@article {58230, title = {Bottlenose dolphin (Tursiops truncatus) calves appear to model their signature whistles on the signature whistles of community members}, year = {2005}, abstract = {

Bottlenose dolphins are unusual among non-human mammals in their ability to learn new sounds. This study investigates the importance of vocal learning in the development of dolphin signature whistles and the influence of social interactions on that process. We used focal animal behavioral follows to observe six calves in Sarasota Bay, Fla., recording their social associations during their first summer, and their signature whistles during their second. The signature whistles of five calves were determined. Using dynamic time warping (DTW) of frequency contours, the calves\’ signature whistles were compared to the signature whistles of several sets of dolphins: their own associates, the other calves\’ associates, Tampa Bay dolphins, and captive dolphins. Whistles were considered similar if their DTW similarity score was greater than those of 95\% of the whistle comparisons. Association was defined primarily in terms of time within 50 m of the mother/calf pair. On average, there were six dolphins with signature whistles similar to the signature whistles of each of the calves. These were significantly more likely to be Sarasota Bay resident dolphins than non-Sarasota dolphins, and (though not significantly) more likely to be dolphins that were within 50 m of the mother and calf less than 5\% of the time. These results suggest that calves may model their signature whistles on the signature whistles of members of their community, possibly community members with whom they associate only rarely.

}, keywords = {bottlenose dolphin, Social influences on learning, vocal learning, Whistle development}, doi = {10.1007/s10071-004-0225-z}, url = {http://link.springer.com/10.1007/s10071-004-0225-z}, author = {Fripp, Deborah and Owen, Caryn and Quintana-Rizzo, Ester and Shapiro, Ari and Buckstaff, Kara and Jankowski, Kristine and Wells, Randall and Tyack, Peter} } @article {58030, title = {Individual signatures outweigh social group identity in contact calls of a communally nesting parrot}, year = {2019}, abstract = {

Despite longstanding interest in the evolutionary origins and maintenance of vocal learning, we know relatively little about how social dynamics influence vocal learning processes in natural populations. The \“signaling group membership\” hypothesis proposes that socially learned calls evolved and are maintained as signals of group membership. However, in fission\–fusion societies, individuals can interact in social groups across various social scales. For learned calls to signal group membership over multiple social scales, they must contain information about group membership over each of these scales, a concept termed \“hierarchical mapping.\” Monk parakeets (Myiopsitta monachus), small parrots native to South America, exhibit vocal mimicry in captivity and fission\–fusion social dynamics in the wild. We examined patterns of contact call acoustic similarity in Uruguay to test the hierarchical mapping assumption of the signaling group membership hypothesis. We also asked whether geographic variation patterns matched regional dialects or geographic clines that have been documented in other vocal learning species. We used visual inspection, spectrographic cross-correlation and random forests, a machine learning approach, to evaluate contact call similarity. We compared acoustic similarity across social scales and geographic distance using Mantel tests and spatial autocorrelation. We found high similarity within individuals, and low, albeit significant, similarity within groups at the pair, flock and site social scales. Patterns of acoustic similarity over geographic distance did not match mosaic or graded patterns expected in dialectal or clinal variation. Our findings suggest that monk parakeet social interactions rely more heavily upon individual recognition than group membership at higher social scales.

}, keywords = {contact call, group membership, hierarchical mapping, individual signatures, machine learning, monk parakeet, Myiopsitta monachus, vocal learning}, doi = {10.1093/beheco/arz202}, url = {https://academic.oup.com/beheco/advance-article/doi/10.1093/beheco/arz202/5680715}, author = {Smith-Vidaurre, Grace and Araya-Salas, Marcelo and Wright, Timothy F}, editor = {Naguib, Marc} } @article {53409, title = {Age and social affinity effects on contact call interactions in free-ranging spider monkeys}, journal = {Behavioral Ecology and Sociobiology}, volume = {72}, year = {2018}, month = {Jan-12-2018}, abstract = {

Nonhuman primates\’ vocal repertoire has shown little plasticity, with immatures producing adult-like acoustic structures. Yet, the use of different call types shows a degree of socially dependent flexibility during development. In several nonhuman primate species, group members exchange contact calls respecting a set of social and temporal rules that may be learned (e.g., overlap avoidance, turn-taking, social selection of interacting partners, and call type matching). Here, we study the use of contact calls in free-living adult and immature (old and young) spider monkeys (Ateles geoffroyi). We focused our study in two contact call types of the species\’ repertoire: whinnies and high-whinnies. Our results suggest that individuals in all age classes produced both call types, with immatures producing less frequently the whinny call type. Immature individuals exchanged calls less often than adults, although their contribution increased with age. Conversely, mature individuals regulated their emissions by (1) exchanging more calls with their preferred affiliative partner and (2) matching the call type, while immatures did not. Our results show that contact call usage changes during development and suggest that adult rules might be learned. We argue that call matching is a \“conversational rule\” that young individuals acquire with apparent call-type-dependent variations during development. Our findings support the idea that social factors influence vocal development in nonhuman primates.

