Vocal variation among and within four genomically similar, highly sympatric southern capuchinos (genus Sporophila)

ESTALLES, CECILIA; ODOM, KARAN J; CAMPAGNA, LEONARDO; ARAYA-SALAS, MARCELO; BARONE, M. LAURA; RODRIGUEZ-CAJARVILLE, MARÍA JOSÉ; LUCERO, SERGIO; TUBARO, PABLO L.; LIJTMAER, DARÍO A.

London

Congreso; AOS & SCO?SOC 2023; 2023

American Ornithological Society (EEUU) y Society of Canadian Ornithologists

For many songbirds, acoustic signals constitute prezygotic reproductive barriers that are key for the co-existence of closely related species in sympatry and are thus the target of natural and sexual selection. This is the case in the southern capuchinos, a recent radiation in the genus Sporophila comprised of ten geographically overlapping species that have remarkably low genomic divergence but for which their notorious differences in coloration and vocalizations have been shown to be critical for species recognition. In this context, we studied the acoustic signals of four species of this group and recorded their songs at five localities where they breed in different degrees of sympatry. We measured acoustic variables per note and per song, and studied inter- and intra-specific patterns of variation, with focus on the effect of sympatry with other capuchinos and geographic distance among individuals. Overall, these capuchinos are very similar acoustically but differ in particular combinations of acoustic variables that characterized each species individually. The genomically more differentiated species (S. iberaensis) is also the most acoustically differentiated. At the population level, song characteristics can be affected by the presence or absence of other capuchinos in the area and intraspecific variation is associated with geographic distance among individuals. Our analysis found acoustic differences among these four genomically similar, highly overlapping members of the capuchino radiation that could be responsible for species recognition and also sets the ground for future research about the role of selective and neutral processes in shaping intraspecific variation in the acoustic signals of the group.