How can you tell if these magnificent microbats are in your area? Unless you are up late watching the aerial acrobatics in your yard, bats will go unnoticed most of the time and we need to look for signs that they occupy the area. In roosts we look for a variety of signs aside from live bats flying about. A major telltale sign of bats is their guano. For insectivorous bats, the guano is dry and powdery. You may find guano on walls, under roosting locations or in an attic. A secondary sign is the presence of insect carcasses at or near roosting locations (moth wings are common). A tertiary sign is the presence of urine staining at entrances and below older roost locations.
Additionally, an odd sign for a healthy colony is the presence of bat carcasses in various stages of decay. We would not want to see a large mass of similar stage carcasses, but a healthy population will display some mortalities. If you are very lucky, you may even see a few hairless newborns in the first few weeks of their lives. In roosting areas that are much older, we often see the presence of wing bones and skulls below the healthy population.
NAIT’s Nanotechnology students have been involved in assisting us with documenting identification features of Alberta Bat skeletal structures found in various locations across the province. Pairing this imagery with carbon dating, we are slowly learning just how long bats occupy the same roosting locations.