Geographic variation in red-backed mice (genus Clethrionomys) of the southern Rocky Mountain region

Listeners are taken on a meticulous field‑based exploration of the red‑backed mouse across the southern Rocky Mountains. The authors describe how they gathered over 160 specimens from diverse locales—Wyoming’s Medicine Bow range, the Big Horn foothills, and the Tetons—charting subtle shifts in fur coloration, stripe patterns, and ear markings. Their observations reveal three broad zones of variation, each with its own distinct palette of greys, reds, and chestnut tones.

Beyond cataloguing these patterns, the study tackles the taxonomic puzzle of whether the northern populations represent a previously unnamed subspecies. Detailed maps and a single illustrative figure guide the listener through the terrain, while comparative notes on related forms clarify long‑standing classification questions. By the end of the first act, the groundwork is laid for a richer understanding of how geography shapes the evolution of these modest yet ecologically important rodents.