Sometimes our size and culture works against our understanding of the natural world. We complain when the temperature goes above 100 degrees, little thinking of low-lying plants that may be enduring ground-level temperatures of over 140 degrees. Or entering our sheltering houses, so obviously artifacts of our culture, we may forget that for millions of years other organisms have both constructed living areas and turned natural shelters to their use.
One intriguing natural shelter widespread in our desert is formed by lava beds, with their deep fissures and jumbled piles of fallen blocks. Entering into such a lava bed in the heat of summer feels akin to approaching a blast furnace as the radiated heat assaults you from all directions. But in the interstices of fallen rock and shaded fissure, the oven is left behind, and at depth one may even find traces of winter-cooled air, sunk by its greater weight into the nether regions.
In this microhabitat, we sometimes find animals,
such as Mexican Packrats, thriving at elevations well below their
normal haunts of wooded highlands.
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.