Wyoming’s silky pocket mouse file holds just 10 records, half of them from Converse County, where Thunder Basin National Grassland spreads sandy grassland and sagebrush across the state’s northeast quarter. This is one of the smallest rodents in North America, a night-working seed collector lighter than two nickels, and Wyoming marks the northern edge of its range.
Soft fur, sandy floor
The silky pocket mouse earns its name from an unusually smooth, soft coat, and its living from sand. It needs loose, diggable soil for its burrows and open ground with scattered grass and shrubs for foraging. Like its relatives, it carries seeds home in fur-lined cheek pouches that open outside the mouth, keeping the harvest dry until it’s cached underground. Thunder Basin’s mix of sandy prairie and stream corridors is the closest thing Wyoming has to classic habitat, and the record count there reflects it.
An August crest
Six of the 10 Wyoming records landed in August, with July close behind. By late summer the year’s young are out on their own and traplines are running, so the crest mixes real animal activity with survey season. Pocket mice ride out the coldest stretches in torpor below ground, which is one reason winter adds nothing to the record.
Status in Wyoming
NatureServe ranks the species S3, vulnerable, in Wyoming, while globally it’s considered secure. It’s native here, and the outlying single records from Natrona, Sweetwater, and Albany counties hint it could turn up in any of the state’s sandy basins where nobody has yet run a trapline. Ten records can’t say how many mice there are, only that Wyoming’s northern outpost of this little pocket mouse is still producing reports.
Full species profile
