Researchers Cori Lausen and Maleen Mund step out of the warm spring sun and into a dimly lit workshop. The only light streams in through the doorway behind them and a few dusty windows. It’s been a cool start to the season in the Lower Mainland, but some bats have already emerged from their winter hibernation. A couple dozen are roosting in cozy clusters in the rafters of this old, wood building near Hayward Lake, about 35 miles east of Vancouver, British Columbia, in Canada.
Mund, a field technician working with Lausen, a bat biologist, fixes a swab to the end of a wooden dowel and climbs up a ladder. As she scrapes the swab back and forth just below the bats, they squeak softly, as if in protest. Disturbed from its daytime snooze, one bat takes flight, circling the room before settling back to roost. Lausen offers a quiet …