Geographic Variation in the Pocket Gopher, Cratogeomys castanops, in Coahuila, México

This study offers a thorough look at the plateau pocket gopher, a modest but widespread rodent that inhabits the varied landscapes of northern Mexico. Drawing on more than two hundred specimens collected from dozens of sites, the authors map where the animal lives—from low‑lying river valleys to the high plateaus of the Sierra Madre Oriental—while describing the soils and vegetation that make each locale suitable.

The researchers uncover four previously unknown subspecies and clarify the range of several others, showing how the region’s rugged ridges, deep canyons and the Río Grande act as natural separators. In contrast, smaller streams prove less restrictive, allowing gophers to move more freely. By linking subtle differences in skull shape and pelage to distinct habitats, the work illustrates how isolation and environment drive diversification.

Beyond cataloguing diversity, the book highlights the importance of understanding such localized variation for broader studies of evolution and for protecting the delicate ecosystems that support these hidden underground dwellers.