Only 5 big brown bat records turn up in North Dakota’s occurrence data, all of them iNaturalist sightings, 3 also carried in GBIF. For a bat that tolerates almost any landscape, that thin count says more about how few people are out looking for bats after dark than about scarcity.
Rock crevices standing in for caves
North Dakota has little in the way of true caves, so big brown bats here likely lean on the next best thing: the crevices, fissures, and undercut ledges in the scoria buttes and sandstone outcrops of the Little Missouri Badlands, where Billings County holds one of the state’s five records. Elsewhere, the wetland refuges at J. Clark Salyer and Chase Lake offer a different draw, open water and marsh edges thick with the mosquitoes, midges, and other night-flying insects this bat hunts on the wing.
A thin calendar
Five records are too few to show a season. They fall in April, May, August, and December, with two in August. Summer is when big brown bats form maternity colonies, and warm summer nights bring the heaviest insect activity for a species that needs to eat close to its own body weight in insects to get through a night. Winter records are nearly absent, consistent with a bat that hibernates through the cold rather than staying active.
Status in North Dakota
The big brown bat carries no numeric NatureServe rank in North Dakota, SNR, unranked, though it’s secure globally at G5. It’s native to its North Dakota range, one of the most adaptable bats in the state even where its record count stays thin.
Full species profile
