Abstract:
Morphological and distributional evidence is presented to document the specific stature of Oligoryzomys vegetus (Bangs, 1902) and to clarify its identification with respect to Central American populations of O. fulvescens. The geographic range of O. vegetus covers not only the mountains of western Panama but also the cordilleras de Tilaran, Central, and Talamanca of Costa Pica, generally above 1000 meters elevation and within lower montane and montane biotic zones. Within southern Central America, populations of O. fulvescens usually occur from sea level to 1000 meters in wet tropical and subtropical associations, but numerous instances of sympatry with O. vegetus are recorded in the 1000-1500 meter zone. Two species-group taxa, both described from Costa Pica, are allocated to subjective junior synonymy under O. vegetus, namely Oryzomys fulvescens creper Goodwin, 1945 and Oryzomys fulvescens reventazoni Goodwin, 1945. With improved understanding of its taxonomy and geographic range, Oligoryzomys vegetus emerges as another species of small terrestrial mammal restricted to the highlands of Costa Rica and western Panama, a region which has formed a modest center for mammalian endemism in southern Central America.
