The silver-haired bat is an occasional presence in Colorado’s night skies. Open occurrence databases hold 337 records for it, and tellingly only 37 are iNaturalist photos. This is a bat known far better from museum specimens and acoustic detectors than from anyone’s camera.
A migratory tree bat passing through
Silver-haired bats are long-distance travelers rather than year-round residents, and the Colorado record reflects a species on the move. Each one roosts alone under loose bark or in a tree cavity, so it leaves none of the clustered colony sign that makes cave bats easy to count. The records scatter widely as a result, from the canyon country of Montezuma and Moffat counties to the northern Front Range and the mountain parks, wherever forest, water, and darkness line up.
Two pulses a year
Sightings arrive in two waves, one in late spring and one in early fall, and both are migration windows. The bat pushes north through Colorado as the season warms and drifts back south in autumn, and the detectors and observers catch it in transit. Between the two pulses the summer roosting animals go quiet and nearly impossible to find, tucked behind a few centimeters of peeling bark on a dying tree.
Status and pressure in Colorado
The silver-haired bat is native to Colorado but carries a state rank of S3, vulnerable, a notch below the secure rating most of the state’s common mammals hold. It is widespread across North America, yet its biology leaves little margin: it migrates long distances through open airspace, roosts alone, and raises only one small litter a year. Wind-energy turbines are the best-documented source of mortality, and because those losses are spread thinly across many sites and migration routes, they are hard to measure and easy to underestimate.
Full species profile
