Ornitología Neotropical (E-Journal)
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THE STUDY OF BIRD VOCALIZATIONS IN NEOTROPICAL HABITATS: CURRENT KNOWLEDGE AND FUTURE STEPS
Get PDFResearch on avian bioacoustics in the Neotropics has surged over the last several decades due to increased interest in the large diversity of vocal behaviors and vocalization and the broader accessibility of recording equipment and software. Here, we present a synthesis of the current and past knowledge of Neotropical bird bioacoustics. This synthesis is the result of the symposium "Bioacoustics in the Neotropics", organized for the XI Neotropical Ornithological Congress in San Jose, Costa Rica, in July 2019. We covered what we consider the main topics in avian bioacoustics that have been studied in this region over the last 30 years. Our review includes repertoire descriptions, geographic variation, diversity in vocal behaviors, seasonality, duetting, genetic association, and playback experiments. Additionally, we present information for what we believe may be the main veins of investigation for the coming future in the Neotropics, considering the large diversity of species that are found in the region and the new investigations developed in other geographic areas. We expect this review to work as a summary of the current literature and a guide to stimulate future research in important areas within the field of avian bioacoustics in the Neotropics
DIETA Y GASTROLITOS EN ATAJACAMINOS Y AÑAPEROS (CAPRIMULGIDAE) DEL NORDESTE ARGENTINO
Get PDFPara identificar recursos usados por los atajacaminos y añaperos (Caprimulgidae) es importante entender su dieta, que es poco conocida para especies del Neotrópico. En base a contenido estomacal de 19 individuos atropellados y fotografías de insectos hallados oportunistamente en las bocas de 13 individuos capturados, aportamos información sobre la dieta de 6 especies de Caprimulgidae en la Reserva Natural Rincón de Santa María, Corrientes, Argentina. Identificamos 424 insectos, incluyendo 7 órdenes, al menos 23 familias y 34 géneros en muestras de estómagos y bocas. Los órdenes más representados fueron Coleoptera (presas en estómagos: 88%; presas en bocas: 30%) y Lepidoptera (estómagos: 8%, bocas: 67%). El 85% de los coleópteros fueron de la familia Scarabaeidae (presentes en las seis especies de caprimúlgidos estudiados) y el 89% de los lepidópteros fueron de la familia Noctuidae (presentes en cinco de las especies de caprimúlgidos). Encontramos evidencia de ingesta de piedritas (gastrolitos) en 16% de los estómagos y en tres especies. Nuestros resultados resaltan la importancia de Scarabaeidae y Noctuidae en la dieta de atajacaminos en un sitio subtropical de alta diversidad de atajacaminos e insectos. Las diferencias que observamos entre estómagos y bocas refuerzan que los contenidos estomacales submuestrean presas blandas como lepidópteros, pero son útiles para determinar familias y géneros de coleópteros y fundamentales para detectar gastrolitos
FUNCTIONAL DIVERSITY OF AVIAN MIXED-SPECIES FORAGING FLOCKS ON THE TILARÁN CORDILLERA, COSTA RICA
Get PDFAvian mixed-species foraging flocks are a common phenomenon in neotropical forests. In order to characterize the variation in such flocks at different elevations, we studied the species composition of avian flocks over a 624 meter elevational gradient on both sides of the continental divide that crosses the Tilarán Cordillera in northwest Costa Rica. We characterized the change in diversity of these flocks across the elevational gradient using several diversity metrics: species richness, functional richness, functional evenness and functional divergence. While the lower elevations of the Atlantic side featured higher species richness, the lower elevations of the Pacific side featured the greatest functional richness and greatest functional divergence. Upper Elevations showed the lowest species richness and lowest functional evenness. A strong understanding of how functional diversity changes with elevation is important in the context of anticipated species altitudinal range shifts with climate change. 
