Oregon’s 42 Preble’s shrew records are really one place’s story: Harney County, the big sagebrush-and-marsh basin that holds Malheur National Wildlife Refuge, accounts for 36 of them. Grant, Klamath, and Lake counties chip in single digits, and everything sits east of the Cascades. That east-side lean isn’t survey luck alone. This is a shrew of dry country, one of the smallest mammals in North America, making its living in the cool, damp seams hidden inside the sagebrush steppe.
Damp pockets in dry country
Preble’s shrew doesn’t need wet land so much as wet spots: the shaded litter under a willow clump, the cool thatch along a marsh edge, the moist soil beneath deep grass. The Malheur basin offers those in abundance, which is why refuge traplines keep finding it. The suggested viewing ground includes Klamath Marsh and the Willamette Valley refuges west of the Cascades, but no west-side county has produced a record in this dataset, so treat those as plausible rather than proven ground.
A June trapline season
Twenty-nine of the 42 Oregon records landed in June, with July a distant second. Shrews this small are almost never documented without a formal survey, and early summer is when biological crews work the basin, so the calendar reflects trapline season more than any shrew timetable. These animals don’t hibernate. They hunt insects and spiders year-round, whatever the record says.
Status in Oregon
NatureServe ranks Preble’s shrew S3, vulnerable, in Oregon. It’s native, and at about three grams it’s easy to overlook even where it’s doing fine. The records can’t say how many there are, only that the Harney basin is the one place in the state where anyone has looked hard enough to find it consistently.
Full species profile
