A live bat can also provide more information than a recorded call. When Slough captures a bat, he attaches bands to their forearms so that they can be identified if they are recaptured. He also takes tissue samples from the bats, which he sends to bat researchers at the University of Alaska. They are using genetic studies to track where bats migrate. But sometimes not many bats end up in the nets because they use very open habitats in the Yukon.
Most bats are live-captured near roosts in abandoned buildings.
When he set up his mist nets by the La Biche River in June, for example, he did not capture any bats, possibly because not many bats had migrated back to the area yet. But the bat detector did pick up one lone call. It hit a high of 100 Kilohertz, which is a much higher frequency than any sound emitted by a little brown myotis, whose calls do not exceed 70 Kilohertz. At Morris Lake the bat detector recorded a whole series of calls that were of lower frequency than the little brown myotis, which told him that a larger bat had made the calls. Slough does not think that the presence of new bat species in the Yukon is very surprising as very little is known about bats here.