When you're studying wildlife, it's important to have a way of differentiating between individual animals. Marking them with things like ear tags is one approach, although applying those tags can be harmful to smaller animals, and wearing the tags may alter the creatures' natural behaviour. With that in mind, scientists have discovered that bats can be told apart via their unique "wing prints."
Working with University of Missouri researchers Sarah Hooper and Kathryn Womack, USDA (US Department of Agriculture) Forest Service scientist Sybill Amelon studied the wings of little brown bats, northern long-eared bats, big brown bats, and tricolored bats. More specifically, the scientists were scrutinizing small lines in the wing membranes known as collagen-elastin bundles.
These allow wing tissue to be strong yet flexible enough for flight, and their patterns are reportedly as unique to each bat as fingerprints are to each person. Even though that tissue is often attacked by the fungus behind white-nose syndrome – a disease that's killing bats throughout North America – the collagen-elastin bundle patterns remain intact and visible.
According to the USDA, people who received basic training were able to identify individual bats based on wing photos with a 96 percent success rate. Perhaps the system could even be computerized, as has been the case with the identification of great white sharks based on photos of their dorsal fins.