title: Experimental evidence for compositional syntax in bird calls.
abstract: Human language can express limitless meanings from a finite set of words based on combinatorial rules (i.e., compositional syntax). Although animal vocalizations may be comprised of different basic elements (notes), it remains unknown whether compositional syntax has also evolved in animals. Here we report the first experimental evidence for compositional syntax in a wild animal species, the Japanese great tit (Parus minor). Tits have over ten different notes in their vocal repertoire and use them either solely or in combination with other notes. Experiments reveal that receivers extract different meanings from 'ABC' (scan for danger) and 'D' notes (approach the caller), and a compound meaning from 'ABC-D' combinations. However, receivers rarely scan and approach when note ordering is artificially reversed ('D-ABC'). Thus, compositional syntax is not unique to human language but may have evolved independently in animals as one of the basic mechanisms of information transmission.
authors.affiliation: Department of Evolutionary Studies of Biosystems, SOKENDAI (The Graduate University for Advanced Studies), Kamiyamaguchi 1560-35, Hayama, Kanagawa 240-0193, Japan.|Department of Life Science, Rikkyo University, Nishi-Ikebukuro 3-34-1, Toshima, Tokyo 171-8501, Japan.
authors.forename: Toshitaka N
authors.initials: TN
authors.lastname: Suzuki
authors.affiliation: Department of Ecology and Genetics, Uppsala University, Norbyvägen 18D, SE-752 36 Uppsala, Sweden.
authors.forename: David
authors.initials: D
authors.lastname: Wheatcroft
authors.affiliation: Anthropological Institute and Museum, University of Zurich, Winterthurerstrasse 190, 8057 Zürich, Switzerland.
authors.forename: Michael
authors.identifier: http://orcid.org/0000-0002-2220-2637
authors.initials: M
authors.lastname: Griesser
mesh_terms: D000818:Animals; D000835:Animals, Wild / Q000502:physiology; D005260:Female; D008297:Male; D020308:Songbirds / Q000502:physiology*; D014828:Vocalization, Animal