Antelope Ground Squirrel

Antelope ground squirrels (Ammospermophilus leucurus) are hyperactive. They never stop moving! While exploring Grimes Point Archeological Site along Nevada Highway 50 east of Fallon NV, Leonard and I came upon this cute little guy (gal?). We sat down and it scurried around us for a long time, never stopping. I could not focus my camera, so just began snapping pictures in the hope that if I took enough pictures a few would be acceptable. Hooray for digital cameras and the “delete” function.

Antelope ground squirrels are greyish brown on the back with a white stripe running from its shoulder to hind end on each side. There are no dark stripes on the body. The undertail is white. The tail is usually held closely over the this ground squirrel’s back while running, exposing the white side. There is a subterminal black band on the tail. The ventral surface of the body is whitish, the outer surface of the legs are somewhat reddish and the ears are small and rounded.

This native does not hibernate and remains active throughout the year. Being diurnal it also is active throughout the day and night. All nine subspecies of antelope ground squirrel live in arid, hot regions of Southwestern United States, the Baja Peninsula and Northwestern Mexico. It prefers mostly rocky, sandy or gravelly soil where it can burrow.

Antelope ground squirrels are omnivorous. Foliage is their primary food, but they also eat seeds, nuts, fruits, arthropods and small vertebrates (lizards and small rodents). Cheek pouches are used to transport seeds, nuts and small fruits to surface caches.

Most antelope ground squirrel reproductive activity occurs in the early spring with generally one litter per year. They dig their own burrows or use the abandoned burrows of other rodents. The gestation period is 30 to 35 days and the pups are weaned at about 65 days. Litters usually average 8 young but vary from 5 to 14 with northern population litters  generally being larger. Antelope ground squirrels can reproduce at about a year of age.

Living in hot, arid deserts, antelope ground squirrels must deal with intense heat, low humidity, limited water and often insufficient food. When the outside temperature is too cold, a mammal must maintain its temperature by increasing metabolic activity. If conditions are too hot, the mammal has to cool itself by panting, sweating or other means. An antelope ground squirrel holds its tail close to its back so the white undersurface reflects light, helping to keep it cooler. Additionally, this little rodent has a nearly constant metabolic rate between 90° and 107° F ambient temperature (thermal neutral zone) and shows no discomfort even when its body temperature reaches 110°F.  As a last resort if temperatures become too extreme, it will wash its entire head with drool from its mouth, cooling by evaporation. By having a thermal neutral zone higher than any non-sweating animal and the ability to cool by salivation, this little rodent can survive in some of the hottest and driest regions on earth and be active during the day.  When it is too hot antelope ground squirrels go into underground burrows where conduction, convention and radiation cool their bodies.

Additionally, antelope ground squirrels have kidneys that are adapted to drink highly mineralized desert water with minimal loss of water while eliminating nitrogenous and other wastes in the urine.

Unfortunately antelope ground squirrels carry fleas that can harbor sylvatic (occur in, affecting or transmitted by wild animals) plagues that can then be contracted by man.

This little whirlwind was certainly fun to watch.


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