Dependent on the environment and the nature of the animals involved, competition between species may have varying results. In 1934, the Russian ecologist Gause stated what has come to be known as Gause's Principle. This states that no two species can coexist indefinitely on the same limiting resource. That is, if there's not enough of some resource in the environment to sustain both species, then one species ultimately will be excluded from the region.
Although there are many things that can affect this relationship, such
as immigration into the area, we do usually find significant differences between the
ecological niches of closely related species; species that we expect would require
similar resources. Locally, for example, we have two kangaroo rats of similar size:
Merriam's and Ord's kangaroo rats. Both are seed eaters, obtaining their food
in similar ways. The differences, though, include one being comfortable on hard ground
while the other prefers sandy soil. Thus, by spending most of their time on areas
differing in soil types, they are actually avoiding most of the potential
competition.
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.