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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.

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., (Copyright © 2012 Elsevier B.V. All rights reserved.)