@article {53363, title = {Advertising individual identity by mother and adolescent contact calls in Siberian wapiti Cervus elaphus sibiricus}, journal = {Ethology}, volume = {124}, year = {2018}, month = {Jan-10-2018}, pages = {733 - 742}, abstract = {

Individualistic contact calls facilitate mother-offspring reunion after separation. However, in many mammals, both the acoustic structure and individuality of contact calls differ between mother and young. In contrast, in Siberian wapiti Cervus elaphus sibiricus, contact calls are similar in the acoustics between mother and young, whereas effects of this similarity on vocal individuality were not investigated. In this study, we analyzed acoustic differences between closed-mouth (nasal) and open-mouth (oral) contact calls and examined individuality of the most usual oral calls of 19 Siberian wapiti (9 hinds and 10 5\–6-month adolescents) emitted in response to mother-offspring separation. In the oral calls, the values of frequency and power variables were higher than in the nasal calls. Calls of hinds and adolescents did not differ by the maximum fundamental frequency and duration, whereas the peak frequency was higher in the young. Discriminant function analysis (DFA) based on 11 acoustic variables of oral calls accurately classified to individual 92.5\% of hind calls and 96.9\% of adolescent calls (chi-square test for differences between hinds and adolescents, p = 0.19). Variables mainly contributing to vocal identity (duration, start, and maximum fundamental frequency) were the same in calls of mothers and adolescents. We conclude that similarities in the acoustics calls of mothers and adolescents mean that they do not differ in their potential for encoding individual identity, suggesting a mutual process of mother-offspring vocal recognition in Siberian wapiti.

}, doi = {10.1111/eth.2018.124.issue-1010.1111/eth.12804}, url = {http://doi.wiley.com/10.1111/eth.2018.124.issue-10}, author = {Sibiryakova, Olga V. and Volodin, Ilya A. and Volodina, Elena V.}, editor = {Wright, J.} } @article {52565, title = {Bottlenose dolphins that forage with artisanal fishermen whistle differently}, journal = {Ethology}, volume = {123}, year = {2017}, month = {Jan-12-2017}, pages = {906 - 915}, abstract = {

Acoustic communication is a taxonomically widespread phenomenon, crucial for social animals. We evaluate social sounds from bottlenose dolphins (Tursiops truncatus) of Laguna, southern Brazil, whose social structure is organized around a cooperative foraging tactic with artisanal fishermen. This tactic involves stereotyped and coordinated behaviour by dolphins and fishermen and is performed by a subset of the dolphin population, splitting it into two distinct social communities. We compared the acoustic parameters and type of whistles emitted by dolphins of the \“non-cooperative\” and \“cooperative\” communities, both during their interactions with fishermen and in times where dolphins were engaged in other types of foraging. Our findings show how dolphins\’ social sounds differ between foraging tactics and social communities. The frequencies of six whistle types (ascending, descending, concave, convex, multiple, flat) were significantly dependent on tactics and communities. Ascending whistles were more common than expected during foraging without fishermen, and among dolphins of the non-cooperative community. Whistle acoustic parameters (duration, number of inclination changes and inflection points, and initial, final, maximum, minimum frequencies) also varied between social communities. In general, whistles emitted by cooperative dolphins, mainly when not interacting with fishermen, tended to be shorter, had higher frequency and more inflections than those emitted by non-cooperative dolphins. These results suggest that different whistles may convey specific information among dolphins related to foraging, which we hypothesize promote social cohesion among members of the same social community. These differences in acoustic repertoires add a new dimension of complexity to this unique human\–animal interaction.

}, doi = {10.1111/eth.2017.123.issue-1210.1111/eth.12665}, url = {http://doi.wiley.com/10.1111/eth.2017.123.issue-12}, author = {Romeu, Bianca and Cantor, Mauricio and Bezamat, Carolina and Sim{\~o}es-Lopes, Paulo C. and Daura-Jorge, F{\'a}bio G.}, editor = {Ebensperger, L.} } @article {50505, title = {Individuality of distress and discomfort calls in neonates with bass voices: Wild-living goitred gazelles ( Gazella subgutturosa) and saiga antelopes ( Saiga tatarica)}, journal = {Ethology}, volume = {123}, year = {2017}, month = {Jan-05-2017}, pages = {386 - 396}, abstract = {

Neonate ruminants produce distress calls when captured by a predator and discomfort milk begging calls when hungry. In many neonate ruminants, the distress and discomfort calls are high-frequency vocalizations, in which the fundamental frequency is the key variable for recognition of their emotional arousal by caregivers. In contrast, in this study, we examine the low-frequency open-mouth distress and discomfort calls in the neonates of two species of wild-living ungulates, which clearly highlight vocal tract resonances (formants). In the goitred gazelle (Gazella subgutturosa), the distress calls were higher in fundamental frequency (f0) and in the first and third formants than the discomfort calls. The accuracy of classifying individuals by variables of distress calls with discriminant function analysis (67\%) was significantly lower than that of discomfort calls (85\%). In the saiga (Saiga tatarica), only the third formant was higher in the distress calls than in the discomfort calls. The accuracy of classifying individuals by variables of distress calls (89\%) did not differ significantly from that of discomfort calls (94\%). Thus, the use of acoustic cues to vocal identity and to the degree of arousal differs between the two species. Calls were significantly more individualistic in the saiga, probably because this species lives in large herds and neonates use a \‘following\’ antipredatory strategy, in which vocal individuality is crucial for mother\–offspring communication. In contrast, goitred gazelles live in smaller groups and neonates use a \‘hiding\’ antipredatory strategy. Accordingly, mothers can rely on additional environmental cues for spotting their young and this may decrease the necessity for individualization of the calls of neonates.

}, keywords = {acoustic behavior, antipredatory strategy, emotional arousal, mother-offspring communication, ruminants, vocal identity}, doi = {10.1111/eth.2017.123.issue-510.1111/eth.12607}, url = {http://doi.wiley.com/10.1111/eth.2017.123.issue-5}, author = {Volodin, Ilya A. and Sibiryakova, Olga V. and Frey, Roland and Efremova, Kseniya O. and Soldatova, Natalia V. and Zuther, Steffen and Kisebaev, Talgat B. and Salemgareev, Albert R. and Volodina, Elena V.} }