Responses of a pair-living, sexually monogamous primate to the simulated presence of solitary individuals: A field playback experiment

GARCIA DE LA CHICA, ALBA; WOOD, DAVID BECHTEL; ROTUNDO, MARCELO; FERNANDEZ-DUQUE, EDUARDO

ETHOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Año: 2021 vol. 127 p. 1002 - 1018

0179-1613

Loud calls play an important function in regulating the use of space and structuring social groups and mating systems in a wide range of taxa. In pair-living territorial animals, where encounters with neighbors and solitary conspecifics are common, these calls are mainly associated with resource defense or mate guarding behaviors. Owl monkeys (Aotus azarae) live in groups of one pair of reproducing adults and 1?4 younger, non-reproducing individuals. Both sexes disperse when they are around 3 years of age; they become solitary floaters who compete to replace same-sex adults from other groups. Here, we examined the behavioral responses of Azara´s owl monkey pairs toward calls of unpaired and unfamiliar males and females to better understand if the competition between floaters and groups is in relationship to the defense of their territory, their mates, or both. We collected behavioral data from six groups, before, during, and after the playing back of unfamiliar male and female loud calls and of a control stimulus at the center and border of their home ranges. Overall, our results showed that the playback location did not elicit differential responses in the monkeys and that both sexes were more reactive to male than female unfamiliar calls, as evidenced by higher rates of sociosexual and vocal responses, movement toward the playback, and intergroup encounters during and after the experiments. Our study indicates that paired male and female owl monkeys mainly defend their partners toward intruders and emphasizes the need of including the role of sexual competition on both sexes in models about the evolution of pair-living social organizations and sexual monogamy mating systems.