|
| ||
|
|
||
Acoustic Features (acoustic + feature)
Selected AbstractsCross-Sectional and Longitudinal Studies of the Development of Group Differences in Acoustic Features of Coo Calls in Two Groups of Japanese MacaquesETHOLOGY, Issue 1 2006Toshiaki Tanaka Japanese macaques, Macaca fuscata, frequently utter coo calls to maintain vocal contact. Cross-sectional and longitudinal comparisons were conducted on the acoustic features of coo vocalizations of two groups of M. fuscata, Yakushima and Ohirayama groups, to explore the possibility of vocal plasticity. These two groups derive from the same local population but have been separated for more than 34 yr. The Yakushima group is non-provisioned, while the Ohirayama group is provisioned. Initially, coo calls in the two groups were compared cross-sectionally in females ranging from 0 to 18 yr. Mean values of the four variables studied (start, end, maximum, and minimum frequencies) were consistently lower in all age groups of the Ohirayama individuals compared with the Yakushima individuals. Secondly, longitudinal comparisons were conducted on individuals in the 1,4 yr after birth. Mean values of the five frequency variables studied (start, end, maximum, minimum and average frequencies) were again consistently lower in all age groups of Ohirayama compared with Yakushima individuals, although mean values of both groups gradually declined with an increase in age. Inter-group differences were significant at all ages in minimum frequency and at the first, second and third years in start frequency. Longitudinal comparisons of individuals aged 4,11 mo were also conducted. Regarding the four variables that differed between the two groups in the cross-sectional study, the mean values of minimum and start frequency did not differ significantly between the two groups at 4,5 mo, but were significantly lower in Ohirayama individuals aged 7,8 and 9,11 mo. Although provisioning may have had an effect on the weight difference between the groups, and consequently on vocalization frequency, these results suggest that the inter-group differences in coo call features form approximately 6,7 mo after birth as a result of vocal plasticity. [source] Acoustic Features of Female Chacma Baboon BarksETHOLOGY, Issue 1 2001Julia Fischer We studied variation in the loud barks of free-ranging female chacma baboons (Papio cynocephalus ursinus) with respect to context, predator type, and individuality over an 18-month period in the Moremi Game Reserve, Botswana. To examine acoustic differences in relation to these variables, we extracted a suite of acoustic parameters from digitized calls and applied discriminant function analyses. The barks constitute a graded continuum, ranging from a tonal, harmonically rich call into a call with a more noisy, harsh structure. Tonal barks are typically given when the signaler is at risk of losing contact with the group or when a mother and infant have become separated (contact barks). The harsher variants are given in response to large predators (alarm barks). However, there are also intermediate forms between the two subtypes which may occur in both situations. This finding is not due to an overlap of individuals' distinct distributions but can be replicated within individuals. Within the alarm bark category, there are significant differences between calls given in response to mammalian carnivores and those given in response to crocodiles. Again, there are intermediate variants. Both alarm call types are equally different from contact barks, indicating that the calls vary along different dimensions. Finally, there are consistent, significant differences among different individuals' calls. However, individual identity in one call type cannot directly be inferred from knowledge of the individuals' call characteristics in the other. In sum, the barks of female baboons potentially provide rich information to the recipients of these signals. The extent to which baboons discriminate between alarm and contact barks, and classify calls according to context and/or acoustic similarity will be described in a subsequent paper. [source] HABITAT-DEPENDENT SONG DIVERGENCE IN THE LITTLE GREENBUL: AN ANALYSIS OF ENVIRONMENTAL SELECTION PRESSURES ON ACOUSTIC SIGNALSEVOLUTION, Issue 9 2002Hans Slabbekoorn Abstract., Bird song is a sexual trait important in mate choice and known to be shaped by environmental selection. Here we investigate the ecological factors shaping song variation across a rainforest gradient in central Africa. We show that the little greenbul (Andropadus virens), previously shown to vary morphologically across the gradient in fitness-related characters, also varies with respect to song characteristics. Acoustic features, including minimum and maximum frequency, and delivery rate of song notes showed significant differences between habitats. In contrast, we found dialectal variation independent of habitat in population-typical songtype sequences. This pattern is consistent with ongoing gene flow across habitats and in line with the view that song variation in the order in which songtypes are produced is not dependent on habitat characteristics in the same way physical song characteristics are. Sound transmission characteristics of the two habitats did not vary significantly, but analyses of ambient noise spectra revealed dramatic and consistent habitat-dependent differences. Matching between low ambient noise levels for low frequencies in the rainforest and lower minimal frequencies in greenbul songs in this habitat suggests that part of the song divergence may be driven by habitat-dependent ambient noise patterns. These results suggest that habitat-dependent selection may act simultaneously on traits of ecological importance and those important in prezygotic isolation, leading to an association between morphological and acoustic