Great Basin Naturalist


A field survey in caves near Grants, New Mexico, and Flagstaff, Arizona, found only an exceptionally poor fauna of 14 species with no strong patterns of cave restriction. The faunal poverty is judged to be correlated with and influenced by the similarly impoverished boreal forests in nearby mountains. Species of flightless arthropods, suitable for cave colonization and restricted to cool-moist litter of boreal (Hudsonian-Canadian Life Zone) forests, are apparently not now present in suitable, nearby mountain habitats. They may not have dispersed to all available montane sites from the Southern Rocky Mountains during glacial conditions. Either the forests did not exist as continuous dispersal corridors for the litter arthropods, or the fauna could not track the rate of spread of the forests.