Injury rates resulting from bat bands: implications for increasing our understanding of bat ecology

Abstract The ability to identify and track individuals is a critical tool for understanding population demographics and developing effective wildlife management strategies. Forearm bands have been a critical mark–recapture methodology for bats for almost a century despite some concerns that banding may have a negative impact on bat populations. We used banding data from a long-term demographic study of Little Brown Myotis (Myotis lucifugus) to determine rates of band loss and band injury for plastic split-ring (3.5 mm inner diameter), small (2.9 mm) aluminum flanged, and 2 types of large (4.2 mm) aluminum flanged forearm bands (USFWS #2 and Lambourne). We found that bats with plastic split-ring bands and larger aluminum bands (both USFWS #2 and Lambourne) had higher rates of band injuries than bats banded with the smaller (2.9 mm) bands. We also found that the loss rate of the larger 4.2 mm bands was significantly higher than for the smaller bands. Bats recaptured with band-related injuries showed high rates of recovery, with 88% of subsequent recaptures showing no evidence of prior injury. Bats banded when they were young-of-the-year had no detectable difference in band loss rates and lower rates of both band chewing and band-related injury compared to bats initially captured as adults. Our data suggest that the perception of banding having a negative impact on bats such as M. lucifugus is likely due to disturbance related to the banding protocol and not due to injuries or mortality of individual bats. Our data suggest that forearm bands, when properly sized and secured to the wing, continue to be a reliable and low-risk marking method for some bat species.