ABSTRACT
Vertebrates communicate through a wide variety of sounds, but few mechanisms of sound production, besides vocalization, are well understood. During high-speed dives, male trainbearer hummingbirds (Lesbia spp.) produce a repeated series of loud snaps. Hypotheses for these peculiar sounds include the birds employing their elongated tails and/or striking their wings against each other. Each snap to human ears seems like a single acoustic event, but sound recordings revealed that each snap is actually a couplet of impulsive, atonal sounds produced â¼13â ms apart. Analysis of high-speed videos refutes these previous hypotheses, and furthermore suggests that this sonation is produced by a within-wing mechanism - each instance of a sound coincided with a distinctive pair of deep wingbeats (with greater stroke amplitude, measured for one display sequence). Across many displays, we found a tight alignment between a pair of stereotyped deep wingbeats (in contrast to shallower flaps across the rest of the dive) and patterns of snap production, evidencing a 1:1 match between these sonations and stereotyped kinematics. Other birds including owls and poorwills are reported to produce similar sounds, suggesting that this mechanism of sound production could be somewhat common within birds, yet its physical acoustics remain poorly understood.
Subject(s)
Passeriformes , Strigiformes , Animals , Feathers , Flight, Animal , Male , Sound , Wings, AnimalABSTRACT
El vireo verdeamarillo (Vireo flavoviridis) es una especie de ave migratoria que no cuenta con registros en literatura dentro del departamento de Cundinamarca. Adicionalmente, la distribución conocida de V. flavoridis en Colombia solo incluye localidades por debajo de 1500 msnm. Dos individuos de V. flavoviridis fueron vistos a 2600 msnm en el campus de Bogotá de la Universidad Nacional de Colombia, dentro de la Sabana de Bogotá del departamento de Cundinamarca en 2011. Posterior a consulta en colecciones y reportes de observadores de aves, encontramos 18 registros no publicados de la especie para el departamento de Cundinamarca por encima de 2500 msnm. Diez registros fueron a partir de colecciones científicas (Instituto de Ciencias Naturales de la Universidad Nacional de Colombia, Colección de Vertebrados (Ornitología) de la Universidad de los Andes y colección del Instituto de Investigación en Recursos Biológicos Alexander von Humboldt), y los otros ocho por reportes de observadores de aves. El primer registro fue en 1964, pero la mayoría de registros corresponden al período entre 2008 y 2013. Consideramos que V. flavoviridis ha pasado desapercibido en Cundinamarca por las similitudes morfológicas con el vireo ojirrojo (V. olivaceus). Además, la falta de revisión de colecciones científicas y un inconstante depósito de especímenes en ellas, genera un vacío de información sobre la distribución de la biodiversidad. Al parecer, V. flavoviridis puede ser más común de lo que se espera por encima de 1500 m durante migración, como ocurre para el departamento de Cundinamarca.
The Yellow-green Vireo (Vireo flavoviridis) is migrant bird specie, previously non reported to Cundinamarca Department. Distribution known in Colombia only includes localities below 1500 masl. Two individuals of the Yellow-green Vireo were observed at 2600 masl in the Universidad Nacional de Colombia Bogotá Campus, at the Sabana de Bogotá in Cundinamarca Department in 2011. In addition, we found 18 unpublished records for this species in the Cundinamarca Department above 2500 masl. Ten records were museum specimens (Instituto de Ciencias Naturales de la Universidad Nacional de Colombia, Vertebrate collection (Ornitology) Universidad de los Andes and Instituto de Investigación en Recursos Biológicos Alexander von Humboldt Museum), and the other eight were birdwatching records. The oldest record was in 1964, but the great majority of records were collected between 2008 and 2013. We consider that the Yellow-green Vireo has been unnoticed in the Cundinamarca Department because of its morphological similarities with the Red-eye Vireo (V. olivaceus). Furthermore, the lack of review of scientific collections, and the deposition of specimens discontinuous there, make gap information about biodiversity distribution. Apparently, Yellow-green Vireo could be more common than expected above 1500 m during its migration, such as it was observed in at Cundinamarca Department.
