Vocal correlates of mate quality and proceptivity in the vocalizations of white rhinoceros

• Applicant: Dr. Marina Scheumann
• Subject Area: Sensory and Behavioural Biology
• Term: from 2017 to 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 376018728

Non-verbal acoustic cues of the human voice are suggested to be an ornament signaling mate quality and therefore have an important impact on sexual behavior and mate choice. Thus, acoustic cues contain information about the physical characteristic, the motivational state and the level of sex hormones of the sender. Studies in nonhuman mammals revealed similar vocal correlates suggesting that vocal correlates in nonhuman mammals reflect also important proximate mechanisms for sexual behavior and mate choice. Such vocal correlates should play an important role in non-seasonally breeding large-bodied species. Because males and females often live separated from each other and females have a low reproductive output, it is important to find a high-quality mating partner at the right time. However, data on vocal correlates on such species are limited, therefore this project will investigate, as a first essential step, whether vocal correlates as proximate mechanisms for sexual behavior and mate choice, in the Southern white rhinoceros. To date, data on vocal correlates related to the motivational state and the hormonal level of the sender are lacking in rhinoceros and data on physical characteristics are limited to only one call type. Thus, the whole project will consist of four studies. These studies will investigate whether in white rhinoceros vocal correlates related to (1) the physical characteristics of the sender, (2) the motivational state of the sender, (3) the level of sex hormones in the sender exists and whether (4) conspecifics can recognize the fertility of females or male quality based on their voices. Thereby, these vocal correlates might encode mate quality, the willingness to mate as well as the reproductive status of the sender and will play an important role in sexual behavior. Combining the results of the Southern white rhinoceros with findings in group living mammals or/and seasonal breeders will allow a deeper understanding how vocal mating behavior is shaped by social structure of and/or mating strategy. Thus, the project will help to clarify the biological function and principles of vocal correlates on sexual interactions and mating behavior in mammals.

• DFG Programme: Research Grants