Acoustic and Temporal Variation in Gelada (Theropithecus gelada) Loud Calls Advertise Male Quality
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Many animals rely on information from vocal signals to assess potential competitors and mates. For example, in primates, males use loud calls to assess rivals when the acoustic properties of the calls reliably indicate the condition or quality of the sender. Here, we investigate whether the loud calls of male geladas (Theropithecus gelada) function as a quality signal. Gelada males produce loud calls during ritualistic chases with rival males. Given the physically taxing nature of these displays, we hypothesize that variation in the acoustic properties of loud calls reliably signal male stamina or competitive ability. To test this hypothesis, we examined whether the acoustic properties of the gelada loud call varied in relation to individual, age, status, and exhaustion. Specifically, we examined 12 call parameters (e.g., fundamental frequency) and 3 bout parameters (e.g., number of calls per bout), that have been previously shown to vary across condition in male primates. We found that several acoustic features varied consistently across age and status such that males deemed higher quality in gelada society (e.g., high status) produced more calls per bout, produced calls that were lower in overall frequency measures, and exhibited a greater vocal range. In addition, we found that similar acoustic features varied with exhaustion; after a long chase event, males produced both fewer calls per bout and calls with higher spectral measures. Results from this study are consistent with the hypothesis that gelada loud calls are quality signals, contributing to the growing evidence that primates may use acoustic information to assess the quality of a rival or a potential mate.
KeywordsAcoustic analysis Mate choice Quality signal Rival assessment Sexual selection Theropithecus
- Bates, D., Maechler, M., Bolker, B., Walker, S., Christensen, R. H. B., et al. (2015). Package lme4. (http://lme4.r-forge.r-project.org/).
- Beehner, J. C., Gesquiere, L., Seyfarth, R. M., Cheney, D. L., Alberts, S. C., Altmann, J. (2015). Corrigendum to “Testosterone related to age and life-history stages in male baboons and geladas.” [Hormones and Behavior 56/4 (2009) 472–480]. Hormones and Behavior. Google Scholar
- Dunbar, R. I. M. (1984). Reproductive decisions: An economic analysis of gelada baboon social strategies. Princeton: Princeton University Press.Google Scholar
- Dunbar, R. I. M., & Dunbar, P. (1975). Social dynamics of gelada baboons. In H. Kuhn, W. P. Luckett, C. R. Noback, A. H. Schultz, D. Starck, & F. S. Szalay (Eds.), Contributions to primatology. Basel: S. Karger.Google Scholar
- Fischer, J., Kitchen, D. M., Seyfarth, R. M., Cheney, D. L. (2004). Baboon loud calls advertise male quality: Acoustic features and their relation to rank, age, and exhaustion. Behavioral Ecology and Sociobiology, 140–148.Google Scholar
- Hall, K. R. L., & DeVore, I. (1965). Baboon social behavior. In I. DeVore (Ed.), Primate behavior: Field studies of monkeys and apes (pp. 53–110). New York: Holt, Rinehart and Winston.Google Scholar
- Kitchen, D. M., Seyfarth, R. M., Fischer, J., & Cheney, D. L. (2003). Loud calls as indicators of dominance in male baboons (Papio cynocephalus ursinus). Behavioral Ecology and Sociobiology, 53, 374–384.Google Scholar
- Mori, U. (1979a). Social structure of gelada baboons. In M. Kawai (Ed.), Ecological and sociological studies of gelada baboons (Vol. 16, pp. 243–247). Basel: S. Karger.Google Scholar
- Mori, U. (1979b). Unit formation and the emergence of a new leader. In M. Kawai (Ed.), Ecological and sociological studies of gelada baboons (Vol. 16, pp. 155–181). Basel: S. Karger.Google Scholar
- Tomasello, M., & Call, J. (1997). Primate cognition. New York: Oxford University Press.Google Scholar
- Vehrencamp, S. (2000). Handicap, index, and conventional signal elements of bird song. In Y. Espmark, T. Amundsen, & G. Rosenqvist (Eds.), Animal signals: signalling and signal design in animal communication (pp. 227–300). Trondheim: Tapir Academic Press.Google Scholar