For decades, bats have defied scientists’ best ideas for keeping track of individuals, which is crucial to wildlife research. Banding (either legs or forearms) can result in injury, and banded bats are seldom recaptured anyway. Tattoos take too long. Holes punched in their wings are only visible for 5 months. Electronic tags have to be close to a reading device to work.
Sybill Amelon, a research wildlife biologist with the Forest Service’s Northern Research Station, and her colleagues have discovered a means of identifying individual bats that may be as unique as fingerprints: bats’ wings.
Bats’ wing tissue is crisscrossed by what appear to be small lines; these lines are called collagen–elastin bundles, and they make wing tissue strong yet flexible enough for flight. Amelon and University of Missouri researchers Sarah Hooper and Kathryn Womack analyzed little brown bats, northern long-eared bats, big brown bats, and tricolored bats to determine whether wing prints showing the crisscross of collagen-elastin bundles could satisfy scientific standards for measuring unique characteristics: universality, distinctiveness, permanence, and collectability.
Wing tissue is a prime target of the fungus that causes white-nose syndrome (WNS) – (Pseudogymnoascus destructans, or Pd) – however researchers found that even when wings were damaged, the collagen–elastin bundle network maintained the original wing print pattern when they healed. With basic training, people were able to successfully identify bats based on wing photographs with a success rate of 96 percent.
If widely applied, this technique would be an easily employable identification system for bats that does not require adding markers to the animal that could alter their behavior or impair their health.
The study, “Bat wing biometrics: using collagen–elastin bundles in bat wings as a unique individual identifier,” is available at: https://www.nrs.fs.fed.us/pubs/54707