Cape Ground Squirrel, Xerus inauris
The Cape ground squirrel (Xerus inauris) is native to southern areas of Africa. Its range includes South Africa, Botswana, and Namibia, although it does not occur in coastal areas of this region. In Botswana, it occurs in southwestern Kalahari, and in South Africa, it occurs in south and south central areas. The name of the Cape ground squirrel is misleading, as its range is much larger than the name suggests. It is thought that the name was used in order to distinguish the species from the Eastern Grey Squirrel, brought from Europe to Cape Town by Cecil John Rhodes.
The Cape ground squirrel can reach an average weight of 1.43 pounds, and can have a body length of up to 1.5 feet, with females reaching a slightly smaller size than males. This squirrel has black skin with a short, coarse coat. The fur is red on the back, and the face, belly, sides of the neck, and the frontal areas of the limbs are white. On each side of the body, there is a white stripe of fur that extends from the shoulders to the thighs. The flat tail is colored reddish brown, like rest of the body, with two black bands at the tip. The testes of the male Cape ground squirrels are notably larger than other squirrel species.
The Cape ground squirrel prefers a habitat within arid portions of its range, and will make its home in grasslands, velds, and even along floodplains or agricultural areas. These squirrels form small groups and will dig burrows that take up a space of 7,500 square feet. These burrows can have between 2 to 100 entrances. They help protect the squirrels from predators and extreme heat, although the squirrels spend most of their day outside of them, foraging for food. They do not typically require a water source as most of their hydration comes from their food. The burrows are often shared with yellow mongooses and meerkats.
Each group of Cape ground squirrels can contain up to three adult females, as well as nine sub-adults of mixed sex and young. If a group contains more than three adult females, it will split into smaller groups. Males and females do not live together, and a male group can hold up to nineteen individuals, although typically this number varies. The home range of a female group can reach up to 9.9 acres, with a core area of approximately .62 acres. These ranges sometimes overlap, but the smaller core area is most typically defended against intruders. There is no hierarchy with female groups.
Male groupings of Cape ground squirrels will inhabit a home range of up to thirty acres, and this range surrounds many female groups. Unlike female groups, male groups are managed by age-based hierarchies, and if a fight occurs, the males will use leaping displays to settle the dispute that rarely ends with injuries. Male groups are not territorial and are lenient in foreign squirrels joining.
Cape ground squirrels are capable of mating throughout the year, but mating typically occurs during the arid winter months. A male will approach a female within his larger home territory and chase her in order to mate. The males that are higher up in the hierarchy get “first pick” of mating partners. Both females and males will mate with many individuals. Because of this, it is thought that the larger testes of the male are used for sperm competition, a process by which sperm fight to fertilize an egg, providing offspring that are more viable.
Each litter of Cape ground squirrels can contain up to three pups, which are born hairless and blind in an isolated area of the burrow. The pups are able to see after 35 days, although they remain in isolation for up to 45 days. The pups are weaned at around 52 days of age, when the mother stops lactating and returns to the group. Males will reach sexual maturity at eight months of age, and will leave their birth group at this time, whereas females are sexually mature at ten months of age and will remain in their birth group.
The Cape ground squirrel can make a number of calls, including aggression calls, alarm calls, and play vocalizations. When threatened, this squirrel will emit either a “bi-jo” call for serious threats or a “bi-joo” call for minor threats. When fighting, the Cape ground squirrel will emit a deep growl. Young ground squirrels will emit chirps, squeaks, and play calls. Predators of the Cape round squirrel include snakes, monitor lizards, and jackals. When fending off a threat such as snakes, a group of squirrels will mob up against the threat, stick their bushy tails straight up and lunge at the predator. This is typically a successful method of defense.
The Cape ground squirrel is not in any danger of extinction, although it some areas of it range, it is considered a pest. Farmers have taken to poisoning the grass around the squirrels in order to stop the crop damage and spread of rabies associated with them. Fortunately, the squirrels inhabit protected areas including Kgalagadi Transfrontier Park in Botswana. The Cape ground squirrel has been given a conservation status of “Least Concern” on the IUCN Red List.
Image Caption: Cape Ground Squirrels close to Solitaire in the Namib desert, Namibia. Credit: Hans Hillewaert/Wikipedia(CC BY-SA 3.0)