The Mohave ground squirrel (Xerospermophilus mohavensis ) is a species of ground squirrel found only in the Mojave Desert in California. The squirrel was first described in 1886 by Frank Stephens of San Diego. It is listed as a threatened species under the California Endangered Species Act, but not under the federal Endangered Species Act. The IUCN lists this species as near threatened.
The Mohave ground squirrel lives in the California desert and is amongst its more elusive inhabitants. They have highly developed survival skills for the desert which enable them to avoid this hostile climate’s extremes. Mohave ground squirrels are cryptically colored to match their sandy environment. It is very hard to find them and to observe and study them is even more difficult.
The Mohave ground squirrel is a native of California’s northwest Mohave Desert. It inhabits open areas, like deserts, where there are many herbaceous, shrubby plants in sandy or gravelly soil, where they make their burrows.
Mohave ground squirrels are diurnal and solitary animals. When they emerge in the morning, they like in the sun to bask, periodically rotating their bodies to warm the different parts. They eat continuously during daylight hours, starting three hours after sunrise and going to one hour before sunset. If threatened, the squirrel will run, typically carrying its tail over its back. However, they rarely run for long distances, as they usually are close to their burrows. Their camouflage colors enable them, instead of fleeing, to stay still and blend into the environment. If disturbed when feeding, they stand up on their hind legs so they can survey the area better. Mohave ground squirrels typically enter dormancy between July and September until February, having built up their fat reserves, at a time when temperatures drop to 20 to 30 degrees Celsius and food sources decrease due to shortage of water.
The omnivorous Mohave ground squirrel mostly eats seeds, fungi, forbs and fruits; sometimes they eat caterpillars.
Mohave ground squirrels are polygynous. The males emerge from dormancy up to two weeks before the females and may lay claim to and defend a territory in their attempt to mate with a number of females. The mating season is during February and March. Gestation lasts about one month and births are generally in late March or the beginning of April. Litters may number 4 to 9 babies. Kittens are usually blind when born and are also unable to hear, and they have hair only on their heads. They are usually weaned at around 32 days. Females are sexually mature at 1 year old (if conditions allow), and males usually not until two years of age.
The Mohave ground squirrel is under threat by loss and degradation of its habitat as a result of urban and suburban development, also rural development, agriculture, livestock grazing, military activities, energy development and off-highway vehicles. Climate change will make the Mohave Desert even hotter and drier, and this could be another threat. For example, the Joshua tree, the seeds of which form a significant part of this squirrels’ diet, may move its range as a response to climate change.
According to the IUCN Red List, the total Mohave ground squirrel adult population size is unknown but may exceed 100,000 individuals. Currently this species is classified as Near Threatened (NT) and its numbers today are decreasing.
Not much information is available about the ecosystem services provided by Mohave ground squirrels. They may provide seed dispersal, specifically for Joshua trees. The burrows constructed by they may contribute to soil aeration, based on similar practices by round-tailed ground squirrels.