title: Difference between the vocalizations of two sister species of pigeons explained in dynamical terms.
abstract: Vocal communication is an unique example, where the nonlinear nature of the periphery can give rise to complex sounds even when driven by simple neural instructions. In this work we studied the case of two close-related bird species, Patagioenas maculosa and Patagioenas picazuro, whose vocalizations differ only in the timbre. The temporal modulation of the fundamental frequency is similar in both cases, differing only in the existence of sidebands around the fundamental frequency in the P. maculosa. We tested the hypothesis that the qualitative difference between these vocalizations lies in the nonlinear nature of the syrinx. In particular, we propose that the roughness of maculosa's vocalizations is due to an asymmetry between the right and left vibratory membranes, whose nonlinear dynamics generate the sound. To test the hypothesis, we generated a biomechanical model for vocal production with an asymmetric parameter Q with which we can control the level of asymmetry between these membranes. Using this model we generated synthetic vocalizations with the principal acoustic features of both species. In addition, we confirmed the anatomical predictions by making post mortem inspection of the syrinxes, showing that the species with tonal song (picazuro) has a more symmetrical pair of membranes compared to maculosa.
authors.affiliation: Department of Physics, FCEN, University of Buenos Aires and IFIBA, CONICET, Buenos Aires, Argentina. ralonso@df.uba.ar.
authors.forename: R Gogui
authors.initials: RG
authors.lastname: Alonso
authors.affiliation: División Ornitología, Museo Argentino de Ciencias Naturales "Bernardino Rivadavia" (MACN - CONICET), Avenida Ángel Gallardo 470, C1405DJR, Buenos Aires, Argentina.|Laboratorio de Biología de la Conservación, Centro de Ecología Aplicada del Litoral (CECOAL - CONICET), Ruta Provincial 5, Km 2.5, CEP 3400, Corrientes, Argentina.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Kopuchian
authors.affiliation: Department of Physics, FCEN, University of Buenos Aires and IFIBA, CONICET, Buenos Aires, Argentina.
authors.forename: Ana
authors.initials: A
authors.lastname: Amador
authors.affiliation: Department of Physics, FCEN, University of Buenos Aires and IFIBA, CONICET, Buenos Aires, Argentina.
authors.forename: Maria de Los Angeles
authors.initials: Mde L
authors.lastname: Suarez
authors.affiliation: División Ornitología, Museo Argentino de Ciencias Naturales "Bernardino Rivadavia" (MACN - CONICET), Avenida Ángel Gallardo 470, C1405DJR, Buenos Aires, Argentina.
authors.forename: Pablo L
authors.initials: PL
authors.lastname: Tubaro
authors.affiliation: Department of Physics, FCEN, University of Buenos Aires and IFIBA, CONICET, Buenos Aires, Argentina.
authors.forename: Gabriel B
authors.initials: GB
authors.lastname: Mindlin
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D010856:Columbidae / Q000033:anatomy & histology / Q000502:physiology; D003198:Computer Simulation; D008297:Male; D008962:Models, Theoretical; D017711:Nonlinear Dynamics; D013018:Sound Spectrography; D013045:Species Specificity; D014732:Vibration; D014828:Vocalization, Animal
keywords: Asymmetry; Biomechanics; Birdsong; Nonlinear dynamics; Vocal control