Western harvest mice build small woven nests just above the ground, tucked into dense marsh-edge and wet-meadow grass rather than below it. That habit fits the two wetland refuges anchoring this record set: Cheyenne Bottoms and Quivira National Wildlife Refuge both hold extensive stands of cattail-fringed wet meadow and moist grassland where a mouse this size can move under cover without crossing open ground.
Recorded sightings climb steadily from a handful in spring to a July peak of 136, still strong through August and September, then fall off fast by November. That pattern tracks when people are out doing wetland surveys and when young mice are dispersing, not a sign the species vanishes in winter; harvest mice stay active year-round, just under heavier cover.
One reliable field mark separates it from other small grassland mice up close: grooved upper incisors. NatureServe lists it S5, secure, across Kansas.
Full species profile
