It's long been recognized that competition for resources between species tends to result in natural selection reducing the competition. One way of accomplishing this is to specialize for utilizing that part of the environment where a species holds the competitive edge while abandoning those parts of the ecological space where it's inefficient. The result, over time, ends up in an ecological habitat becoming divided up among the different species, each doing what it does best. This is especially evident in animals easy to observe, such as birds. In forested areas, we often find species of birds that make their living by gleaning insects and insect eggs from trees. Some specialize in working the tree tops, others lower in the canopy, and so on—allowing several species with similar food requirements to coexist.
But what about our Chihuahuan Desert birds, where there are no forests
to be divided up into vertical layers? Shouldn't the desert avifauna be small and
monotonous? Not hardly! The very ruggedness of the desert landscape provides abundant
microhabitats to support our diverse and exciting bird life.
Listen to the Audio (mp3 format) as recorded by KTEP, Public Radio for the Southwest.
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.