Lounge-lizard or effec­tive adap­ta­tion to the desert heat?

Have you ever been to Anza Bor­rego State Park and seen a cute chip­munk-like ani­mal run­ning in the sand, or seen 3” holes in the ground and won­dered what made them? Most like­ly it is the White-tailed Ante­lope Squir­rel, one of the many ani­mals that makes the desert its home and is well adapt­ed to sur­vive and thrive there.

Back­ground:  Ammo­sper­mophilus leu­cu­rus is about 6” long, weighs 5–6 ounces, and has a white stripe on each side.  It has a 3″ long tail that is white on its under­side. It is diur­nal, so dur­ing the spring and sum­mer it is the only small desert mam­mal you are like­ly to see dur­ing the day. It is remark­ably adapt­ed to with­stand the hot desert heat and is report­ed to sur­vive body tem­per­a­tures up to 108 F. To cool down, it will lay down flat on the ground, par­tic­u­lar­ly after remov­ing the top­most lay­er of soil with its feet.

Ready for action!

The squir­rels are omniv­o­rous, eat­ing seeds, leaves, insects, arthro­pods and fruit, and store their food in their under­ground bur­rows. It is esti­mat­ed that they for­age over a range of about 15 acres. They are active all year in Anza Bor­rego. The females have a lit­ter in spring and some­times in sum­mer; the lit­ter size usu­al­ly ranges from 5–14 babies, and the young are reared entire­ly by the female. They are found in south­west­ern deserts west and north of the Col­orado river.

How to See Them: Some of the best places to see them are where humans reg­u­lar­ly vis­it, such as the vis­i­tor cen­ter. I’ve seen them there many times, but they usu­al­ly run if you approach them. As with most wildlife, you have a bet­ter chance of observ­ing them if you sit qui­et­ly near where you have seen them. While some of the squir­rels have been giv­en treats by well-mean­ing peo­ple, please don’t feed them. For more infor­ma­tion about the Ante­lope Squir­rel, vis­it: http://digital-desert.com/wildlife/antelope-squirrel.html.

Pho­tos and blog by Bar­bara Swanson

On any pic­nic Sun­day, the Anza-Bor­rego State Park Vis­i­tors Cen­ter has more than its share of local entertainment.