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Vincent M Janik - One of the best experts on this subject based on the ideXlab platform.
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Communication in bottlenose dolphins: 50 years of signature whistle research
Journal of Comparative Physiology A, 2013Co-Authors: Vincent M Janik, Laela S. SayighAbstract:Bottlenose dolphins ( Tursiops truncatus ) produce individually distinctive signature whistles that broadcast the identity of the caller. Unlike voice cues that affect all calls of an animal, signature whistles are distinct whistle types carrying identity information in their frequency modulation pattern. Signature whistle development is influenced by vocal production learning. Animals use a whistle from their environment as a model, but modify it, and thus invent a novel signal. Dolphins also copy signature whistles of others, effectively addressing the whistle owner. This copying occurs at low rates and the resulting copies are recognizable as such by parameter variations in the copy. Captive dolphins can learn to associate novel whistles with objects and use these whistles to report on the presence or absence of the object. If applied to signature whistles, this ability would make the signature whistle a rare example of a learned referential signal in animals. Here, we review the history of signature whistle research, covering definitions, acoustic features, information content, contextual use, developmental aspects, and species comparisons with mammals and birds. We show how these signals stand out amongst recognition calls in animals and how they contribute to our understanding of complexity in animal communication.
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Communication in bottlenose dolphins: 50 years of signature whistle research
Journal of Comparative Physiology A: Neuroethology Sensory Neural and Behavioral Physiology, 2013Co-Authors: Vincent M Janik, Laela S. SayighAbstract:Bottlenose dolphins (Tursiops truncatus) produce individually distinctive signature whistles that broadcast the identity of the caller. Unlike voice cues that affect all calls of an animal, signature whistles are distinct whistle types carrying identity information in their frequency modulation pattern. Signature whistle development is influenced by vocal production learning. Animals use a whistle from their environment as a model, but modify it, and thus invent a novel signal. Dolphins also copy signature whistles of others, effectively addressing the whistle owner. This copying occurs at low rates and the resulting copies are recognizable as such by parameter variations in the copy. Captive dolphins can learn to associate novel whistles with objects and use these whistles to report on the presence or absence of the object. If applied to signature whistles, this ability would make the signature whistle a rare example of a learned referential signal in animals. Here, we review the history of signature whistle research, covering definitions, acoustic features, information content, contextual use, developmental aspects, and species comparisons with mammals and birds. We show how these signals stand out amongst recognition calls in animals and how they contribute to our understanding of complexity in animal communication.
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Context-specific use suggests that bottlenose dolphin signature whistles are cohesion calls
Animal Behaviour, 1998Co-Authors: Vincent M Janik, Peter J.b. SlaterAbstract:Studies on captive bottlenose dolphins, Tursiops truncatus, have shown that each individual produces a stereotyped, individually specific signature whistle; however, no study has demonstrated clear context-dependent usage of these whistles. Thus, the hypothesis that signature whistles are used to maintain group cohesion remains untested. To investigate whether signature whistles are used only in contexts that would require a mechanism to maintain group cohesion, we examined whistle type usage in a group of four captive bottlenose dolphins in two contexts. Individuals were recorded while they were separate from the group and while they all swam in the same pool. Separations occurred spontaneously when one animal swam into another pool. No partitions were used and no aggressive interactions between dolphins preceded separations. Calling animals were identified by an amplitude comparison of the same sound recorded in the two pools. Each dolphin primarily produced one stereotyped signature whistle when it was separated from the group. Similarly the remaining group in the other pool also used primarily their signature whistles if one animal was in a separate pool. If all animals swam in the same pool almost only nonsignature whistles were used. Signature whistle copying was rare and did not initiate reunions or specific vocal responses. The results strongly support the hypothesis that signature whistles are used to maintain group cohesion.
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Whistle matching in wild bottlenose dolphins
The Journal of the Acoustical Society of America, 1997Co-Authors: Vincent M JanikAbstract:Bottlenose dolphins (Tursiops truncatus) produce individually distinctive signature whistles when they are in isolation. These whistles have been hypothesized to be important in individual recognition and group cohesion. However, captive individuals are known sometimes to imitate each other’s signature whistles. Imitation could either lead to confusion over the caller’s identity and act against individual recognition or could be used to address specific individuals in a communication network. In this study a hydrophone array with three transducers was used to investigate whether whistle copying also occurs in the wild. Recordings were made in a 500‐ m‐wide channel in the Moray Firth, Scotland. Caller position was determined by comparing differences in the time of arrival of a sound at different hydrophones. Since signature whistles could not be determined by isolating individuals, exact whistle matching in vocal interactions was used to study copying. The results showed that whistle matching occurred in 17% of all whistle interactions. An analysis of the variability of matched whistles showed similar degrees of stereotypy as reported for signature whistles. Thus signature whistle matching seems to be an important feature of bottlenose dolphin communication in the wild. [This study was funded by a DAAD‐Doktorandenstipendium HSPII/AUFE.]
