Alarm Calls

Animals commonly vocalize when threatened by a predator. These signals, usually termed alarm calls (from old Italian all arme ‘to arms’ on the approach of an enemy), have continued to bewilder and fascinate for a number of reasons, the first of which is mainly practical. In animal research, it is often difficult to break down the continuous behavioral stream into discrete and meaningful units, which can be studied systematically. Alarm calls are a rare and noticeable exception. They are highly discrete and easy to identify, making it possible to systematically study both the causes and consequences of behavior. A second motivation, related to the previous one and significant for the evolution of linguistic abilities, relates to the fact that alarm calls provide a unique tool for accessing the cognitive mechanisms underlying an animal’s behavior. Finally, alarm calls are interesting because they seem to pose a problem for evolutionary theory. They are often among the most prominent and noticeable signals in a species’ repertoire, and it seems paradoxical for individuals to behave conspicuously in the presence of a predator, thereby revealing their presence and location (e.g., Shalter, 1978). Following these considerations, this article has the following objectives. First, it summarizes research that has dealt with the problem of why animals produce seemingly maladaptive behavior in the presence of a predator. What are the evolutionary processes that have provided a selective advantage to individuals who behave this way? Second, from a cognitive– linguistic perspective, the article seeks to seize the unique opportunity that alarm calls offer, that is, to try to describe the cognitive processes that underlie call production. Several empirical studies are discussed that have aimed to investigate the relationship between the occurrence of an external event (i.e., the appearance of a predator) and the production and comprehension of these signals, particularly in the nonhuman primates. No attempt is made to provide a systematic overview of alarm calling in the various taxonomic groups, however. Instead, a handful of empirical studies have been selected, particularly those that are likely to inform the linguistically interested reader about core cognitive phenomena in nonhumans and their potential relevance for the evolution of linguistic capacities in humans.