Composition and relative abundance in a temperate zone butterfly fauna

Abstract

THE DONNER PASS AREA, lying, on the crest of the Sierra Nevada range in Placer Country, California, provides a rich variety of habitats lying between 6900 and 8300 feet elevation. During the summers of 1956 and 1960, the authors made an intensive study of this region and we have reported elsewhere (Emmel & Emmel, 1962a, 1962b) on the ecology and factors affecting distribution of the 74 species composing the butterfly fauna. We wish to report here the interesting data obtained on the faunal composition and relative abundance of species within the seven major Rhopalocera groups recorded in the Donner Pass area, and to evaluate the possible factors influencing this distribution of species.