The systematics of the Neotropical bats of the genue Myotis

Although at least 40 names have been proposed for Neotropical bats of the genus Myotis, only seven species are now recognized. The limits imposed by the diagnoses of these seven species do not include all the actual interspecific variation observed. Therefore, many specimens of doubtful allocation have been misidentified, usually as Myotis nigricans. Fourteen species of Neotropical Myotis are recognized herein. These include two new species: M. martiniquensis from the island of Martinique, and M. larensis from northern Venezuela. Among the remaining 12, eight are considered monotypic: M. elegans, restricted to the tropical lowlands of North America; M. dominicensis, the island of Dominica; M. atacamensis, coastal desert of northern Chile and Peru; M. albescens, widespread in the low lands of the Neotropics; M. simus, restricted to the Amazon Basin; M. riparius, Honduras south to Uruguay in the low lands; M. chiloensis, central and southern Chile; M. ruber, southern Brazil and Paraguay. The other four are considered polytypic: M. nigricans is widespread in the tropical lowlands of Mexico, and is found at both low and high elevations from Chiapas to Paraguay, with four subspecies; M. keaysi, with two subspecies, occurs in the tropical lowlands and adjacent mountain slopes of Mexico, and in the mountains from Chiapas to southern Peru; M. levis, divided into two subspecies, is restricted to southern (mainly temperate) South America east of the Andes; M. oxyotus, also with two subspecies, occurs only in the Andes and the highlands of Costa Rica and Panama. Geographic and altitudinal variation are analyzed in those species where appropriate. The disjunct variational patterns of M. keaysi, M. albescens, and M. levis suggest that the collection of a sufficient amount of additional specimen material may necessitate the recognition of additional taxa at some future date