EFECTO DE LA CARGA GANADERA DE CAMÉLIDOS DOMÉSTICOS SOBRE EL RIESGO DE PISOTEO DE NIDOS ARTIFICIALES EN HUMEDALES ALTOANDINOS DE AREQUIPA, PERÚ
Get PDFEl pastoreo por ganado puede tener efectos negativos sobre la biodiversidad de aves al reducir la calidad del hábitat, pisoteando nidos y facilitando la presencia de depredadores domésticos. Para los humedales altoandinos del Arequipa se ha considerado una carga óptima de 1,35 alpacas/ha y 0,9 llamas/ha, desconociéndose el efecto que dicha carga pudiese tener sobre la avifauna que anida en los humedales. En este estudio evaluamos el efecto de la carga ganadera de llamas y alpacas (pastoreo complementario) sobre la nidificación de aves en nueve humedales altoandinos de Arequipa, Perú. En diciembre 2021, implementamos un experimento con 900 nidos artificiales (100 nidos por sitio), expuestos durante 14 días en los humedales con distintas cargas ganaderas de llamas y alpacas. Determinamos que la carga ganadera tuvo un efecto significativo sobre los nidos artificiales, incrementando el pisoteo de los nidos. Además, 32,8% de los nidos fueron removidos por actividad humana. En vista de que las cargas de ganado constituyen una amenaza hacia las aves que anidan en humedales, recomendamos regular la carga ganadera, así como emplear sistemas de pastoreo rotativo y excluir el ganado en las épocas reproductivas de aves
PREVALENCE OF WHITE SPOTTING IN THE PLUMAGE OF THE FULVOUS WREN CINNYCERTHIA FULVA IN THE BOLIVIAN ANDES
Get PDFWe assessed the prevalence of white-spotting in the plumage of a Fulvous Wren Cinnycerthia fulva population and present evidence that this phenomenon occurs in other species populations. We captured and observed individuals with varying white facial patches in Cotapata National Park (La Paz, Bolivia). Fifty-two percent of the captured individuals (N=17) showed some degree of white feathering; in all cases, white patches occurred only on the head and fitted the description of ‘white-spotting’, a pattern likely associated with age, physical fitness and status. In avian community surveys, we often observed Fulvous Wrens attending mixed-species flocks, and 36% of all the flocks had at least one individual with facial white-spotting. An examination of photographic records of the species showed that spotting occurs in other populations, with most records from Bolivia showing some degree of facial white-spotting. Our study exemplifies the utility of citizen-science platforms for documenting atypical plumage in wild bird populations
OFFSPRING SEX RATIO IS RELATED WITH LAYING DATE AND HATCHING SEQUENCE IN THE MAGELLANIC PENGUIN SPHENISCUS MAGELLANICUS
Get PDFWe analyzed the variation in the secondary sex ratio of Magellanic Penguin Spheniscus magellanicus breeding in six colonies on the Patagonian coast of Argentina. We tested the effects of laying date and hatching sequence on the probability of producing sons and daughters. The global secondary sex ratio did not differ from equality, and there were no differences among the colonies. However, regardless of the colony, laying date, and hatching sequence, there was a significant effect on the proportion of males and females reared. Pairs that were laid early in the breeding season were more likely to raise a male. In addition, offspring that hatched first were more likely to be male than those that hatched second. Our results are consistent with the adaptive importance of producing males, likely the costliest sex, early in the breeding season or early in the brood when food resources are still abundant
EL ESTUDIO DE LAS AVES NEOTROPICALES DEBERÍA ABARCAR A LAS CIENCIAS SOCIALES
Get PDFLas poblaciones de aves en el continente Americano y la región Caribe están en declive. Revertir esta tendencia y conservar a las aves de una manera efectiva es una responsabilidad que debe compartirse entre todas las naciones de la región. El apoyo a los esfuerzos de conservación a menudo depende de una variedad de factores, muchos de los cuales tienen más que ver con las personas que con las aves. Por ejemplo, tener aprobración del sector político, administrativo y de las comunidades locales, es en general una estrategia necesaria para implementar políticas públicas relacionadas con la conservación. En los últimos años, ha surgido un campo académico en la intersección de la conservación de las aves y de las ciencias sociales. En este artículo, exploramos algunas de las raíces de dicho campo, e identificamos mecanismos para que la comunidad científica y los profesionales de la conservación puedan incorporar las ciencias sociales de la conservación en su trabajo y obtengan resultados más efectivos
SONG FREQUENCY SHIFTS IN AN URBAN BIRD SPECIES OPTIMIZE ACOUSTIC TRANSMISSION INSIDE NOISY URBAN AREAS
Get PDFIn animal acoustic communication is necessary that signals arrive to the receiver with reduced degradation and attenuation for a better transmission of the message. The noise pollution resulting from anthropogenic activities in cities reduces efficiency and efficacy of acoustic communication. Some species respond to high levels of noise increasing the minimum frequency of their vocalizations to avoid noise masking, but this may affect how sounds transmit in the environment because sounds with higher frequencies experience greater levels of attenuation and degradation. Using a transmission experiment, we analyzed how minimum frequency shifts, affect the sound transmission properties of the song of the House Wren (Troglodytes aedon) in urban areas that differ in the level of anthropogenic noise. We broadcasted songs with minimum frequencies between 1.2-1.8 kHz and the same songs with a minimum frequencies increment artificially of one semitone, increasing minimum frequencies to 2.1-2.6 kHz, in high and low noise level territories at four distances. We quantified signal-to-noise ratio, tail-to-signal ratio, blur ratio, and excess attenuation. Our results showed that songs with frequencies low minimum frequencies in low noise territories transmit with higher signal-to-noise ratio, and lower blur ratio and excess attenuation at longer distances. Songs with increased minimum frequencies only showed higher signal-to-noise ratio in noisier territories at longer distances. These results support the hypothesis of producing frequency shift to increase the communication distance in noisier environments. This is the first experimental study that tests the effect of shifting frequency on acoustic communication transmission on bird territories with different noise levels
EXTENSIÓN AUSTRAL DE LA DISTRIBUCIÓN DEL TECOLOTE TAMAULIPECO GLAUCIDIUM SANCHEZI, ESPECIE ENDÉMICA DE MÉXICO
Get PDFThe Tamaulipas Pygmy-Owl Glaucidium sanchezi is a Mexican endemic species that is currently classified as endangered. Its distribution is restricted to the forests of the Sierra Madre Oriental from the southern state of Tamaulipas to northern Hidalgo. This note updates the distribution of Tamaulipas Pygmy-Owl with the first record of the species in the state of Puebla, supported by photographic and auditory evidence. This record extends the species distribution by approximately 130 km to the south. Further studies of the species throughout its distribution are required, as much of its biology, ecology, and current population status remain unknown. In conclusion, the populations of Tamaulipas Pygmy-Owl located in the southern part of its range should receive greater attention because of their potential isolation and vulnerability to various threats, in order to prevent their disappearance