Status of Myotis lucifugus phasma and Comments on Variation in Myotis yumanensis

Abstract

Preliminary studies of bats of the species Myotis yumanensis and M. lucifugus in New Mexico, Arizona, Utah and Colorado, indicate that the subspecies phasma, described by Miller and Allen as a race of M. lucifugus, may instead be referrable to the species M. yumanensis. Californian examples of phasma seem referrable to the species M. lucifugus, but may show evidence of introgression with M. yumanensis. New Mexico and east-central Arizona are occupied by a popula- tion of M. yumanensis which is darker in color than populations of this species in the remainder of Arizona and in Utah and Colorado. Efforts to identify two myotis collected at Allison, La Plata Co., Colorado, soon revealed the existence of considerable confusion in the literature regard- ing Myotis yumanensis yumanensis (H. Allen) and Myotis lucifugus phasma Miller and Allen. For example, Miller and Allen (1928) state that M. yuma- nensis is unknown in Colorado-but then list a specimen for that state. A more recent work (Hall and Kelson, 1959) maps the range of M. 1. phasma in such a manner as to exclude the type locality of the subspecies. We found our speci- mens were not assignable with certainty to either species on the basis of pub- lished descriptions. We wish to thank the Laboratory of Anthropology of the Museum of New Mexico, who supported the field work, and, for their generosity in lending