divergence. Such an association may promote assortative mating and may be a mechanism driving reproductive divergence across ecological gradients. [source] Acoustic features of infant crying related to intended caregiving interventionINFANT AND CHILD DEVELOPMENT, Issue 2 2004Debra M. ZeifmanArticle first published online: 3 JUN 200 Abstract The present study investigated the acoustic features of crying associated with intended caregiving intervention. One hundred eighty-eight parents (138 females, 50 males) viewed a videotape depicting a healthy 4-week-old infant progressing from fussing to crying over the course of 4 minutes, and indicated if and when they would pick up the infant in a real-life situation. There was a distinct peak in responding corresponding to an increase in duration but not fundamental frequency of the infant's cries. This finding is discussed in terms of the existing empirical literature. It is hypothesized that, whereas frequency may convey information about a newborn's neurological integrity and health status at birth, duration and other acoustical variables provide information about slightly older, normal infants' level of distress. Copyright © 2004 John Wiley & Sons, Ltd. [source] Voice variance may signify ongoing divergence among black-legged kittiwake populationsBIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 2 2009HERVE MULARD Acoustic features are important for individual and species recognition. However, while dialectal variations in song characteristics have been described in many songbirds, geographical divergence in vocal features across populations has seldom been studied in birds that are not thought to have song-learning abilities. Here, we document marked differences in the vocal structure of calls of two populations of black-legged kittiwakes (Rissa tridactyla), a seabird whose call is considered as not being learned from other individuals. We found that calls vary both within and between populations. Within-population variation may convey individual identity, whereas the marked differences in frequency and temporal parameters observed between the two populations may reveal ongoing divergence among kittiwake populations. Moreover, we were unable to detect any sex signature in adult calls in a Pacific population (Middleton, Alaska), while these were detected in an Atlantic population (Hornøya, Norway), potentially affecting sexual behaviours. Despite the fact that these calls seemed to change over the reproductive season and across years, the individual signature remained fairly stable. Such vocal differences suggest that Pacific and Atlantic populations may be undergoing behavioural divergences that may reveal early stages of speciation, as is suggested by molecular data. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 97, 289,297. [source] Behavioral discrimination of sexually dimorphic calls by male zebra finches requires an intact vocal motor pathwayDEVELOPMENTAL NEUROBIOLOGY, Issue 2 2001David S. Vicario Abstract Vocal communication between zebra finches includes the exchange of long calls (LCs) as well as song. By using this natural call behavior and quantifying the LCs emitted in response to playbacks of LCs of other birds, we have previously shown that adult male zebra finches have a categorical preference for the LCs of females over those of males. Female LCs are acoustically simpler than male LCs, which include complex acoustic features that are learned during development. Production of these male-typical features requires an intact nucleus RA, the sexually dimorphic source of the main telencephalic projection to brainstem vocal effectors. We have now made bilateral lesions of RA in 17 adult males and tested their discrimination behavior in the call response situation. Lesioned birds continue to call, but lose the male-typical preference for female LCs. The degree of loss is correlated with the extent of RA damage. Further, the simplified LCs of males with RA lesions have a variable duration that is correlated with stimulus features. In effect, the call response behavior of lesioned males becomes like that of females. Apparently, in the absence of RA, the remaining intact structures receive different call information than RA normally does, and/or process it differently. This suggests that the vocal motor nucleus RA could play a role in the transformation of a signal encoding the salience of stimulus parameters into a control signal that modulates the probability and strength of responding. © 2001 John Wiley & Sons, Inc. J Neurobiol 47: 109,120, 2001 [source] Cross-Sectional and Longitudinal Studies of the Development of Group Differences in Acoustic Features of Coo Calls in Two Groups of Japanese MacaquesETHOLOGY, Issue 1 2006Toshiaki Tanaka Japanese macaques, Macaca fuscata, frequently utter coo calls to maintain vocal contact. Cross-sectional and longitudinal comparisons were conducted on the acoustic features of coo vocalizations of two groups of M. fuscata, Yakushima and Ohirayama groups, to explore the possibility of vocal plasticity. These two groups derive from the same local population but have been separated for more than 34 yr. The Yakushima group is non-provisioned, while the Ohirayama group is provisioned. Initially, coo calls in the two groups were compared cross-sectionally in females ranging from 0 to 18 yr. Mean values of the four variables studied (start, end, maximum, and minimum frequencies) were consistently lower in all age groups of the Ohirayama individuals compared with the Yakushima individuals. Secondly, longitudinal comparisons were conducted on individuals in the 1,4 yr after birth. Mean values of the five frequency variables studied (start, end, maximum, minimum and average frequencies) were again consistently lower in all age groups of Ohirayama compared with Yakushima individuals, although