In animal communication research, vocal labeling refers to incidents in which an animal consistently uses a specific acoustic signal when presented with a specific object or class of objects. ...Labeling with learned signals is a foundation of human language but is notably rare in nonhuman communication systems. In natural animal systems, labeling often occurs with signals that are not influenced by learning, such as in alarm and food calling. There is a suggestion, however, that some species use learned signals to label conspecific individuals in their own communication system when mimicking individually distinctive calls. Bottlenose dolphins (Tursiops truncatus) are a promising animal for exploration in this area because they are capable of vocal production learning and can learn to use arbitrary signals to report the presence or absence of objects. Bottlenose dolphins develop their own unique identity signal, the signature whistle. This whistle encodes individual identity independently of voice features. The copying of signature whistles may therefore allow animals to label or address one another. Here, we show that wild bottlenose dolphins respond to hearing a copy of their own signature whistle by calling back. Animals did not respond to whistles that were not their own signature. This study provides compelling evidence that a dolphin’s learned identity signal is used as a label when addressing conspecifics. Bottlenose dolphins therefore appear to be unique as nonhuman mammals to use learned signals as individually specific labels for different social companions in their own natural communication system.
Over the years, playback experiments have helped further our understanding of the wonderful world of animal communication. They have provided fundamental insights into animal behaviour and the ...function of communicative signals in numerous taxa. As important as these experiments are, however, there is strong evidence to suggest that the information conveyed in a signal may only have value when presented interactively. By their very nature, signalling exchanges are interactive and therefore, an interactive playback design is a powerful tool for examining the function of such exchanges. While researchers working on frog and songbird vocal interactions have long championed interactive playback, it remains surprisingly underused across other taxa. The interactive playback approach is not limited to studies of acoustic signalling, but can be applied to other sensory modalities, including visual, chemical and electrical communication. Here, I discuss interactive playback as a potent yet underused technique in the field of animal behaviour. I present a concise review of studies that have used interactive playback thus far, describe how it can be applied, and discuss its limitations and challenges. My hope is that this review will result in more scientists applying this innovative technique to their own study subjects, as a means of furthering our understanding of the function of signalling interactions in animal communication systems.
In Shark Bay, Western Australia, male bottlenose dolphins form a complex nested alliance hierarchy. At the first level, pairs or trios of unrelated males cooperate to herd individual females. ...Multiple first-order alliances cooperate in teams (second-order alliances) in the pursuit and defence of females, and multiple teams also work together (third-order alliances). Yet it remains unknown how dolphins classify these nested alliance relationships. We use 30 years of behavioural data combined with 40 contemporary sound playback experiments to 14 allied males, recording responses with drone-mounted video and a hydrophone array. We show that males form a first-person social concept of cooperative team membership at the second-order alliance level, independently of first-order alliance history and current relationship strength across all three alliance levels. Such associative concepts develop through experience and likely played an important role in the cooperative behaviour of early humans. These results provide evidence that cooperation-based concepts are not unique to humans, occurring in other animal societies with extensive cooperation between non-kin.
In recent decades, a number of studies have examined whether various non-human animals understand their partner's role in cooperative situations. Yet the relatively tolerant timing requirements of ...these tasks make it theoretically possible for animals to succeed by using simple behavioural strategies rather than by jointly intended coordination. Here we investigated whether bottlenose dolphins could understand a cooperative partner's role by testing whether they could learn a button-pressing task requiring precise behavioural synchronization. Specifically, members of cooperative dyads were required to swim across a lagoon and each press their own underwater button simultaneously (within a 1 s time window), whether sent together or with a delay between partners of 1–20 s. We found that dolphins were able to work together with extreme precision even when they had to wait for their partner, and that their coordination improved over the course of the study, with the time between button presses in the latter trials averaging 370 ms. These findings show that bottlenose dolphins can learn to understand their partner's role in a cooperative situation, and suggest that the behavioural synchronization evident in wild dolphins' synchronous movement and coordinated alliance displays may be a generalized cognitive ability that can also be used to solve novel cooperative tasks.
Cetaceans represent an evolutionary peak in terms of their cognitive capacities, complex communication systems and their structured, multilevel societies. However, the difficulty of observing their ...behaviour underwater means that studying whale and dolphin sociality in the wild poses some significant methodological challenges.
Traditionally, playback experiments have been used to explore aspects of communication and cognition in whales and dolphins, particularly with trained animals under human care. However, while these studies have provided major breakthroughs in our understanding of cetacean social cognition, it is difficult to know whether these findings generalize to wild animals.
