Centennial Museum gecko logo

Desert Diary
Mammals/Predator Numbers


Predators number less than their prey since every predator on average consumes many prey animals during its lifetime. Indeed, the most foolish thing a predator can do is to kill the goose that lays the golden egg by harvesting more of their prey than are reproduced. This limitation on the numbers of a predator doesn't, however, act the same way on the number of KINDS of predators. That number depends in part on competition between predators. Competition is interesting because it harms all those who compete with each other. As a result, natural selection tends to reduce competition.

Individuals proficient in taking prey less utilized by competitors tend to survive more—and pass on their genes—than individuals meeting competition head on. The long-term result tends to be dividing up the prey pool, often by specializing on different sized prey or by hunting in different habitats. Thus wolves tend to concentrate on large, hoofed animals; coyotes on rabbits and large rodents; Southwestern gray foxes on small rodents in rugged terrain; and kit foxes on small rodents in the desert basins.
pen and ink

Listen to the Audio (mp3 format) as recorded by KTEP, Public Radio for the Southwest. rule

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.

Rose Creek Wolf Pack

Rose Creek wolf pack, Yellowstone. Photograph courtesy of the National Park Service.