mean values of both groups gradually declined with an increase in age. Inter-group differences were significant at all ages in minimum frequency and at the first, second and third years in start frequency. Longitudinal comparisons of individuals aged 4,11 mo were also conducted. Regarding the four variables that differed between the two groups in the cross-sectional study, the mean values of minimum and start frequency did not differ significantly between the two groups at 4,5 mo, but were significantly lower in Ohirayama individuals aged 7,8 and 9,11 mo. Although provisioning may have had an effect on the weight difference between the groups, and consequently on vocalization frequency, these results suggest that the inter-group differences in coo call features form approximately 6,7 mo after birth as a result of vocal plasticity. [source] Acoustic features of infant crying related to intended caregiving interventionINFANT AND CHILD DEVELOPMENT, Issue 2 2004Debra M. ZeifmanArticle first published online: 3 JUN 200 Abstract The present study investigated the acoustic features of crying associated with intended caregiving intervention. One hundred eighty-eight parents (138 females, 50 males) viewed a videotape depicting a healthy 4-week-old infant progressing from fussing to crying over the course of 4 minutes, and indicated if and when they would pick up the infant in a real-life situation. There was a distinct peak in responding corresponding to an increase in duration but not fundamental frequency of the infant's cries. This finding is discussed in terms of the existing empirical literature. It is hypothesized that, whereas frequency may convey information about a newborn's neurological integrity and health status at birth, duration and other acoustical variables provide information about slightly older, normal infants' level of distress. Copyright © 2004 John Wiley & Sons, Ltd. [source] Production and perception of sex differences in vocalizations of Wied's black-tufted-ear marmosets (Callithrix kuhlii)AMERICAN JOURNAL OF PRIMATOLOGY, Issue 4 2009Adam S. Smith Abstract Males and females from many species produce distinct acoustic variations of functionally identical call types. Social behavior may be primed by sex-specific variation in acoustic features of calls. We present a series of acoustic analyses and playback experiments as methods for investigating this subject. Acoustic parameters of phee calls produced by Wied's black-tufted-ear marmosets (Callithrix kuhlii) were analyzed for sex differences. Discriminant function analyses showed that calls contained sufficient acoustic variation to predict the sex of the caller. Several frequency variables differed significantly between the sexes. Natural and synthesized calls were presented to male,female pairs. Calls elicited differential behavioral responses based on the sex of the caller. Marmosets became significantly more vigilant following the playback of male phee calls (both natural and synthetic) than following female phee calls. In a second playback experiment, synthesized calls were modified by independently manipulating three parameters that were known to differ between the sexes (low-, peak-, and end-frequency). When end-frequency-modified calls were presented, responsiveness was differentiable by sex of caller but did not differ from responses to natural calls. This suggests that marmosets did not use end-frequency to determine the sex of the caller. Manipulation of peak-and low-frequency parameters eliminated the discrete behavioral responses to male and female calls. Together, these parameters may be important features that encode for the sex-specific signal. Recognition of sex by acoustic cues seems to be a multivariate process that depends on the congruency of acoustic features. Am. J. Primatol. 71:324,332, 2009. © 2008 Wiley-Liss, Inc. [source] Phylogeny and the modalities of acoustic diversification in extant Eneopterinae (Insecta, Orthoptera, Grylloidea, Eneopteridae)CLADISTICS, Issue 3 2004Tony Robillard Calling with a tegminal stridulatory apparatus is widespread in crickets. However, the evolution of cricket stridulums has been poorly studied and then only on the basis of prephylogenetic models, which are unable to account for the huge diversity recently documented for acoustic features in crickets. The present paper focuses on the evolution of acoustic devices in the subfamily Eneopterinae. This is the first attempt to reconstruct the phylogeny of a large and diverse cricket clade in order to analyze the evolution of emitting structures using precise homology statements. In the first step, we reconstruct the phylogeny of this clade using a morphological data set of 193 characters and 45 taxa. The resultant phylogeny supports the monophyly of the subfamily and that of the 13 genera represented by at least two species in our taxonomic sample. Phylogenetic relationships within the subfamily also support the definition of five tribes: Eurepini, Eneopterini, Nisitrini, Xenogryllini and Lebinthini. In the second step, the evolution of acoustic devices is studied by optimization of venation characters defined on precise homology statements. As hypothesized by previous authors, losses of acoustic communication occur independently in the course of eneopterine evolution; however, they happen abruptly with no intermediate state. Our results also document for the first time the modalities of forewing evolution: the diversification of male forewing venation originates from two processes, a continuous and regular modification process, responsible for slight venation change; and an irregular, more intense punctuated process, allowing the emergence of different venations. This diversification process with sudden changes could be related to the occurrence of acoustic novelties in advertisement calls. [source] | ||||||||||