Laela S. Sayigh - One of the best experts on this subject based on the ideXlab platform.
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Communication in bottlenose dolphins: 50 years of signature whistle research
Journal of Comparative Physiology A, 2013Co-Authors: Vincent M Janik, Laela S. SayighAbstract:Bottlenose dolphins ( Tursiops truncatus ) produce individually distinctive signature whistles that broadcast the identity of the caller. Unlike voice cues that affect all calls of an animal, signature whistles are distinct whistle types carrying identity information in their frequency modulation pattern. Signature whistle development is influenced by vocal production learning. Animals use a whistle from their environment as a model, but modify it, and thus invent a novel signal. Dolphins also copy signature whistles of others, effectively addressing the whistle owner. This copying occurs at low rates and the resulting copies are recognizable as such by parameter variations in the copy. Captive dolphins can learn to associate novel whistles with objects and use these whistles to report on the presence or absence of the object. If applied to signature whistles, this ability would make the signature whistle a rare example of a learned referential signal in animals. Here, we review the history of signature whistle research, covering definitions, acoustic features, information content, contextual use, developmental aspects, and species comparisons with mammals and birds. We show how these signals stand out amongst recognition calls in animals and how they contribute to our understanding of complexity in animal communication.
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Communication in bottlenose dolphins: 50 years of signature whistle research
Journal of Comparative Physiology A: Neuroethology Sensory Neural and Behavioral Physiology, 2013Co-Authors: Vincent M Janik, Laela S. SayighAbstract:Bottlenose dolphins (Tursiops truncatus) produce individually distinctive signature whistles that broadcast the identity of the caller. Unlike voice cues that affect all calls of an animal, signature whistles are distinct whistle types carrying identity information in their frequency modulation pattern. Signature whistle development is influenced by vocal production learning. Animals use a whistle from their environment as a model, but modify it, and thus invent a novel signal. Dolphins also copy signature whistles of others, effectively addressing the whistle owner. This copying occurs at low rates and the resulting copies are recognizable as such by parameter variations in the copy. Captive dolphins can learn to associate novel whistles with objects and use these whistles to report on the presence or absence of the object. If applied to signature whistles, this ability would make the signature whistle a rare example of a learned referential signal in animals. Here, we review the history of signature whistle research, covering definitions, acoustic features, information content, contextual use, developmental aspects, and species comparisons with mammals and birds. We show how these signals stand out amongst recognition calls in animals and how they contribute to our understanding of complexity in animal communication.
Volker B Deecke - One of the best experts on this subject based on the ideXlab platform.
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Whistle communication in mammal-eating killer whales (Orcinus orca): Further evidence for acoustic divergence between ecotypes
Behavioral Ecology and Sociobiology, 2011Co-Authors: Rüdiger Riesch, Volker B DeeckeAbstract:Public signaling plays an important role in territorial and sexual displays in animals; however, in certain situations, it is advantageous to keep signaling private to prevent eavesdropping by unintended receivers. In the northeastern Pacific, two populations of killer whales (Orcinus orca), fish-eating " resident " killer whales and mammal-eating " transient " killer whales, share the same habitat. Previous studies have shown that residents use whistles as private signals during close-range communica-tion, where they probably serve to coordinate behavioral interactions. Here, we investigated the whistling behavior of mammal-eating killer whales, and, based on divergent social structures and social behaviors between residents and transients, we predicted to find differences in both whistle usage and whistle parameters. Our results show that, like resident killer whales, transients produce both variable and stereotyped whistles. However, clear differences in whistle parameters between ecotypes show that the whistle reper-toire of mammal-eating killer whales is clearly distinct from and less complex than that of fish-eating killer whales. Furthermore, mammal-eating killer whales only produce whistles during " milling after kill " and " surface-active " behaviors, but are almost completely silent during all other activities. Nonetheless, whistles of transient killer whales may still serve a role similar to that of resident killer whales. Mammal-eating killer whales seem to be under strong selection to keep their communication private from potential prey (whose hearing ranges overlap with that of killer whales), and they appear to accomplish this mainly by restricting vocal activity rather than by changes in whistle parameters.
Rüdiger Riesch - One of the best experts on this subject based on the ideXlab platform.
