Fewer mammalian species occurred on summits of sheer-walled buttes
than occurred in similar "mainland" control sites, but
density of small mammals on buttes equaled or exceeded mainland
density. Peromyscus crinitus, the only terrestrial mammal on Jug
Butte, occupied a larger habitat niche there than in control areas. No
such niche expansion was noted for P. crinitus on Junction Butte,
where four other species of small mammals (Eutamias quadrivittatus,
Neotoma lepida, Neotoma cinerea, Peromyscus truei) and at least one
large mammal (Canis latrans) also occurred. At least 18 species of
terrestrial mammals inhabit the control sites. It is hypothesized that
the species number remains static on each butte and is a function of
the unique dispersal abilities of each species and does not represent
an equilibrium between recurrent colonization and extinction.
Published in Southwestern Naturalist, volume 26, issue 4, on pages 395
- 407, in 1981.
