A New Subspecies of Wood Rat (Neotoma mexicana) from Colorado

In the rugged canyons and foothills south of the Arkansas River, researchers have uncovered a previously unrecognized variety of the Mexican wood rat. This population, concentrated around Two Buttes and the town of Higbee, stands apart from its close relatives through subtle but consistent differences in skull shape and overall size. The finding adds a new thread to the tapestry of North American rodent diversity and highlights how isolated habitats can nurture distinct lineages.

The newly described form, provisionally called Neotoma mexicana scopulorum, is larger than typical members of the species and bears a uniquely arched skull with broad zygomatic arches and a wide rostrum. Its fur presents a muted gray‑buff tone overlaid with darker black patches, while the tail shows a striking bicolor pattern of dark top and lighter underside. Detailed measurements of the cranium—such as a mid‑frontal constriction and concave supra‑orbital ridges—provide the diagnostic clues that set this subspecies apart.