From eavesdropping on performance to copying the behavior of others: a review of public information use

Public information (PI), a form of indirect social information, is used by individuals to estimate the quality of environmental parameters. It can be acquired in two ways. One way is by noting the performance of others. The other way it can be acquired is by noting the behavioral decisions of other individuals. Performance-based PI has been observed most often in the context of food and breeding patch estimation, as well as by individuals eavesdropping on contests between others in the context of assessing the fighting ability of opponents and the quality of mates. Evidence for the acquisition of PI from behavioral decisions of others comes mostly from studies of copying behavior, although recent work suggests that it also occurs when individuals estimate the tendency of others to be altruistic. PI use appears to be widespread across many taxa, although most work has been conducted on birds and fish. Absent from the literature are clear examples of PI use in mammals. The use of PI appears to often depend on its cost of acquisition and whether it contradicts an individual's personal prior experience. PI can be an important benefit of associating with others.