Syntax-like Structures in Maternal Contact Calls of Chestnut-Crowned Babblers (Pomatostomus ruficeps)

Abstract The combination of meaning-bearing units (e.g., words ) into higher-order structures compound and phrases) is integral to human language. Despite this central role syntax in language, little known about its evolutionary progression. Comparative data using animal communication systems offer potential insights, but only a handful species have been identified combine meaningful calls together larger signals. We investigated candidate for syntax-like structure the highly social chestnut-crowned babbler ( Pomatostomus ruficeps ). Using behavioral observations, acoustic analyses, playback experiments, we test whether form function maternal contact modified by combining core “piping” elements such with at least one other call element or call. Results from analyses (236 analysed 10 individuals) suggested that piping can be flexibly initiated either “peow ” middle-distance adult “begging” “peow-pipe” “beg-pipe” calls. Behavioral responses playbacks (20 trials 7 groups) natural peow-pipe beg-pipe were comparable those artificially generated versions each peow begging contexts. Furthermore, (34 three forms (piping alone, peow-pipe, beg-pipe) differed. Together these suggest meaning encoded used contexts so provide rare empirical evidence syntactic-like structuring nonhuman animal.