Pyow but not hack calls of the male putty-nosed monkey (Cercopithcus nictitans) convey information about caller identity

The debate about altruism lacks adult judgements. Any supposedly altruistic response should be judged by the latency of the response, by the number of bystanders, by the genetic relatedness between the altruist and the beneficiary, and by the amount of social contact between the altruist and the beneficiary and between the altruist and any bystander,…