Imagine waking up in a panic from a deep sleep in response to a predator in the area. Now imagine doing that but having to rewarm your body temperature back to a normal level in order to flee or fight off the predator. This is exactly what silver-haired bats (Lasionycteris noctivagans) do, and surprisingly they are able to do it the quickest out of any mammal measured to date. 

To figure this out, I and other researchers at the University of Winnipeg measured body temperature changes in response to an acute stress in three different situations. The first was during the night as the bats were out searching for food, the second was under normal resting conditions during the day, and the third was during the day when the bats were cold (torpid). In all cases, we measured body temperatures immediately, then measured them again after five minutes of handling. The handling induced the same stress response the bats would have when accosted by a predator.

Surprisingly, we found that bats feeding in the night decrease their body temperature in response to handling, potentially to avoid overheating. Bats resting during the day increased body temperatures moderately, as expected. Very surprisingly, however, body temperatures increased extremely quickly when they were cold. This quick response in body temperature change may reflect this species' ability to deal with predators and people.