Evidence that bottlenose dolphins can communicate with vocal signals to solve a cooperative task

Abstract

Cooperation experiments have long been used to explore the cognition underlying animals' coordination towards a shared goal. While the ability to understand the need for a partner in a cooperative task has been demonstrated in a number of species, there has been far less focus on cooperation experiments that address the role of communication. In humans, cooperative efforts can be enhanced by physical synchrony, and coordination problems can be solved using spoken language. Indeed, human children adapt to complex coordination problems by communicating with vocal signals. Here, we investigate whether bottlenose dolphins can use vocal signals to coordinate their behaviour in a cooperative button-pressing task. The two dolphin dyads used in this study were significantly more likely to cooperate successfully when they used whistles prior to pressing their buttons, with whistling leading to shorter button press intervals and more successful trials. Whistle timing was important as the dolphins were significantly more likely to succeed if they pushed their buttons together after the last whistle, rather than pushing independently of whistle production. Bottlenose dolphins are well known for cooperating extensively in the wild, and while it remains to be seen how wild dolphins use communication to coordinate cooperation, our results reveal that at least some dolphins are capable of using vocal signals to facilitate the successful execution of coordinated, cooperative actions.

Vocal signals facilitate cooperative hunting in wild chimpanzees

“…We show that this effect was not a by-product of a larger number of hunters, but, rather, it was independently driven by the occurrence of barks. This suggests that the use of communication expedited the achievement of the desired outcome, supporting previous findings in distantly related species ( 7 , 47 ). The mechanisms driving the association between barking and faster kills are unknown but could include (i) the barks facilitating faster decisions in party members to join the hunt and (ii) the barks startling monkey prey and driving them toward their escape routes, making them easier to catch.…”

“…A prevailing hypothesis is that human language and cooperation coevolved, with advances in communication facilitating more complex cooperative behavior, which, in turn, selected for more sophisticated linguistic skills (3)(4)(5). Such an interdependence between group-level cooperation and communication seems to have evolved convergently, albeit more simply, in distantly related species including Indo-Pacific bottlenose dolphins (Tursiops aduncus), shedding light on the shared selection pressures driving this social behavior (1,(6)(7)(8). What remains unclear, however, is whether, within the primate order, the coevolution of communication and cooperation is a derived feature of the hominin lineage or whether its basic building blocks may be found in our closest living primate relatives.…”

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

“…Furthermore, individuals learn to reproduce the whistles of their affiliates, thereby facilitating identification of close social partners and the maintenance of those relationships (Janik, 2014 ). These whistles were even found to be produced spontaneously to facilitate coordinated action in a cooperative button‐pushing task (King et al ., 2021 ), suggesting that they either serve multiple functions naturally, or can be made to do so under certain conditions. Only a handful of other non‐avian species have been found to spontaneously (i.e.…”

The singing question: re‐conceptualizing birdsong

“…However, just as we argue vocal learning is not a dichotomy in birds, there is growing evidence that vocal learning is a continuum in mammals as well. Vocal learning is less common in mammals (Martins & Boeckx, 2020; Vernes & Wilkinson, 2020; Barker et al ., 2021) and like the oscines, some mammals also have a tremendous amount of social modulation of vocal communication (Fischer et al ., 2020; Buffenstein, 2021; King et al ., 2021; Rauber & Manser, 2021). Thus there is potential for greater direct comparative work between songbirds and mammals.…”