Animal linguistics: Exploring referentiality and compositionality in bird calls

Bare and Constructional Compositionality

This paper proposes a typology of compositionality as manifest in human language and animal communication. At the heart of the typology is a distinction between bare compositionality, in which the meaning of a complex expression is determined solely by the meanings of its constituents, and constructional compositionality, in which the meaning of a complex expression is determined by the meanings of its constituents and also by various aspects of its structure. Bare and constructional compositionality may be observed in human language as well as in various animal communication systems, including primates and birds. Architecturally, bare compositionality provides the foundations for constructional compositionality, while phylogenetically, bare compositionality is a potential starting point for the evolution of constructional compositionality in animal communication and human language.

Overlooked evidence for semantic compositionality and signal reduction in wild chimpanzees (Pan troglodytes)

Recent discoveries of semantic compositionality in Japanese tits have enlivened the discussions on the presence of this phenomenon in wild animal communication. Data on semantic compositionality in wild apes are lacking, even though language experiments with captive apes have demonstrated they are capable of semantic compositionality. In this paper, I revisit the study by Boesch (Hum. Evol. 6:81–89, 1991) who investigated drumming sequences by an alpha male in a chimpanzee (Pan troglodytes) community in the Taï National Park, Côte d’Ivoire. A reanalysis of the data reveals that the alpha male produced semantically compositional combined messages of travel direction change and resting period initiation. Unlike the Japanese tits, the elements of the compositional expression were not simply juxtaposed but displayed structural reduction, while one of the two elements in the expression coded the meanings of both elements. These processes show relative resemblance to blending and fusion in human languages. Also unlike the tits, the elements of the compositional expression did not have a fixed order, although there was a fixed distribution of drumming events across the trees used for drumming. Because the elements of the expression appear to carry verb-like meanings, the compositional expression also resembles simple verb-verb constructions and short paratactic combinations of two clauses found across languages. In conclusion, the reanalysis suggests that semantic compositionality and phenomena resembling paratactic combinations of two clauses might have been present in the communication of the last common ancestor of chimpanzees and humans, not necessarily in the vocal modality.