Our newest paper is Common vampire bat contact calls attract past food-sharing partners in the journal Animal Behaviour. You can download the paper for free until June 12, 2016 here at this link: http://authors.elsevier.com/a/1SwLKmjLdkSa
It’s a simple playback experiment where we disentangled kinship and food sharing as predictors of a bat’s attraction to calls of different individuals. Subject bats chose between moving towards and spending time near two ultrasonic speakers pretending to be different bats. With the simulated callers were paired by kinship, we found that bats were biased to callers that had fed them more. But when callers were paired by sharing history, bats were not biased towards closer kin. The playback responses suggest that the vampire bats vocally recognized individuals, and this is a further illustration of how food sharing history can overshadow kinship in determining social bonds and behavior.