Speciation of the Wandering Shrew

This scholarly report tackles a long‑standing puzzle in North American mammalogy: how the various members of the wandering shrew complex are related to one another. By revisiting the classic group outlined by early 20th‑century taxonomists, the author re‑examines species such as Sorex vagrans, S. obscurus, and their coastal and mountain counterparts, offering fresh insight into their classification.

The study is built on an impressive sample of more than 3,400 museum skins and skulls, measured for external dimensions and a suite of cranial traits. Detailed graphs and illustrations trace tooth wear, rostrum growth, and geographic distribution, while statistical comparisons tease apart age, sex, and regional variation. The resulting phylogenetic framework clarifies which forms truly represent distinct species and which are merely local variants, providing a solid foundation for future ecological and evolutionary work.