The Yuma myotis is Arizona’s water-bound little brown bat, and it slips past most observers. Open occurrence databases hold 319 records for it in the state, of which only 10 are iNaturalist photos. The rest come from netting and acoustic surveys along the rivers and lakes it depends on.
Tied to open water
Few bats are as closely bound to water as this one. It forages by skimming low over the smooth surface of streams, ponds, and reservoirs, snatching midges and other soft insects as they rise, and it roosts by day in bridges, buildings, caves, and cliffs close to that water. In Arizona its records follow the rivers and the wetter high country, concentrating in Yavapai, Graham, and Mohave counties and along the Grand Canyon reach of the Colorado River.
A warm-season presence
Detections cluster in the warm months and fall off in winter, when the bat shifts into hibernation and torpor. The empty cold-season record is dormancy rather than departure. NatureServe ranks the Yuma myotis S3, vulnerable, in Arizona while its global rank is more secure, a gap that reflects how patchily this water-tied bat has been surveyed here.
Common questions
What makes the Yuma myotis stand out among small bats? Its habits, more than its looks. Almost any small bat coursing back and forth just above a calm Arizona water surface at dusk is a strong candidate for this species.
Full species profile
