Functional morphology of the avian syrinx: A comparative histological analysis of the syrinx in select passerines

FUXJAGER, MATTHEW; KOPUCHIAN, CECILIA; GOLLER, FRANZ; GARCIA, SARAH; RIEDE, TOBIAS

washington dc

Congreso; VI North American Ornithological Congress; 2016

Vocal behavior of birds is highly diverse and encompasses a broad range of acoustic features. Despite centuries of study of the morphology of the avian vocal organ, the syrinx, relatively little is known on how morphology relates to function. Histological features of the syrinx, particularly those of the labia as sound producing structures, play an integral role in phonation. The elasticproperties, size, orientation, and muscular control of the labia significantly impact phonation. Here, we present data on the diversity of syringeal histological composition in the context of comparing suboscines to oscines. The current histological data describing oscine syringes indicate a positive and nonlinear correlation between vocal and histological complexity of labia. We test the hypothesis that vocal learning and vocal motor control is associated with morphological complexity. We compare histological composition across 7 oscine species and 7 suboscine species, and relate this to key acoustic variables determined by syringeal design and motor control. Various specializations characterize the syrinx of different species, suggesting a morphological basis for specific acoustic features of the respective vocal repertoires.