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Frey R.,Leibniz Institute for Zoo and Wildlife Research | Volodin I.,Moscow State University | Volodina E.,Moscow Zoo | Soldatova N.V.,Ecocenter Djeiran | Juldaschev E.T.,Ecocenter Djeiran
Journal of Anatomy | Year: 2011

Similar to male humans, Homo sapiens, the males of a few polygynous ruminants - red deer Cervus elaphus, fallow deer Dama dama and Mongolian gazelle Procapra gutturosa- have a more or less enlarged, low-resting larynx and are capable of additional dynamic vocal tract elongation by larynx retraction during their rutting calls. The vocal correlates of a large larynx and an elongated vocal tract, a low fundamental frequency and low vocal tract resonance frequencies, deter rival males and attract receptive females. The males of the polygynous goitred gazelle, Gazella subgutturosa, provide another, independently evolved, example of an enlarged and low-resting larynx of high mobility. Relevant aspects of the rutting behaviour of territorial wild male goitred gazelles are described. Video and audio recordings served to study the acoustic effects of the enlarged larynx and vocal tract elongation on male rutting calls. Three call types were discriminated: roars, growls and grunts. In addition, the adult male vocal anatomy during the emission of rutting calls is described and functionally discussed using a 2D-model of larynx retraction. The combined morphological, behavioural and acoustic data are discussed in relation to the hypothesis of sexual selection for male-specific deep voices, resulting in convergent features of vocal anatomy in a few polygynous ruminants and in human males. © 2011 The Authors. Journal of Anatomy © 2011 Anatomical Society of Great Britain and Ireland. Source

Volodin I.A.,Moscow State University | Lapshina E.N.,Moscow State University | Volodina E.V.,Moscow Zoo | Frey R.,Leibniz Institute for Zoo and Wildlife Research | Soldatova N.V.,Ecocenter Djeiran
Ethology | Year: 2011

Like many other gazelles, goitred gazelles (Gazella subgutturosa) are capable of calling either through the nose or through the open mouth. In particular, juvenile goitred gazelles provide a convenient model for contrasting acoustic characteristics of nasal and oral calls, and for estimating their communicative functions. In this study, acoustic variables (formants, fundamental frequency, duration and power quartiles) of 480 oral and 483 nasal calls, recorded from 20 (9 male, 11 female) individually identified captive juvenile goitred gazelles, were examined for their potential to encode sex and identity of the caller. Discriminant function analysis revealed an equally high potential of oral and nasal calls to encode sex, whereas encoding the individual identity was significantly more accurate for oral calls. Sex was encoded exclusively in formants, whilst individual identity was encoded in a combination of all investigated variables. No correlation was found between body mass and values of any acoustic variable. Analyses controlling for age and sex revealed higher average values for all investigated variables of oral calls compared to nasal calls. We discuss the results in relation to the source-filter theory, mother-offspring communication and production mechanisms of nasal and oral calls in mammals. © 2011 Blackwell Verlag GmbH. Source

Lapshina E.N.,Moscow State University | Volodin I.A.,Moscow State University | Volodina E.V.,Moscow Zoo | Frey R.,Leibniz Institute for Zoo and Wildlife Research | And 2 more authors.
Behavioural Processes | Year: 2012

Individualistic voices are important for establishing personalized relationships among individuals. In young animals, individual vocal identity is affected by permanent changes of the acoustics due to the growth of their vocal apparatus. Different acoustic variables change uncoordinatedly, so vocal individuality should be repeatedly upgraded along development. We compared classifying accuracy of individuals and sexes by nasal calls in fast-growing goitred gazelles Gazella subgutturosa at two ontogenetic stages, juvenile (3-6 weeks of age) and adolescent (23-26 weeks of age). Juvenile "spring" nasal calls and adolescent "fall" nasal calls were examined in the same 35 calves (18 males, 17 females), wild-born in May and then hand-raised. Discriminate function analysis based on four formants, fundamental frequency, duration and three power quartiles, revealed an equally high potential of spring and fall calls to encode sex. The individuality was very high in both ages but significantly higher in fall calls. Classifying calls to individuals was based on the same three acoustic variables (fundamental frequency and third and fourth formants) in both ages, although their actual values changed uncoordinatedly from spring to fall in most subjects. Our results suggest updating acoustic individuality in nasal calls of adolescent goitred gazelles accordingly to the newly emerged acoustic variation. © 2012 Elsevier B.V. Source

Efremova K.O.,Moscow State University | Volodin I.A.,Moscow State University | Volodina E.V.,Moscow Zoo | Frey R.,Leibniz Institute for Zoo and Wildlife Research | And 2 more authors.
Naturwissenschaften | Year: 2011

In goitred gazelles (Gazella subgutturosa), sexual dimorphism of larynx size and position is reminiscent of the case in humans, suggesting shared features of vocal ontogenesis in both species. This study investigates the ontogeny of nasal and oral calls in 23 (10 male and 13 female) individually identified goitred gazelles from shortly after birth up to adolescence. The fundamental frequency (f0) and formants were measured as the acoustic correlates of the developing sexual dimorphism. Settings for LPC analysis of formants were based on anatomical dissections of 5 specimens. Along ontogenesis, compared to females, male f0 was consistently lower both in oral and nasal calls and male formants were lower in oral calls, whereas the first two formants of nasal calls did not differ between sexes. In goitred gazelles, significant sex differences in f0 and formants appeared as early as the second week of life, while in humans they emerge only before puberty. This result suggests different pathways of vocal ontogenesis in the goitred gazelles and in humans. © 2011 Springer-Verlag. Source

Efremova I A Volodin K.O.,Moscow State University | Volodina E.V.,Moscow Zoo | Frey R.,Leibniz Institute for Zoo and Wildlife Research | Soldatova N.V.,Ecocenter Djeiran | And 3 more authors.
Zoologicheskii Zhurnal | Year: 2011

Goitred gazelle males as compared to conspecific females have a highly prominent larynx. However, the development of sex dimorphism in vocal apparatus and call traits has not yet been studied for this species. Structural shifts in the acoustic characteristics of nasal calls and in the body size of the goitred gazelle calves in the course of ontogenesis from birth to six month of age are described. The body mass and neck girths showed the linear increase with age. Consistently, the fundamental frequency of nasal calls decreased progressively with the body growth and body mass gain. At the same time, the duration and power parameters of nasal calls varied nonlinearly with age. Nasal calls of goitred gazelle's calves were much lower in the fundamental frequency (94 Hz in males and 118 Hz in females at the age of 2 weeks) than in juveniles of any other ungulate species of comparable size. In the goitred gazelle calves, the coefficients of sex differences in the fundamental frequency of nasal calls in the animals of each age exceeded as minimum twice the corresponding coefficients in body mass and neck girths. This fact suggests that the laryngeal hypertrophy in males develops already at their birth. The degree of sex differences in the nasal call fundamental frequency did not increase in the animals up to their 6-month age. The accelerated growth of male larynx as compared to those in females appears to start later, at the puberty stage, under the action of sex hormones. Source

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