Lepidoptera of North America 9. Butterfly distribution and dispersion across the Montane Islands and drainages of the Chihuahuan Desert

Abstract

This paper tabulates the butterfly fauna of 36 montane and five canyon land refugia in the Chihuahuan desert, primarily in New Mexico and Trans-Pecos Texas, but to some extent also in Ariwna, Colorado, Sonora, Chihuahua, and Coahuila. Theories for butterfly dispersal between ranges are evaluated by examining the fauna correlation between refugia Refuge diversity is highest in the Gila Mts. complex (ca. 175 sp.) and lowest in the canyon lands of northeastern New Mexico (ca. 70 sp.). As a general rule, population diversity decreases as one retreats farther from the main backbone of the Rocky Mts. to the north or from the main branches of the Sierra Madre to the south. The 41 refugia are divided into eight groups, each consisting of three to eight members. About 27 additional refugia are not discussed, either because data is lacking (eight cases) or because the computer analysis began to become unstable, and the sheer data volume unmanageable.