Ecocenter Djeiran

Bukhara, Uzbekistan

Ecocenter Djeiran

Bukhara, Uzbekistan
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Volodin I.A.,Moscow State University | Sibiryakova O.V.,Moscow State University | Frey R.,Leibniz Institute for Zoo and Wildlife Research | Efremova K.O.,Russian National Research Medical University | And 5 more authors.
Ethology | Year: 2017

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. © 2017 Blackwell Verlag GmbH

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.

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.

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.

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.

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.

Volodin I.A.,Moscow State University | Volodina E.V.,Moscow Zoo | Lapshina E.N.,Moscow State University | Efremova K.O.,Moscow State University | Soldatova N.V.,Ecocenter Djeiran
Animal Cognition | Year: 2014

The potential for vocal modification in mammals has recently been of great interest. This study focuses on the potential for vocal matching in juvenile and adolescent goitred gazelles Gazella subgutturosa that were group housed as part of an animal management programme. Two groups of animals (16 and 19 unrelated individuals, respectively) were recorded at two different ages, juvenile and adolescent, regarding 20-25 calls per individual per age; each group was evaluated in a separate year. Vocal similarity of group members compared to non-members was prominent in both ages, but higher in juveniles. Individual identity was prominent in both ages and higher in adolescents. The more prominent vocal indicators of group membership in juveniles could be related to their higher social dependence compared to adolescents. The more individualized calls of adolescents could be a mechanistic consequence of more stable growth at older age. Our results suggest vocal plasticity of goitred gazelles under social influences. These data add to recent evidence about domestic goat kids Capra hircus, suggesting that vocalizations of species that are not capable of imitation are more flexible than previously thought. © 2013 Springer-Verlag Berlin Heidelberg.

PubMed | Russian National Research Medical University, Moscow State University, Moscow Zoo, Ecocenter Djeiran and Leibniz Institute for Zoo and Wildlife Research
Type: Journal Article | Journal: Journal of morphology | Year: 2016

This study quantitatively documents the progressive development of sexual dimorphism of the vocal organs along the ontogeny of the goitred gazelle (Gazella subgutturosa). The major, male-specific secondary sexual features, of vocal anatomy in goitred gazelle are an enlarged larynx and a marked laryngeal descent. These features appear to have evolved by sexual selection and may serve as a model for similar events in male humans. Sexual dimorphism of larynx size and larynx position in adult goitred gazelles is more pronounced than in humans, whereas the vocal anatomy of neonate goitred gazelles does not differ between sexes. This study examines the vocal anatomy of 19 (11 male, 8 female) goitred gazelle specimens across three age-classes, that is, neonates, subadults and mature adults. The postnatal ontogenetic development of the vocal organs up to their respective end states takes considerably longer in males than in females. Both sexes share the same features of vocal morphology but differences emerge in the course of ontogeny, ultimately resulting in the pronounced sexual dimorphism of the vocal apparatus in adults. The main differences comprise larynx size, vocal fold length, vocal tract length, and mobility of the larynx. The resilience of the thyrohyoid ligament and the pharynx, including the soft palate, and the length changes during contraction and relaxation of the extrinsic laryngeal muscles play a decisive role in the mobility of the larynx in both sexes but to substantially different degrees in adult females and males. Goitred gazelles are born with an undescended larynx and, therefore, larynx descent has to develop in the course of ontogeny. This might result from a trade-off between natural selection and sexual selection requiring a temporal separation of different laryngeal functions at birth and shortly after from those later in life. J. Morphol. 277:826-844, 2016. 2016 Wiley Periodicals, Inc.

PubMed | Russian National Research Medical University, Moscow State University, Moscow Zoo, Ecocenter Djeiran and Leibniz Institute for Zoo and Wildlife Research
Type: | Journal: Zoology (Jena, Germany) | Year: 2016

The pronouncedly enlarged and descended larynx in male goitred gazelles (Gazella subgutturosa), Mongolian gazelles (Procapra gutturosa) and fallow deer (Dama dama) represents an interesting parallel to the Adams apple of human males. Goitred gazelles, as humans, are not born with a descended larynx. Therefore the sexual dimorphism of larynx size and position develops during ontogeny. In this study, the vocal ontogeny of male and female goitred gazelles was investigated across five age classes from neonates to adults. The acoustic variables of nasal contact calls were measured in 53 (24 male, 29 female) individuals, body mass and neck dimensions in 63 (31 male, 32 female) live individuals and nasal vocal tract and vocal fold lengths in 26 (16 male, 10 female) anatomical specimens. Call fundamental frequency (f0), the acoustic correlate of the ontogenetically enlarging larynx, decreased significantly in either sex. Call formants (second, third and forth), the acoustic correlates of the ontogenetically elongating vocal tract, did not differ significantly between sexes up to early adulthood, but clearly diverged in adults. Significant differences between sexes in neck circumference at the level of the larynx emerged already at 2-3 months of age, whereas body mass, neck circumference at the neck-body transition and the degree of larynx descent significantly differed in adults only. We discuss that, in contrast to humans, the accelerated enlargement of the larynx in male goitred gazelles starts early in ontogeny. A moderate descent of the larynx develops equally in both sexes before early adulthood, whereas the additional prominent descent of the larynx in males is shifted to late ontogeny. This might avoid selective disadvantages of this sexually dimorphic trait on males during their period of growth. As has been previously proved for humans, the emergence of the strong male-specific descent of the larynx in goitred gazelles may go along with the increasing social status and the males increasing chances of siring offspring. Similar to the Adams apple of human males, this may indicate the important role of the enlarged and descended larynx for signaling male status via masculine voice.

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