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Desert Diary
Biology/High and Dry


The northern portions of the Chihuahuan Desert seems to discourage a lot of animals that lie to the east and west of it. Such animals as the Northern Pygmy Mouse and the Collared Peccary occur to the east and then swing south well into Mexico, only to re-emerge back into the United States in southwestern New Mexico and in Arizona.

At first glance, the desert climate would seem to be the culprit. However, back in the ice age, we find the same pattern in some animals. The raccoon, for example, occurs as a fossil in the Hill Country of Texas and in California, but seems absent until historic time in our area. Likewise, the Sabertooth Cat reached the eastern fringes of what now is the Chihuahuan Desert in New Mexico, but isn't apparent again until west of our region. It's possible, of course, that different climatic conditions cause similar patterns. The Chihuahuan Desert is high country expected to be colder than areas to the east and west during the ice age, and currently is high and dry. Explanation? Maybe!
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Contributor: Arthur H. Harris, Laboratory for Environmental Biology, Centennial Museum, University of Texas at El Paso.

Desert Diary is a joint production of the Centennial Museum and KTEP National Public Radio at the University of Texas at El Paso.

Geographic range of peccary

Geographic range of the Collared Peccary.