In recent years, new state‐of‐the‐art technology (drones and non‐invasive sound and movement tags) have revolutionized the field of marine mammal behaviour, providing unparalleled information on the fine‐scale behaviour of individuals in the wild. Here, we review the state of the field, combining published studies with our own extensive experience, to demonstrate how these new technologies fundamentally change the behavioural metrics that we are able to measure; allowing us to move from categorical observations to quantifying fine‐scale changes in movement, activity and vocal behaviour.
We discuss how conducting playback experiments alongside these new technologies combines rigorous experimental design with strong ecological validity and increased reproducibility and can be adapted for many social species, setting the standard for high‐calibre, field‐based experiments that explore animal social cognition in the wild.
Synchronous displays are hallmarks of many animal societies, ranging from the pulsing flashes of fireflies, to military marching in humans. Such displays are known to facilitate mate attraction or ...signal relationship quality. Across many taxa, synchronous male displays appear to be driven by competition, while synchronous displays in humans are thought to be unique in that they serve a cooperative function. Indeed, it is well established that human synchrony promotes cooperative endeavours and increases success in joint action tasks. We examine another system in which synchrony is tightly linked to cooperative behaviour. Male bottlenose dolphins form long-lasting, multi-level, cooperative alliances in which they engage in coordinated efforts to coerce single oestrus females. Previous work has revealed the importance of motor synchrony in dolphin alliance behaviour. Here, we demonstrate that allied dolphins also engage in acoustic coordination whereby males will actively match the tempo and, in some cases, synchronize the production of their threat vocalization when coercing females. This finding demonstrates that male dolphins are capable of acoustic coordination in a cooperative context and, moreover, suggests that both motor and acoustic coordination are features of coalitionary behaviour that are not limited to humans.
Interleukin-2 (IL-2) is a cytokine required for effector T cell expansion, survival, and function, especially for engineered T cells in adoptive cell immunotherapy, but its pleiotropy leads to ...simultaneous stimulation and suppression of immune responses as well as systemic toxicity, limiting its therapeutic use. We engineered IL-2 cytokine-receptor orthogonal (
) pairs that interact with one another, transmitting native IL-2 signals, but do not interact with their natural cytokine and receptor counterparts. Introduction of
IL-2Rβ into T cells enabled the selective cellular targeting of
IL-2 to engineered CD4
and CD8
T cells in vitro and in vivo, with limited off-target effects and negligible toxicity.
IL-2 pairs were efficacious in a preclinical mouse cancer model of adoptive cell therapy and may therefore represent a synthetic approach to achieving selective potentiation of engineered cells.
Over the years, vocal matching has progressed beyond being an interesting behavioural phenomenon to one that now has relevance to a wide range of fields. In this review, we use birds and cetaceans to ...explain what vocal matching is, why animals vocally match and how vocal matching can be identified. We show that while the functional aspects of vocal matching are similar, the contexts in which matching is used can differ between taxa. Whereas vocal matching in songbirds facilitates mate attraction and the immediate defence of resources, in parrots and cetaceans it plays a role in the maintenance of social bonds and the promotion of behavioural synchrony. We propose criteria for defining vocal matching with the aim of stimulating more matching studies across a wider range of taxa, including those using other, non-vocal, communication modalities. Finally, we encourage future studies to explore the importance of vocal learning in the development of vocal matching, and the information it may provide to third parties in the communication network.
Social and vocal complexity in bottlenose dolphins King, Stephanie L.; Connor, Richard C.; Montgomery, Stephen H.
Trends in neurosciences (Regular ed.),
December 2022, 2022-12-00, 20221201, Letnik:
45, Številka:
12
Journal Article
Recenzirano
Odprti dostop
Bottlenose dolphins are highly social, renowned for their vocal flexibility, and possess highly enlarged brains relative to their body size. Here, we discuss some of the defining features of ...bottlenose dolphin social and vocal complexity and place this in the context of their cognitive evolution.
Vocal learning is relatively common in birds but less so in mammals. Sexual selection and individual or group recognition have been identified as major forces in its evolution. While important in the ...development of vocal displays, vocal learning also allows signal copying in social interactions. Such copying can function in addressing or labelling selected conspecifics. Most examples of addressing in non-humans come from bird song, where matching occurs in an aggressive context. However, in other animals, addressing with learned signals is very much an affiliative signal. We studied the function of vocal copying in a mammal that shows vocal learning as well as complex cognitive and social behaviour, the bottlenose dolphin (Tursiops truncatus). Copying occurred almost exclusively between close associates such as mother–calf pairs and male alliances during separation and was not followed by aggression. All copies were clearly recognizable as such because copiers consistently modified some acoustic parameters of a signal when copying it. We found no evidence for the use of copying in aggression or deception. This use of vocal copying is similar to its use in human language, where the maintenance of social bonds appears to be more important than the immediate defence of resources.
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