The Yuma myotis is Arizona’s water-bound little brown bat, and it slips past most observers. Open occurrence databases hold 14 records for it in the state, 10 of them 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 few records are scattered across seven counties, with Maricopa holding 6, Navajo and Coconino 2 each, and the rest single records.
A warm-season presence
Detections lean toward the warm months, though a handful of records can’t pin down a season, and winter is when the bat shifts into hibernation and torpor. A thin 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
