Funding: This research was supported by U.S. National Science Foundation (NSF) grants awarded to MSW at Cornell University and TSS at the Smithsonian Conservation Biology Institute (NSF grant numbers 0640732 and 1242563), and by fellowships and grants awarded to SAK from the U.S. Environmental Protection Agency, Smithsonian Conservation Biology Institute, and the Animal Behavior Society. KCG was supported on an NSF Research Experience for Undergraduates supplement.