Frequent melanism in Geoffroy's bat (Myotis emarginatus, Geoffroy 1806)

(Uploaded by Plazi for the Bat Literature Project) Melanistic, or otherwise atypically coloured bats, are rarely observed. Here we report on a survey of melanistic individuals of Myotis emarginatus (Geoffroy's bat) in the Northwestern edge of its distribution. Across the sampled region, 31 sites and over 3000 individuals of M. emarginatus were observed. Overall, melanism was found in approximately 2-4% of the populations. To our knowledge this is the highest proportion of melanistic individuals recorded in any bat species thus far. Such large levels of melanism may indicate a recent bottleneck in the population. Further research on the genetic structure and behaviour of this population may help identify the possible causes and consequences of this peculiarity.