Ey, Elodie

[["dc.bibliographiccitation.firstpage","947"],["dc.bibliographiccitation.issue","4"],["dc.bibliographiccitation.journal","International Journal of Primatology"],["dc.bibliographiccitation.lastpage","960"],["dc.bibliographiccitation.volume","28"],["dc.contributor.author","Ey, Elodie"],["dc.contributor.author","Hammerschmidt, Kurt"],["dc.contributor.author","Seyfarth, Robert M."],["dc.contributor.author","Fischer, Julia"],["dc.date.accessioned","2018-03-08T09:22:21Z"],["dc.date.available","2018-03-08T09:22:21Z"],["dc.date.issued","2007"],["dc.description.abstract","Changes in vocalizations during ontogeny can in principle be related to three factors: growth, maturation, and experience, i.e., learning. While learning is a prerequisite for the proper development of speech, it hardly appears to play a role in the development of the species-typical vocal behavior of nonhuman primates. Nonetheless, subjects of different age and sex often exhibit prominent variation in the structure of their vocalizations. We investigated ontogenetic changes and the emergence of sex-related differences in the acoustic structure of Chacma baboon (Papio ursinus) clear calls. We recorded the vocalizations emitted by individuals separated from the rest of the group or from particular individuals, in a group of baboons in the Moremi Wildlife Reserve, Botswana. We analyzed calls from 58 baboons of both sexes and all age classes. While the structure of the call appeared to be fixed from birth, call duration, the distribution of energy, and the fundamental frequency of the calls, including modulation, varied with age and sex of the caller. We discuss how body size may explain the variations. Some of the variables exhibited a different profile of variation with age between the sexes, with significant differences becoming apparent around puberty. The emergence of these sexual differences may be explained by the onset of sexual dimorphism in body size and mass. To which degree the hormonal status contributes to variation in the calling remains to be investigated."],["dc.identifier.doi","10.1007/s10764-007-9139-3"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/12957"],["dc.language.iso","en"],["dc.notes.intern","GRO-Li-Import"],["dc.notes.status","final"],["dc.relation.doi","10.1007/s10764-007-9139-3"],["dc.relation.eissn","1573-8604"],["dc.relation.issn","0164-0291"],["dc.relation.issn","1573-8604"],["dc.title","Age- and Sex-Related Variations in Clear Calls of Papio ursinus"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","493"],["dc.bibliographiccitation.issue","5"],["dc.bibliographiccitation.journal","Ethology"],["dc.bibliographiccitation.lastpage","503"],["dc.bibliographiccitation.volume","115"],["dc.contributor.author","Ey, Elodie"],["dc.contributor.author","Rahn, Charlotte"],["dc.contributor.author","Hammerschmidt, Kurt"],["dc.contributor.author","Fischer, Julia"],["dc.date.accessioned","2017-09-07T11:47:13Z"],["dc.date.available","2017-09-07T11:47:13Z"],["dc.date.issued","2009"],["dc.description.abstract","Sound propagates differently and visibility varies according to the habitat type. Animals should therefore adapt the acoustic structure and the usage of their vocal signals to the environment. In the present study, we examined the influence of the habitat on the vocal behaviour of wild olive baboons (Papio hamadryas anubis) in two populations: one living in Gashaka-Gumti National Park, Nigeria, and the other in Budongo Forest, Uganda. We investigated whether female baboons modified the acoustic structure of their grunts and their rate of grunting when they wandered between closed and open habitat types. As an adaptation to the environmental conditions, baboons might utter calls with a longer duration, a lower fundamental frequency and/or energy concentrated in lower frequencies in a closed habitat like forest than in an open habitat. Baboons should also grunt more frequently in the closed habitat. Analyses showed that in both populations grunts uttered in forest were significantly longer than in open habitat. Additionally, baboons from Uganda showed a significantly higher grunt rate in forest than in open habitat. These results revealed a certain degree of plasticity in vocal production and call usage with regard to the habitat type. However, results in Nigeria suggested that, besides habitat structure, other proximate factors like the context of calling and the proximity between group members could also have an influence on the actual communication patterns."],["dc.identifier.doi","10.1111/j.1439-0310.2009.01638.x"],["dc.identifier.gro","3150653"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/7433"],["dc.language.iso","en"],["dc.notes.status","final"],["dc.relation.issn","0179-1613"],["dc.title","Wild Female Olive Baboons Adapt their Grunt Vocalizations to Environmental