Name that tune: call discrimination and individual recognition in Magellanic penguins
Individual recognition via vocalizations is key to reproductive success in many species. We explored individual recognition and call discrimination in Magellanic penguins, Spheniscus magellanicus, through several playback experiments. By using two call types in multiple social contexts, we demonstrate, for the first time in a Spheniscus species, that adults and chicks can discriminate between conspecific […]
Using video playback to investigate the social preferences of rooks, Corvus frugilegus
It is important for social animals to be able to discriminate between group members. Much is known about vocal social communication through auditory playback techniques; however, visual information may also be important for conspecific recognition in the absence of auditory cues. Within the visual channel both static and dynamic features may play important roles in […]
Recognizing Facial Cues: Individual Discrimination by Chimpanzees (Pan troglodytes) and Rhesus Monkeys (Macaca mulatta)
Faces are one of the most salient classes of stimuli involved in social communication. Three experiments compared face-recognition abilities in chimpanzees ( Pan troglodytes) and rhesus monkeys ( Macaca mulatta). In the face-matching task, the chimpanzees matched identical photographs of conspecifics’ faces on Trial 1, and the rhesus monkeys did the same after 4 generalization […]
Penguins use the two–voice system to recognize each other
The sound–producing structure in birds is the syrinx, which is usually a two–part organ located at the junction of the bronchi. As each branch of the syrinx produces sound independently, many birds have two acoustic sources. Thirty years ago, we had anatomical, physiological and acoustical evidence of this twovoice phenomenon but no function was known. […]
Honest signaling of intentions: the importance of performance risk, receiver response, and prior knowledge of opponents in the threat displays of mandrills
Honest signaling of intentions was initially rejected by evolutionary game theory because it was believed to be susceptible to cheating mutants. In theory, however, conditions may exist that enable this type of signaling to remain evolutionarily stable. Two such conditions have been proposed: (1) signaling may entail performance risks by making the sender vulnerable to […]
Who wants food? Individual characteristics in raven yells
Discriminating between different individuals is considered as prerequisite for any forms of social knowledge. In birds, discriminating between conspecifics based on individual characteristics has been tested mainly in the auditory domain with territorial calls and songs for neighbour and kin discrimination but little is known about discriminating between signallers in food calls. Ravens utilize a […]
Individual recognition in a wild cooperative mammal using contact calls
Many of the mechanisms advanced to explain the evolution of intraspecific cooperative behaviour, such as reciprocity or social prestige, hinge on an animal’s ability to recognize individual group members. However, ‘true’ individual recognition, between adult group members, has never been demonstrated in a cooperatively breeding bird or mammal species. We tested whether a wild cooperative […]
Octopuses (Enteroctopus dofleini) recognize individual humans
This study exposed 8 Enteroctopus dofleini separately to 2 unfamiliar individual humans over a 2-week period under differing circumstances. One person consistently fed the octopuses and the other touched them with a bristly stick. Each human recorded octopus body patterns, behaviors, and respiration rates directly after each treatment. At the end of 2 weeks, a […]