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Call Duration (call + duration)
Selected AbstractsGeographic Variation in Male Sexual Signals in Strawberry Poison Frogs (Dendrobates pumilio)ETHOLOGY, Issue 9 2007Heike Pröhl In this paper, we compare the advertisement calls of 207 neotropical strawberry poison frogs (Dendrobates pumilio) collected in 21 localities along a transect from northern Costa Rica to western Panama. Populations varied most in call duration and call rate, while pulse rate and duty cycle were less variable. Multivariate analyses showed that call variation followed a cline with higher call rates, shorter calls, lower duty cycles and higher pulse rates in the southeast. Body size decreased towards the southeast and explained most variation in dominant frequency, as well as some residual variation in call rate. We conclude that a combination of geography and morphology is largely responsible for call variation within this species. Two inferred bio-acoustic groups were roughly in accordance with two genetic groups, geographically separated in central Costa Rica. However, genetic distances among populations did not co-vary with call dissimilarity after correction for geographic distances. Thus, differences in calls between genetic groups are probably mainly a result of clinal variation. These findings agree with the general observation that bio-acoustic variation is often not (highly) associated with genetic divergence. Moreover, colour polymorphism observed among Panamanian populations was not reflected in a higher variability in call parameters relative to the monomorphic Costa Rican populations. [source] Female Preferences for Call Traits and Male Mating Success in the Neotropical Frog Physalaemus enesefaeETHOLOGY, Issue 2 2003Zaida Tárano Female preferences for male call traits may affect male mating success and the evolution of exaggerated secondary sexual traits. We used phonotaxis experiments to examine female preferences in the frog Physalaemus enesefae in relation to variation in male call duration, dominant frequency, intercall interval and amplitude (dB SPL). Females preferred long calls, low and average dominant frequency calls, short intercall intervals and more intense calls. We compared the patterns of female preferences with those of acoustic variation among males to test the prediction that properties with low within-male variation are associated with stabilizing or weakly directional female preferences, whereas properties with high within-male variation are associated with directional preferences. Females had weakly directional preferences for the dominant frequency of the call and strongly directional preferences for call duration and call rate. We also determined whether the temporal relationship between calls influenced preferences based on the dominant frequency of the call. Preferences for low-frequency over high-frequency calls disappeared when calls partially overlapped. Females preferred the leading call regardless of its dominant frequency. We also investigated mating patterns in the field. There was size-assortative mating, as male and female body sizes snout-vent length (SVL) were positively correlated. In addition, differences in the frequency distributions of body length (SVL) between mated and unmated males approached significance; lower SVL classes were underrepresented among mated males. These patterns may reflect female preferences for lower dominant frequency calls, as there is a negative correlation between male mass and the dominant frequency of the call. [source] Changes In Rhesus Macaque ,Coo' Vocalizations during Early DevelopmentETHOLOGY, Issue 10 2000Kurt Hammerschmidt In order to test whether ,coo' calls of young rhesus macaques, Macaca mulatta, undergo some modifications during early development, and to explore which factors may influence these changes, we studied the ontogeny of their contact call, the ,coo' call. Vocalizations were recorded during brief periods of social separation. Infants were either raised with their mothers and other conspecifics, or separated from their mothers at birth and housed in a nursery with other infants. We recorded calls uttered in the separation context from 20 infants. We digitized the first 50 calls of a given series and subjected them to a Fourier transform. From each frequency,time spectrum, we extracted 65 acoustic parameters using a software program (LMA 5.9). We then used a cluster analysis to separate the ,coo' calls from other call types. With increasing age, the ,coos' dropped in pitch and became more even. The course of amplitude became more constant and the call duration increased slightly. Nevertheless, we found a high intra-individual variation throughout the 5 mo. Neither rearing condition nor sex had any apparent influence on age-related changes in ,coo' structure. With one exception, all parameters that correlated with age could be explained by variation in weight. Therefore, we conclude that growth is the main factor accounting for the observed changes. [source] The evolution of trade-offs: geographic variation in call duration and flight ability in the sand cricket, Gryllus firmusJOURNAL