}, keywords = {Acoustic matching, Call exchanges, New World monkeys, vocal communication, vocal learning}, issn = {0340-5443}, doi = {10.1007/s00265-018-2615-2}, url = {http://link.springer.com/10.1007/s00265-018-2615-2}, author = {Briseno-Jaramillo, M. and Ramos-Fern{\'a}ndez, G. and Palacios-Romo, T. M. and Sosa-L{\'o}pez, J. R. and Lemasson, A.} } @article {53371, title = {Kinship and association do not explain vocal repertoire variation among individual sperm whales or social units}, journal = {Animal Behaviour}, volume = {145}, year = {2018}, month = {Jan-11-2018}, pages = {131 - 140}, abstract = {

Vocal learning often results in distinct dialects among individuals or groups, but the forces selecting for these phenomena remain unclear. Female sperm whales, Physeter macrocephalus, and their dependent offspring live in matrilineally based social units, and the units associate within sympatric clans. The clans have distinctive dialects of codas (patterns of clicks), as do, to a lesser extent, the units within clans. We examined the similarity of coda repertoires of individuals and units from the eastern Caribbean and related these to patterns of kinship and social association. Similarity in coda repertoires was not discernibly correlated with close kinship or association rates for either individuals or units (matrix correlation coefficients \<0.12 for all tests using whole repertoires and data from all units). This supports the prevailing hypothesis that these vocalizations are culturally transmitted. The lack of correlation also indicates that vocal learning may occur broadly within clans, rather than preferentially from close kin or close social associates within social units, or that biases in vocal learning at lower levels of social structure are diffused by clan-level processes, such as conformity. Finally, an absence of signals of kinship in vocalization patterns suggests that a different mechanism, perhaps familiarity through repeated association, mediates kin selection among sperm whales.

}, keywords = {dialect, kinship, matrilineal, social unit, sperm whale, vocal learning, vocalization}, issn = {00033472}, doi = {10.1016/j.anbehav.2018.09.011}, url = {https://linkinghub.elsevier.com/retrieve/pii/S0003347218302811https://api.elsevier.com/content/article/PII:S0003347218302811?httpAccept=text/xmlhttps://api.elsevier.com/content/article/PII:S0003347218302811?httpAccept=text/plain}, author = {Konrad, Christine M. and Frasier, Timothy R. and Rendell, Luke and Whitehead, Hal and Gero, Shane} } @article {53229, title = {Effects of metronomic sounds on a self-paced tapping task in budgerigars and humans}, journal = {Current Zoology}, year = {2018}, month = {Nov-10-2018}, abstract = {

The origin of rhythmic synchronisation or entrainment to a musical beat in animals have been widely discussed. Parrots are suitable animals to examine the relationship between the capability of vocal learning and spontaneous rhythmic synchronisation. In this study, budgerigars (Melopsittacus undulatus) learned to tap (peck) two keys alternately at a self-paced rate. Then, the metronomic sounds were played in the background during test sessions while the birds were performing the key pecking task, although they were not required to synchronise tap timing with the metronome. We found modest but significant effects of the metronome rhythms on the tap timing in some subjects. We also tested humans (Homo sapiens) using almost the same method. In contrast to the birds, a number of human subjects synchronised tap timing to the onset of the metronome without verbal or documented instructions. However, we failed to find an effect of the metronome on self-paced tap timing in some human subjects, although they were capable of rhythmic synchronisation. This is the first report describing the effects of metronomic sounds on self-paced tapping in non-human vocal learners. This study introduces a new method that can be used in future research comparing birds that differ in vocal learning capacities, social structure, age, sex, hormonal status, and so on as part of examinations of the evolutionary foundations of beat processing.

}, keywords = {operant conditioning, parrots, rhythm, synchronisation, vocal learning}, issn = {1674-5507}, doi = {10.1093/cz/zoy075}, url = {https://academic.oup.com/cz/advance-article/doi/10.1093/cz/zoy075/5126939}, author = {Seki, Yoshimasa and Tomyta, Kenta} }