Evidence of individual discrimination in the maned wolf long-distance extended-bark.

The acoustic channel is an efficient long-distance signalling system that may be especially effective for animals moving in the dark in a vast home range. The maned wolf's extended-bark is a long-range vocalization that functions as a mechanism to increase spatial distance among conspecifics as well as to enable pair-mate reunion. Individual variations in this vocalization have been reported, but the possibility that they can be perceived and used by the species has never been tested. In our study, we used ABAB playback experiments to test if captive maned wolves could perceive individual variations. We ran 19 playback sessions with ten different subjects from six different zoos. After discarding nine sessions that did not fulfil minimal experimental conditions, in all except two of the ten valid trials, the subjects responded with displaying Oriented Attention. To our knowledge, this is the first demonstration that the maned wolf is capable of discriminating among extended-barks of different individuals.