Iowa’s 168 records for the southern red-backed vole come, almost to the last one, from a single wooded knob in the north-central farm country. Hancock County holds 135 of them, and the Pilot Knob properties supply nearly all of those: the state preserve with 101 records, the adjoining state park with 19, and the wildlife management area with 1. Neighboring Winnebago and Worth counties add the remainder. Three counties, and really one hillside, carry the species’ whole confirmed story in Iowa.
A forest island in a prairie state
The concentration is so extreme that it says something real. This vole lives on cool, shaded forest floor, working through moss, roots, and rotting logs, and Iowa’s plowed prairie offers almost none of that. Pilot Knob’s wooded slopes are an outlier, an island of timber in a sea of row crops, exactly the kind of relict patch where a northern forest animal can hang on far from the rest of its range. The records map where surveyors have trapped, but they also mark how narrow the confirmed foothold is.
A summer surge, and a guarded status
Reports crest hard in July with 92 records, bracketed by 24 in June and 38 in August. Small mammals are at their most numerous and most trappable in summer, and Pilot Knob’s survey work runs then, so the crest reflects effort as much as the voles. NatureServe ranks the species S2 in Iowa, imperiled, a striking grade for an animal considered secure across its full range. The ranking fits a species whose whole state presence leans on one patch of woods.
Full species profile