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Whistle communication in mammal-eating killer whales (Orcinus orca): Further evidence for acoustic divergence between ecotypes
Behavioral Ecology and Sociobiology, 2011Co-Authors: Rüdiger Riesch, Volker B DeeckeAbstract:Public signaling plays an important role in territorial and sexual displays in animals; however, in certain situations, it is advantageous to keep signaling private to prevent eavesdropping by unintended receivers. In the northeastern Pacific, two populations of killer whales (Orcinus orca), fish-eating " resident " killer whales and mammal-eating " transient " killer whales, share the same habitat. Previous studies have shown that residents use whistles as private signals during close-range communica-tion, where they probably serve to coordinate behavioral interactions. Here, we investigated the whistling behavior of mammal-eating killer whales, and, based on divergent social structures and social behaviors between residents and transients, we predicted to find differences in both whistle usage and whistle parameters. Our results show that, like resident killer whales, transients produce both variable and stereotyped whistles. However, clear differences in whistle parameters between ecotypes show that the whistle reper-toire of mammal-eating killer whales is clearly distinct from and less complex than that of fish-eating killer whales. Furthermore, mammal-eating killer whales only produce whistles during " milling after kill " and " surface-active " behaviors, but are almost completely silent during all other activities. Nonetheless, whistles of transient killer whales may still serve a role similar to that of resident killer whales. Mammal-eating killer whales seem to be under strong selection to keep their communication private from potential prey (whose hearing ranges overlap with that of killer whales), and they appear to accomplish this mainly by restricting vocal activity rather than by changes in whistle parameters.
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Whistle sequences in wild killer whales (Orcinus orca)
Journal of the Acoustical Society of America, 2008Co-Authors: Rüdiger Riesch, John K. B. Ford, Frank ThomsenAbstract:Combining different stereotyped vocal signals into specific sequences increases the range of information that can be transferred between individuals. The temporal emission pattern and the behavioral context of vocal sequences have been described in detail for a variety of birds and mammals. Yet, in cetaceans, the study of vocal sequences is just in its infancy. Here, we provide a detailed analysis of sequences of stereotyped whistles in killer whales off Vancouver Island, British Columbia. A total of 1140 whistle transitions in 192 whistle sequences recorded from resident killer whales were analyzed using common spectrographic analysis techniques. In addition to the stereotyped whistles described by Riesch et al., [(2006). “Stability and group specificity of stereotyped whistles in resident killer whales, Orcinus orca, off British Columbia,” Anim. Behav. 71, 79–91.] We found a new and rare stereotyped whistle (W7) as well as two whistle elements, which are closely linked to whistle sequences: (1) stammers...
Peter L Tyack - One of the best experts on this subject based on the ideXlab platform.
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Postpartum whistle production in bottlenose dolphins
Marine Mammal Science, 2008Co-Authors: Deborah Fripp, Peter L TyackAbstract:Despite much research on bottlenose dolphin signature whistles, few have in- vestigated the role of maternal whistles in early calf development.We investigated maternal whistle use in the first weeks postpartum for captive dolphins. The over- all whistling rate increased by a factor of ten when the calves were born and then decreased again in the third week of the one surviving calf. Adult whistles were distinguished from calf whistles based on the extent of frequency modulation and were further classified into signature and non-signature whistles by comparison to a dictionary of known whistles. The average rate of maternal signature whistle pro- duction increased significantly from 0.02 whistles per dolphin-minute before the calves were born to 0.2 and 0.3 whistles in weeks 1 and 2, decreasing again to 0.06 in week 3 for the mother of the surviving calf. Percent maternal signature whistles changed similarly. Signature whistle production by non-mothers did not change when the calves were born. A likely function of this increase in maternal signature whistle production is that it enables the calf to learn to identify the mother in the first weeks of life.
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captive dolphins tursiops truncatus develop signature whistles that match acoustic features of human made model sounds
Journal of the Acoustical Society of America, 2002Co-Authors: Jennifer L Miksis, Peter L Tyack, John R BuckAbstract:This paper presents a cross-sectional study testing whether dolphins that are born in aquarium pools where they hear trainers' whistles develop whistles that are less frequency modulated than those of wild dolphins. Ten pairs of captive and wild dolphins were matched for age and sex. Twenty whistles were sampled from each dolphin. Several traditional acoustic features (total duration, duration minus any silent periods, etc.) were measured for each whistle, in addition to newly defined flatness parameters: total flatness ratio (percentage of whistle scored as unmodulated), and contiguous flatness ratio (duration of longest flat segment divided by total duration). The durations of wild dolphin whistles were found to be significantly longer, and the captive dolphins had whistles that were less frequency modulated and more like the trainers' whistles. Using a standard t-test, the captive dolphin had a significantly higher total flatness ratio in 9/10 matched pairs, and in 8/10 pairs the captive dolphin had significantly higher contiguous flatness ratios. These results suggest that captive-born dolphins can incorporate features of artificial acoustic models made by humans into their signature whistles.