is found, creating an array of color from brownish to reddish grey to yellowish grey. The pads of the feet lack fur. A few sparse white hairs may occupy the area surrounding the foot. A white, or buff, stripe appears on both sides of the body running from the shoulders to the hind quarters. The total length of the body is between 203 to 463 mm with a tail length of 180 to 274 mm. The tail is somewhat flattened and usually a shade darker than the rest of the body. The ears are small. Claws are present, long and slightly curved, but climbing trees is nearly impossible for Xerus erythropus. (Ellerman, 1940; Hanney, 1975; Nowak, 2004)
Some key physical features:
endothermic
; homoiothermic; bilateral symmetry
.
Sexual dimorphism:
sexes alike.
Reproduction
Female Xerus erthyropus breed once yearly.
Mating occurs throughout the year, but is often coordinated within social groups.
Xerus erythropus live in social colonies. Within these colonies there are several females; males travel between colonies. Chirping and chattering vocalizatins are used by males to attract a mate. Defending mates is unknown in this species; most likely there is no defense of mates due to the fact that males never stay in one social colony for an extended period of time. (Ellerman, 1940; Hanney, 1975; Nowak, 2004)
Mating systems:
polygynous
.
Breeding occurs year round, but is synchronized among the females of one particular social group. Gestation of Xerus erythropus is 64 to 78 days. The average litter number is about three young. Geoffroy’s ground squirrels have a high rate of litter loss with some 70% of all pregnancies failing to produce a litter. It is unknown when weaning occurs, but sexual maturity is attained at about one year. (Ellerman, 1940; Happold, 1987; Nowak, 2004)
Key reproductive features:
iteroparous
; year-round breeding
; gonochoric/gonochoristic/dioecious (sexes separate); sexual
; viviparous
.
Young are cared for by the female. Males do not invest time in parental care because it is uncertain which young are genetically related to them. The females in social groups dig elaborate burrows for raising young. A burrow for young consists of a nesting area with soft, dried grasses and several emergency exits. These burrows are usually deeper than standard burrows. Females protect their burrows aggressively. They provide food for their young and often instruct the young in collecting food and avoiding predators. Time to weaning is unknown, but at about 1 year both male and female young become independent and sexually mature. (Ellerman, 1940; Hanney, 1975; Happold, 1987; Nowak, 2004; Rosevear, 1969)
Parental investment:
precocial
; female parental care
; pre-hatching/birth (protecting: female); pre-weaning/fledging (provisioning: female, protecting: female); pre-independence (provisioning: female, protecting: female); post-independence association with parents; inherits maternal/paternal territory.
Lifespan/Longevity
Longevity of Xerus erythropus is limited by predation. Human disruption of habitats may also limit the lifespan, which averages 2 years in the wild. (Nowak, 2004)
Behavior
Xerus erythropus are very social. No known socail hierarchy exists in this species. The social groups usually consist of groups of 6 to 10 individuals, with a maximum of 30 individuals. The majority of the groups are made up of females. Males only enter social groups when the females are in estrus. When mating is not occurring, males roam from social group to social group.
A typical day in the life of Xerus erythropus consists of making various vocal sounds to communicate and socialize with their neighbors, sunning themselves, and collecting and storing food. Geoffrey’s ground squirrels often sit erect when eating. This allows them to have a greater view of their environment. By sitting erect, the animal is also able to be more alert to sounds that may indicate an approaching predator. The tail of Geoffrey’s ground squirrels is an excellent indicator of their mood. When a squirrel is alert, the tail is held over the back and flicked back and forth with the hairs erect. A frightened squirrel will run with its tail parallel to its body. A state of relaxation is identified by a tail that is so relaxed it is almost dragged along the ground. Xerus erythropus are active during the day. On extremely hot days, this species is active at dawn and dusk to avoid excessive heat during midday. (Ellerman, 1940; Hanney, 1975; Happold, 1987; Nowak, 2004)
Home Range
Xerus erythropus establish colonies that are usually occupied by females. A female’s home range is much smaller than a male's at about 1.37 ha. A male’s home range is more extensive with a measurement of 7.01 ha. Geoffrey’s ground squirrels are territorial, but share their burrows with several other burrowing species. (Dobigny, Gautun, and Nomao, 2000; Ellerman, 1940; Hanney, 1975; Happold, 1987; Nowak, 2004)
Key behaviors:
terricolous; fossorial
; diurnal
; crepuscular
; motile
; aestivation; territorial
; social
; colonial
.
