When a small striped beggar approached our naturalist group at Red Rock Canyon (Nevada), several in our group proclaimed it to be some sort of Chipmunk. It was, after all, a rodent marked with those familiar backstripes and fully equipped with “feed me” eyes. We were just sitting down for a brown bag lunch in the middle of a gravelly Joshua Tree desertscape, however. Though there are Chipmunks in Nevada and the far western states they are, like their eastern cousins, primarily creatures of woodland areas – inhabiting mostly higher elevation pinyon pine and juniper scrub. A majority of the naturalists in attendance were of eastern stock and could be forgiven the error. We are a specialist group, you see.
I immediately declared the thing to be a ground squirrel but, unfortunately, given my own eastern bent, was unable to say what kind. It took a sneak visit to the visitor center gift shop and a peak in their copy of the Audubon Field Guide to the Southwestern States to confirm that our visitor was a fine example of an Antelope Ground Squirrel. To be specific, it was a White-tailed Antelope Ground Squirrel. Equipped with my new, and now accurate information, I returned to pronounce my up-dated judgement but the group had already boarded the bus. They were waiting for me. (I did end up buying that Audubon Guide, which is what took me so long, and no, the bus group was not waiting for anything I had to say).
As long as you, dear reader, don’t have a bus to catch allow me to explain a few facts. Perhaps the best way to identify a ground squirrel on sight is to look at those shriveled little ears. These appendages are cropped off very close to the head and look as though they were clipped. The Thirteen-lined Ground Squirrel is an eastern member of this group which shares this somewhat earless trait. In this case, as a white-tailed member of the Antelope Squirrel Club, the two dark-bordered side stripes and the white-bottomed tail are very distinctive (see detail shot here). The species often runs with the tail held so tightly up against the back that it appears to be an additional white body stripe (see below). Chipmunks run with their tails straight up and have large ears and, like I said, don’t live in the desert.
Our beggar never made it close enough to actually accept any offerings. It had chosen the wrong group from which to beg (naturalists…hmm, hmm… do not throw food at animals – at least not when in the company of other naturalists. We spend far too much time telling other people not to do this). I offered it an imaginary treat in order to lure it closer but the ruse was short-lived and this creature soon turned “tail” and ran to the shelter of a creosote bush. Antelope squirrels are not dumb. Do not try this with raccoons, by the way, because they get angry when fooled.
Ground Squirrels are one of the only small desert mammals who are active at mid-day. This being mid-November, the spritely little fellow was certainly in no danger of drying out in the sunlight but earlier in the summer it would have been subject to very hot dry conditions. Fortunately, they are perfectly adapted, both physically and behaviorally, for life in arid climates. To start with, they can get all their moisture from their food which includes an eclectic mix of foliage, seeds, insects, and even a lizard or two. They are omnivorous and not strictly “seed lovers”, as their Latin genus name Ammospermophilis implies. They avoid Hyperthermia, the state of over-heating, by retreating into the shelter of their shaded burrows or climbing into the low shrubbery to take advantage of the cooling air flow. Should their body temperatures rise above normal, they can tolerate internal temperatures of 104 degree F. without dropping dead or requiring basting.
There were dozens of burrows about the site where we saw the ground squirrel in question and all were located near the shaded base of the local cacti, Joshua Trees or saltbrush. It has been well documented that over-heated Antelope Ground Squirrels will deliberately press their scantily haired bellies against the cool sand at the entrance of their holes in order to transfer heat and cool off. They maintain an abundance of burrows throughout their range so that relief is always near.
Of course, those burrows also represent sanctuary from a whole host of predators as well. Small juicy mammals are prime food for hawks, owls, coyotes, and fox. Our little squirrel was protected from depredations by the presence of people and was able to operate in full view without fear. Not too far away and along one of the trails leading from the visitor center I came upon some well-dried coyote scat. The sun-hardened relict contained numerous bones – many of which looked to be those of a desert cottontail or jack rabbit – but one set of small gleaming incisors were obviously Chipmunk sized (see below and detail here). I put the poo back down without probing the mass, but I’d be willing to bet those teeth belonged to a White-tailed Antelope Ground Squirrel whose desert luck had run out.