Most animals and plants live preferentially in one kind of habitat. We expect to see Texas Antelope Squirrels in mountains where there are exposed rocks; Muskrats in streams, ponds, and drainage ditches; and tree squirrels in, of all places, trees! Everything nice and neat. Except sometimes, things don't quite work out the way we expect.
Our Cactus Mouse is well known for its adherence to the rocky lower
slopes of our Chihuahuan Desert mountain ranges; so much so, that we can predict their
presence with considerable certitude. Strangely enough, though, there's another
habitat also preferred—and it couldn't be much more different from the first and
still be in the desert. Its alternative place of business is a well developed sand
dune, preferably formed around the bases of low shrubs. The spaces between rocky
hillside and sandy dune? Devoid of Cactus Mice as near as we can tell. The question,
then, is what is the common element that makes these two very different habitats so
desirable. You don't know? Well, don't fret, because neither do the
biologists.
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.