Communication and Perception
Vocalizations are an important form of communication. Squeaking and chirping indicate pleasure, protest and distress. A higher pitched chirping or chattering may suggest threats of higher alarm. Mating males and females communicate with one another through olfaction/phermones as well as vocalizations. Geoffrey’s ground squirrels have facial scent glands with which they mark their territory and their food. (Dobigny, Gautun, and Nomao, 2000; Happold, 1987; Nowak, 2004)
Other communication keywords:
scent marks
.
Food Habits
Xerus erythropus are omnivorous. The diet consists of palm nuts, banana, pawpaw, seeds, pods, grains, yams and other roots, insects, small vertebrates, and bird’s eggs. Foods such as nuts and seeds are often stored around the burrows. (Ellerman, 1940; Hanney, 1975; Happold, 1987; Nowak, 2004; Rosevear, 1969)
Primary Diet:
omnivore
.
Animal Foods:
mammals; amphibians; reptiles; eggs; insects.
Plant Foods:
roots and tubers; seeds, grains, and nuts; fruit.
Foraging Behaviors:
stores or caches food
.
Predation
The defense system of Xerus erythropus lies in their burrow structures. The burrows provide protection from predators when the alarm call has been heard. Geoffrey’s ground squirrels will often cautiously peep out of their burrows to search for the cause behind the alarm call. The main predators of Xerus erythropus are various carnivores such as raptorial birds and mongooses. (Dobigny, Gautun, and Nomao, 2002; Hanney, 1975; Happold, 1987; Nowak, 2004)
Anti-predator adaptations::
cryptic
.
Ecosystem Roles
Several predators of Xerus erythropus also share burrows with this species. Several mongoose species benefit from the burrows that have already been made by Geoffrey’s ground squirrels. In return, the mongooses offer protection from bird of prey and snakes that threaten the colony.
Xerus erythropus disperse seeds by caching their food. Stores are often forgotten and the seeds germinate.
Geoffrey’s ground squirrels serve as a host to ticks. It has also been discovered that Xerus erythropus are susceptible to trypanosomes in the blood and can carry rabies. (Dobigny, Gautun, and Nomao, 2000; Hanney, 1975; Happold, 1987; Key, 1990; Nowak, 2004)
Key ways these animals impact their ecosystem:
disperses seeds; creates habitat.
Economic Importance for Humans: Negative
Farmers often try to protect their crops, such as yams, from Xerus erythropus. Open agricultural fields of roots and tubers are an extensive feeding ground for Geoffrey’s ground squirrels causing them to be classified as pests by farmers. As previously mentioned, Geoffrey's ground squirrels can be infected with trypanosomes and rabies. (Dobigny, Gautun, and Nomao, 2000; Ellerman, 1940; Hanney, 1975; Key, 1990; Logan, Cornet, and Wilson, 1993; Nowak, 2004; Rosevear, 1969)
Ways that these animals might be a problem for humans:
injures humans (causes disease in humans
, carries human disease); crop pest; causes or carries domestic animal disease
.
Economic Importance for Humans: Positive
Geoffrey’s ground squirrels make good pets. They tame readily and are often kept in houses, analogous to house cats in South Africa. In some parts of Africa Xerus erythropus are hunted for their meat. (Ellerman, 1940; Hanney, 1975; Happold, 1987; Nowak, 2004)
Conservation Status
IUCN Red List: [link]:
Least Concern.
US Federal List: [link]:
No special status.
CITES: [link]:
No special status.
No special status was found for Xerus erythropus.
Other Comments
Interest in the coexistence of Xerus erythropus with several mongoose species has lead to numerous studeis. The pairing is unique since the mongoose is also a predator of Geoffrey’s ground squirrels. This coexistence proves that protective habitats are more important than obtaining food. This may be attributed to the fact that mongooses have many sources of food that are abundant enough that they do not need to rely on Xerus erythropus for nourishment. Several studies have been conducted on this bizarre relationship, and many more are in progress. (Dobigny, Gautun, and Nomao, 2000; Dobigny, Gautun, and Nomao, 2002; Logan, Cornet, and Wilson, 1993)
For More Information
Find Xerus erythropus information at
Contributors
Matthew Wund (editor), University of Michigan.
Kimberlee Carter (author), University of Michigan. Phil Myers (editor, instructor), Museum of Zoology, University of Michigan.