Conditions"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dc.type.peerReviewed","no"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","413"],["dc.bibliographiccitation.lastpage","436"],["dc.bibliographiccitation.volume","35"],["dc.contributor.author","Ey, Elodie"],["dc.contributor.author","Fischer, Julia"],["dc.contributor.editor","Sommer, Volker"],["dc.contributor.editor","Ross, Caroline"],["dc.date.accessioned","2017-09-07T11:47:15Z"],["dc.date.available","2017-09-07T11:47:15Z"],["dc.date.issued","2011"],["dc.description.abstract","Vocal production learning, and in particular the ability to imitate other people’s vocalisations, is a key foundation of human speech. From an evolutionary perspective, it is puzzling that our closest living relatives, monkeys and apes, show so little flexibility in terms of altering the structure of their vocalisations. Instead, non-human primates typically have a restricted vocal repertoire consisting of different call types with varying degrees of variability within and between types. This raises two questions: first, which factors affect the overall morphology of vocal repertoires, and second, within the rather fixed system of a given vocal repertoire, which aspects of vocal production may reveal a certain degree of plasticity. Baboons lend themselves for an investigation of these questions because they show a high degree of flexibility with respect to social structure and habitats they range in. Moreover, their phylogenetic relatedness is well understood. In this study, we investigated whether olive baboons from two troops ranging in Gashaka Gumti National Park / Nigeria, adjust their calls in relation to the habitat. We compare the results to findings from other sites (olive baboons from Uganda, chacma baboons from Botswana), to explore variation within and between populations. We focus on contact calls used over short distances (grunts) and long distances (clear barks) and tested whether usage (grunt and bark rates) and call structure differed in relation to the habitat. We expected a larger degree of flexibility in call usage compared to variation in call structure and predicted that subjects would call more frequently when the visibility is poor. If individuals are in fact able to modify the structure of their calls, theory predicts that they should optimise the propagation distance by using longer calls in forest compared to woodland-savannah, with a lower ­frequency and energy concentrated in lower frequencies. Indeed, the baboons uttered significantly longer grunts in forest than in open woodland, suggesting some degree of intra-individual short-term flexibility. Contrary to our expectations, grunt usage did not vary with the habitat type, perhaps because a large proportion were used in social contexts, during infant handling and friendly approaches. Since these calls are given at close range, visibility was not affected. Our observation also showed little variation in grunt rate between the troops. However, compared to some other populations and taxa, Nigerian baboons grunted rarely, so that the lack of variation in relation to habitat may simply reflect a floor effect. Clear barks were given mostly as single calls by immature individuals and adult females when separated from the group or particular group members, while resting alone and travelling. Bark rate varied between troops, but not in relation to habitat type. Due to small sample size, bark structure was not analysed. Overall, our findings highlight similarities between baboon taxa in call contexts, as well as variation in responses to changing environmental conditions. Probably, other factors than the environment – such as interaction rates, for instance – may affect call usage. Future studies will need to integrate data from multiple baboon taxa to establish a better picture of the interplay between different factors that govern variation in call usage and structure."],["dc.identifier.doi","10.1007/978-1-4419-7403-7_10"],["dc.identifier.gro","3150663"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/7444"],["dc.language.iso","en"],["dc.notes.status","final"],["dc.notes.submitter","chake"],["dc.publisher","Springer"],["dc.publisher.place","New York"],["dc.relation.crisseries","Developments in Primatology"],["dc.relation.isbn","978-1-4419-7402-0"],["dc.relation.ispartof","Primates of Gashaka"],["dc.relation.ispartofseries","Developments in Primatology: Progress and Prospects;"],["dc.title","Keeping in Contact: Flexibility in Calls of Olive Baboons"],["dc.type","book_chapter"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","no"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","253"],["dc.bibliographiccitation.issue","4"],["dc.bibliographiccitation.journal","Primates"],["dc.bibliographiccitation.lastpage","267"],["dc.bibliographiccitation.volume","48"],["dc.contributor.author","Ey, Elodie"],["dc.contributor.author","Pfefferle, Dana"],["dc.contributor.author","Fischer, Julia"],["dc.date.accessioned","2018-03-08T09:22:20Z"],["dc.date.available","2018-03-08T09:22:20Z"],["dc.date.issued","2007"],["dc.description.abstract","In vocal communication, the mechanisms