Semantic communication in birds: evidence from field research over the past two decades

Abstract

What do animal signals mean? This is a central question in studies on animal communication.Research into the semantics of animal signals began in 1980, with evidence that alarm calls of a non-human primate designated predators as external referents. These studies have challenged the historical assumption that such referential signaling is a unique feature of human language and produced a paradigm shift in animal communication research. Over the past two decades, an increasing number of field studies have revealed similar complexity in anti-predator communication of birds. The acoustic structures of avian alarm calls show a high degree of variation in pitch, duration, shape, and repetition rate. In addition to such distinct and graded variations, several birds combine discrete types of notes or calls into higher complex sequences. These variations in alarm calls are typically associated with the predator's attributes, such as predator type and distance, and receivers respond to them with appropriate anti-predator behaviors. Although alarm calls of several bird species, as well as those of monkeys, appear to denote predator attributes, almost nothing is known about the cognitive processes that underlie the production and perception of these signals. In this review, I explore the existing evidence for referential signaling in birds and highlight the importance of the cognitive approach to animal communication research. I hope this review will promote further investigations of alarm-calling behavior in birds and will help enhance our understanding of the ecology and evolution of semantic communication.

Alarm call‐based discrimination between common cuckoo and Eurasian sparrowhawk in a Chinese population of great tits

“…Additionally, they displayed stronger responses to alarm calls than to song (control). These results are consistent with bird alarm calls encoding information on threats and that such information could be conveyed to conspecific individuals (Lind, Jöngren, Nilsson, Alm, & Strandmark, ; Suzuki, , , , ; Suzuki & Ueda, ). As great tits behave differently in response to these three categories of playback stimuli, we suggest that they distinguish between these calls and likely relate them to the different intruders eliciting the specific alarm call types.…”

“…Birds usually make alarm calls when encountering danger, and alarm calls contain information regarding the type, body size, distance, and threat level of enemies (e.g., Courter & Ritchison, ; Griesser, ; Hollén & Manser, ; Lind et al., ; Strnad, Němec, Veselý, Sýkorová, & Fuchs, ; Suzuki, , , , ; Suzuki & Ueda, ; Templeton et al., ). Call types (Suzuki, ; Suzuki & Ueda, ; Templeton et al., ), note type combinations (Suzuki, ), calling rate (Wilson & Mennill, ), number of notes per call and lowest frequency of a call (Leavesley & Magrath, ), and compositional syntax of alarm calls (Suzuki et al., ) may be used to pass on corresponding alarm information.…”

Bioacoustic monitoring of animal vocal behavior for conservation

“…By definition, functionally referential calls meet two criteria: (a) they refer to, and possibly convey information about, a specific external threat and (b) they elicit in receivers antipredator behaviors that can be repeated in isolation (Macedonia & Evans, 1993;Smith, 2017;Suzuki, 2016;Townsend & Manser, 2013). By definition, functionally referential calls meet two criteria: (a) they refer to, and possibly convey information about, a specific external threat and (b) they elicit in receivers antipredator behaviors that can be repeated in isolation (Macedonia & Evans, 1993;Smith, 2017;Suzuki, 2016;Townsend & Manser, 2013).…”

Naive Juveniles Are More Likely to Become Breeders after Witnessing Predator Mobbing

“…Some species have innate predator recognition, where individuals exhibit appropriate antipredator behaviors already during the first predator encounter in life (Curio 1993;Li 2002;Storm and Lima 2010). Innate predator recognition is especially beneficial when trial-and-error learning is fatal, in solitary species, or in social species where naive juveniles do not have the opportunity to learn from knowledgeable individuals (Li 2002;Hollén and Radford 2009;Suzuki 2016). In contrast, individuals in many social species learn to respond appropriately to predators from other individuals (Caro 2005;Hollén and Radford 2009) or modify existing templates depending on the response of knowledgeable individuals (Cheney and Seyfarth 1980).…”