Natural History and Karyology of the Yucatán Vesper Mouse, Otonyctomys hatti

Hugh H. Genoways, University of Nebraska - Lincoln
Robert M. Timm, University of Kansas Main Campus
Mark D. Engstrom, Royal Ontario Museum

Copyright 2005, Instituto de BiologÍa, UNAM; Instituto de EcologÍa, UNAM; CONABIO. Mexico, 2005. Used by permission.

Abstract

Seventeen specimens of the rare Yucatán vesper mouse, Otonyctomys hatti, are now known from Belize, Guatemala, and the Mexican states of Campeche, Quintana Roo, and Yucatán. We herein report a second specimen of O. hatti, from Belize, extending the known geographic range of the species 95 km to the southeast in the country. This is the first location at which O. hatti has been taken sympatrically with the Central American vesper mouse, Nyctomys sumichrasti. We also report data on three additional specimens of O. hatti from Campeche. Nyctomys and Otonyctomys share similar habits and habitat requirements, and might compete where they overlap. However, the distribution of O. hatti corresponds closely to that of other Yucatán endemic, and the distinct distributions of the two genera probably reflects biogeographic history and different habitat requirements, rather than result from direct competition. The karyotype of O. hatti is 2n=50, F=58. Although superficially similar, it differs in important respects with the karyotypes reported for N. sumichrasti.