of sound production are well understood. The length of the vocal folds determines the minimum fundamental frequency, while the size and the shape of the vocal tract affect its filtering characteristics and hence, the resonant frequencies. Both measures—vocal fold length and vocal tract length—are related to body size and therefore, acoustic features are expected to vary with body size. Because direct measures of body size are difficult to obtain from free-ranging animals, age and sex have often been used as proxies. We surveyed studies which included direct measures of size or weight, and also studies in which only age and/or sex differences were examined. The main purpose was to examine whether age- and sex-related variations in acoustic features meet the predictions generated from our knowledge about sound production. Our survey revealed that compared to smaller animals, larger animals utter longer calls, with a lower fundamental frequency, with smaller formant dispersion, and with the energy concentrated in lower frequencies. Age and sex reliably reflect the influence of body size on acoustic features when gross size differences are examined. However, within age- and sex classes, this relationship may break down. In addition to body size, other factors such as internal state or social context may also influence the structure of vocal signals and highlight the richness of information in calls that is potentially available to listeners."],["dc.identifier.doi","10.1007/s10329-006-0033-y"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/12951"],["dc.language.iso","en"],["dc.notes.intern","GRO-Li-Import"],["dc.notes.status","final"],["dc.relation.doi","10.1007/s10329-006-0033-y"],["dc.relation.eissn","1610-7365"],["dc.relation.issn","0032-8332"],["dc.relation.issn","1610-7365"],["dc.title","Do age- and sex-related variations reliably reflect body size in non-human primate vocalizations? A review"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","21"],["dc.bibliographiccitation.issue","1-2"],["dc.bibliographiccitation.journal","Bioacoustics"],["dc.bibliographiccitation.lastpage","48"],["dc.bibliographiccitation.volume","19"],["dc.contributor.author","Ey, Elodie"],["dc.contributor.author","Fischer, J."],["dc.date.accessioned","2017-09-07T11:47:42Z"],["dc.date.available","2017-09-07T11:47:42Z"],["dc.date.issued","2009"],["dc.description.abstract","The acoustic properties of the environment influence sound propagation. Many previous studies examined whether various species of anurans, birds and mammals adjust usage and/or structure of their vocal signals to limit degradation during propagation in this environment (“acoustic adaptation hypothesis”). The present review examines how widespread such adaptations actually are across taxa. First, evidence for environment-related adjustments in usage of vocal signals is collected from studies in birds and other vertebrates (i.e., anurans and mammals). Second, a meta-analysis conducted by Boncoraglio & Saino (2007) on the influences of the environment on the acoustic structure of avian vocalisations is taken as a reference, and results from additional studies in birds are reviewed and compared to its conclusions. Finally, evidence from similar studies conducted in anurans and mammals is collected and discussed. Concerning the usage of vocal signals, evidence of environment-related adaptations in the few studies found was more widespread in anurans and mammals than in birds. Regarding structure of vocal signals, evidence from additional studies in birds did not completely confirm results of the meta-analysis of Boncoraglio & Saino (2007). Pooling all bird studies together presented minimum frequency, frequency modulations and frequency range as acoustic variables most often adjusted to the environment, in contrast to temporal features, repetition rate and maximum frequency. The few studies conducted in anurans and mammals did not allow the identification of specific acoustic variables that typically show environment-related variations. Overall, evidence for the acoustic adaptation hypothesis was not as widespread as expected across taxa. The different aspects of vocal behaviour adapted to environmental conditions varied according to the species and local habitats. Environment-related adjustments in structure of vocal signals seem to be constrained by call function in anurans and mammals. This effect was not examined in birds, but vocal learning does not appear to be a pre-requisite to environment-related adjustment in this group."],["dc.identifier.doi","10.1080/09524622.2009.9753613"],["dc.identifier.gro","3150687"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/7471"],["dc.language.iso","en"],["dc.notes.status","final"],["dc.relation.issn","0952-4622"],["dc.title","The “Acoustic Adaption Hypothetis”—A Review of the Evidence from Birds, Anurans and Mammals"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dc.type.peerReviewed","yes"],["dspace.entity.type","Publication"]]