title: Territorial raven pairs are sensitive to structural changes in simulated acoustic displays of conspecifics.
abstract: Human language involves combining items into meaningful, syntactically structured wholes. The evolutionary origin of syntactic abilities has been investigated by testing pattern perception capacities in nonhuman animals. New World primates can respond spontaneously to structural changes in acoustic sequences and songbirds can learn to discriminate between various patterns in operant tasks. However, there is no conclusive evidence that songbirds respond spontaneously to structural changes in patterns without reinforcement or training. In this study, we tested pattern perception capacities of common ravens,Corvus corax, in a habituation-discrimination playback experiment. To enhance stimulus salience, call recordings of male and female ravens were used as acoustic elements, combined to create artificial territorial displays as target patterns. We habituated captive territorial raven pairs to displays following a particular pattern and subsequently exposed them to several test and control playbacks. Subjects spent more time visually orienting towards the loudspeaker in the discrimination phase when they heard structurally novel call combinations, violating the pattern presented during habituation. This demonstrates that songbirds, much like primates, can be sensitive to structural changes in auditory patterns and respond to them spontaneously, without training.
authors.affiliation: Department of Cognitive Biology, University of Vienna, Vienna, Austria.
authors.forename: Stephan A
authors.initials: SA
authors.lastname: Reber
authors.affiliation: Department of Cognitive Biology, University of Vienna, Vienna, Austria; Konrad Lorenz Research Station for Behaviour and Cognition, University of Vienna, Grünau, Austria; Department for Psychotherapy and Biopsychosocial Health, Danube University Krems, Krems, Austria.
authors.forename: Markus
authors.initials: M
authors.lastname: Boeckle
authors.affiliation: Department of Cognitive Biology, University of Vienna, Vienna, Austria; Konrad Lorenz Research Station for Behaviour and Cognition, University of Vienna, Grünau, Austria.
authors.forename: Georgine
authors.initials: G
authors.lastname: Szipl
authors.affiliation: Department of Cognitive Biology, University of Vienna, Vienna, Austria.
authors.forename: Judith
authors.initials: J
authors.lastname: Janisch
authors.affiliation: Department of Cognitive Biology, University of Vienna, Vienna, Austria; Konrad Lorenz Research Station for Behaviour and Cognition, University of Vienna, Grünau, Austria.
authors.forename: Thomas
authors.initials: T
authors.lastname: Bugnyar
authors.affiliation: Department of Cognitive Biology, University of Vienna, Vienna, Austria.
authors.forename: W Tecumseh
authors.initials: WT
authors.lastname: Fitch
keywords: call combination; common raven; pattern perception; songbird; spontaneous response; territoriality