Concatenation of ‘alert’ and ‘identity’ segments in dingoes’ alarm calls

Abstract

Multicomponent signals can be formed by the uninterrupted concatenation of multiple call types. One such signal is found in dingoes, Canis familiaris dingo. This stereotyped, multicomponent ‘bark-howl’ vocalisation is formed by the concatenation of a noisy bark segment and a tonal howl segment. Both segments are structurally similar to bark and howl vocalisations produced independently in other contexts (e.g. intra- and inter-pack communication). Bark-howls are mainly uttered in response to human presence and were hypothesized to serve as alarm calls. We investigated the function of bark-howls and the respective roles of the bark and howl segments. We found that dingoes could discriminate between familiar and unfamiliar howl segments, after having only heard familiar howl vocalisations (i.e. different calls). We propose that howl segments could function as ‘identity signals’ and allow receivers to modulate their responses according to the caller’s characteristics. The bark segment increased receivers’ attention levels, providing support for earlier observational claims that barks have an ‘alerting’ function. Lastly, dingoes were more likely to display vigilance behaviours upon hearing bark-howl vocalisations, lending support to the alarm function hypothesis. Canid vocalisations, such as the dingo bark-howl, may provide a model system to investigate the selective pressures shaping complex communication systems.

Combinatoriality in the vocal systems of nonhuman animals

“…A few mammalian species concatenate acoustic segments in a seemingly systematic way. For example, Diana monkeys ( Cercopithecus diana ), Campbell's monkeys ( Cercopithecus campbelli campbelli ), banded mongooses ( Mungos mungo ), and dingoes ( Canis lupus dingo ) produce identity‐encoding segments which can be given in isolation or concatenated with other distinct or graded elements that correlate with the animal's motivational/emotional state (e.g., socio‐positive/‐negative context) or its behavior (e.g., foraging–moving–running) (Candiotti, Zuberbühler, & Lemasson, ; Coye, Ouattara, Arlet, Lemmasson, & Zuberbühler, ; Coye, Zuberbühler, & Lemasson, ; Deaux, Allen, Clarke, & Charrier, ; Jansen, Cant, & Manser, ). From a linguistic perspective, such segments may resemble morphemes (smallest meaningful units), with the individually distinct elements representing free morphemes that can be produced as a standalone segment, or be conjoined with the behavior‐ or motivation‐coding (bound) segment (Collier et al, ).…”

Dwarf mongoose alarm calls: investigating a complex non-human animal call

“…There also exists intriguing, detailed observational data documenting call combinations in non-primate mammals (banded mongooses, Mungos mungo [32]; meerkats, Suricata suricatta [33]). In comparison to birds and primates, however, experimental verification of the structure and function of these combinations is still needed (though see [34] for an example in dingos, Canis familiaris dingo). If we are to capture the complexity of animal vocal communication systems, data on the production and perception of call combinations are required across a wide range of species and taxa.…”

Optionality in animal communication: a novel framework for examining the evolution of arbitrariness

“…Chestnut‐crowned babblers may therefore demonstrate optionality in terms of both ( i ) the function of individual elements produced in combinations (As and Bs are individually not tied to any individual function) and ( ii ) the relationships between them (different combination of the same elements results in a different function). Various examples of combinatorial optionality also appear to be present in non‐bird species such as dwarf mongooses ( Helogale parvula ) (Collier et al ., 2020 ), dingoes ( Canis lupus dingo ) (Déaux et al ., 2016 ), bonobos (Clay & Zuberbühler, 2009 ), gorillas (Hedwig et al ., 2014 ; Watson et al ., 2020 b ), chimpanzees (Leroux et al ., 2021 ) and Campbell's monkeys ( Cercopithecus campbelli ) (Schlenker et al ., 2014 ).…”