Males of a suboscine bird (Ceratopipra mentalis) exhibit individual distinctiveness in their contact call

Abstract

The ability to discriminate among individual conspecifics may play a role in competition, mate selection, and other social interactions. Studies of individual distinctiveness in birds have traditionally focused on oscines, owing to the assumption that the less vocally complex suboscines would be incapable of producing individually distinct vocalizations. Nevertheless, while studies remain limited, a growing body of literature indicates that suboscines are capable of producing individually distinct vocalizations. Ceratopipra mentalis, the red-capped manakin, is a lekking suboscine and an important seed disperser. This study investigates whether individual distinctiveness in the whistle-peep vocalization, a contact call between males, of C. mentalis exists by recording males at multiple leks in Panama. Using flexible discriminant function analyses, we found individual distinctiveness in temporal and frequency traits of the whistle-peep call structure. We were able to classify individuals with 81.1% accuracy, comparable to other studies of suboscines. These results provide further evidence that the absence of song learning and less complex syrinxes in suboscines do not preclude individual distinctiveness in vocalizations. While studies focus on territorial species, here we found individual distinctiveness in a non-territorial lekking species. We argue for the need to examine the role of vocalizations in mate selection and male-male competition in these species with intense sexual selection. Lastly, our results suggest that acoustic monitoring may be a useful path forward to obtain a rapid assessment of male population abundance in C. mentalis and potentially other suboscine species, critical given predicted changes in species with climate change and other human-induced impacts.