Meeting Abstract

P1.123  Wednesday, Jan. 4  How the bat got its stripes: roosting ecology and the evolution of pelage markings in bats DIAL, T.O.*; SANTANA, S.E.; EITING, T.P.; ALFARO, M.E.; University of California Los Angeles

Although bats are not renowned for their diversity in color, multiple lineages have evolved striking facial and body pelage makings, including spots, stripes, neck bands and countershading. Researchers have hypothesized that these markings mainly evolved for crypsis, but this idea has never been tested in a quantitative and comparative context. We present the first large comparative study integrating data on roosting ecology (roost type and colony size) and pelage coloration patterns across bats, and explore the hypothesis that the evolution of bat pelage markings is associated with roosting ecologies that benefit from crypsis. We find that lineages that roost in the vegetation have evolved pelage markings, especially stripes and neck collars. These markings may function in crypsis through disruptive coloration and a type of anteroposterior countershading that might be unique to bats. We also demonstrate that lineages that live in larger colonies and are larger in size tend not to have some types of pelage markings. This result further suggests that the evolution of markings might be related to predation pressures, which would decrease in larger colonies due to the predator dilution effect and a lower number of potential predators in larger animals. Although social functions for pelage color patterns are also possible, our work provides strong support for the idea that roosting ecology has driven the evolution of pelage markings in bats.