The Northern Grasshopper Mouse is unusual among mice because most of its diet consists of animals, including insects and scorpions. It rests in burrows by day and is active at night.
Its underside is white, while the back ranges from brown to pinkish. The short tail has a white tip. Juveniles have gray dorsal fur that changes to cinnamon as they mature.
The Northern Grasshopper Mouse (Onychomys leucogaster) had a significantly higher capture rate at active cropland STER than at native shortgrass prairie CPER in Colorado. Among four species that signaled agricultural habitat, the authors considered it the strongest indicator.
The 95.3% figure is the estimated chance that a trapping round came from STER when the mouse was found in that round. It was caught in all 39 STER rounds; CPER had 52 rounds. The sites were nonadjacent; trapping began at CPER in 2013 and STER in 2014, with records through 2023. Box traps were usually set for three consecutive nights monthly or every other month. Capture rates were adjusted to 100 trap-nights; one trap set for one night counts as one trap-night.
An extinction-risk assessment has not been added yet.