OF EVOLUTIONARY BIOLOGY, Issue 4 2003D. A. Roff Abstract Quantitative genetic theory assumes that trade-offs are best represented by bivariate normal distributions. This theory predicts that selection will shift the trade-off function itself and not just move the mean trait values along a fixed trade-off line, as is generally assumed in optimality models. As a consequence, quantitative genetic theory predicts that the trade-off function will vary among populations in which at least one of the component traits itself varies. This prediction is tested using the trade-off between call duration and flight capability, as indexed by the mass of the dorsolateral flight muscles, in the macropterous morph of the sand cricket. We use four different populations of crickets that vary in the proportion of macropterous males (Lab = 33%, Florida = 29%, Bermuda = 72%, South Carolina = 80%). We find, as predicted, that there is significant variation in the intercept of the trade-off function but not the slope, supporting the hypothesis that trade-off functions are better represented as bivariate normal distributions rather than single lines. We also test the prediction from a quantitative genetical model of the evolution of wing dimorphism that the mean call duration of macropterous males will increase with the percentage of macropterous males in the population. This prediction is also supported. Finally, we estimate the probability of a macropterous male attracting a female, P, as a function of the relative time spent calling (P = time spent calling by macropterous male/(total time spent calling by both micropterous and macropterous male). We find that in the Lab and Florida populations the probability of a female selecting the macropterous male is equal to P, indicating that preference is due simply to relative call duration. But in the Bermuda and South Carolina populations the probability of a female selecting a macropterous male is less than P, indicating a preference for the micropterous male even after differences in call duration are accounted for. [source] Time course of vocal modulation during isolation in common marmosets (Callithrix jacchus)AMERICAN JOURNAL OF PRIMATOLOGY, Issue 8 2010Chieko Yamaguchi Abstract Common marmosets vocalize phee calls as isolation calls, which seem to facilitate their reunion with family groups. To identify multiple acoustic properties with different time courses, we examined acoustic modulations of phees during different social contexts of isolation. Subject marmosets were totally isolated in one condition, were visually isolated and could exchange vocalizations in another condition, and were visually isolated and subsequently totally isolated in a third condition. We recorded 6,035 phees of 10 male,female marmoset pairs and conducted acoustic analysis. The marmosets frequently vocalized phees that were temporally elongated and louder during isolation, with varying time courses of these changes in acoustic parameters. The vocal rates and sound levels of the phees increased as soon as the marmosets saw their pair mates being taken away, and then gradually calmed down. The phee duration was longer in conditions during which there were no vocal responses from their pair mates. Louder vocalizations are conspicuous and seem to be effective for long-distance transmission, whereas shorter call duration during vocal exchanges might avoid possible vocal overlap between mates. Am. J. Primatol. 72:681,688, 2010. © 2010 Wiley-Liss, Inc. [source] The structure of vocalization of ewes and male lambs at pastureANIMAL SCIENCE JOURNAL, Issue 1 2009Hirofumi NAEKAWA ABSTRACT We performed an analysis of the vocalization of 161 ewes and 50 male lambs that were pastured day and night. The vocalization structures of the phonetic notations of the opened-mouth from closed mouth /,aee/ and /,naeee/ and closed-mouth /,,,,/ of ewes, and the opened-mouth from closed-mouth /,eee/ and /,neeee/ and closed-mouth /,,,,/ of male lambs were studied in terms of their audio characteristics. The items subject to analysis included duration of each vocalization, fundamental frequency, sound pressure and first formant (F1), second formant (F2), and third formant (F3). Among the male lambs, the duration of each call type showed significant differences depending on the behavior types or the target types, and the closed-mouth to open-mouth sounds, /,eee/ and /,neeee/ showed a tendency to be longer than the closed-mouth sound of /,,,,/. A significant correlation (r = 0.9, P < 0.05) was observed between the fundamental frequency and F1 with the /,eee/ type of call of the male lambs when the vocalization was targeted toward the stockperson. When the ewes' behavior pattern was grazing and moving and the calling target was an ewe, the sound pressure significantly differed between /,,,,/ and /,naeee/ (P < 0.05). From the analysis of the call durations, the fundamental frequencies, the sound pressures and formants, and the particular characteristics in sound structure were shown to vary according to the vocalization conditions and the situations, and where the animals were placed, even within the same call types. [source] | ||||||||||