Bird tolerance to humans in open tropical ecosystems

AbstractAnimal tolerance towards humans can be a key factor facilitating wildlife–human coexistence, yet traits predicting its direction and magnitude across tropical animals are poorly known. Using 10,249 observations for 842 bird species inhabiting open tropical ecosystems in Africa, South America, and Australia, we find that avian tolerance towards humans was lower (i.e., escape distance was longer) in rural rather than urban populations and in populations exposed to lower human disturbance (measured as human footprint index). In addition, larger species and species with larger clutches and enhanced flight ability are less tolerant to human approaches and escape distances increase when birds were approached during the wet season compared to the dry season and from longer starting distances. Identification of key factors affecting animal tolerance towards humans across large spatial and taxonomic scales may help us to better understand and predict the patterns of species distributions in the Anthropocene.</jats:p

Evaluación preliminar de la estructura filogeográfica de la Tángara Triguera (Tangara cayana, Aves: Thraupidae) en la Orinoquía colombiana

Incluye tablas, figuras y símbolos.Los estudios sobre filogeografía de aves Neotropicales se han centrado en gran medida en taxones de bosques húmedos de tierras bajas. En contraste, poca atención ha sido dedicada al estudio de especies con ecologías propicias para la dispersión, tales como los asociados a ecosistemas no boscosos y acuáticos. A pesar de un incremento reciente en estudios filogeográficos de aves de ecosistemas no boscosos aún existe un vacío de conocimiento en ecosistemas de sabana al norte del río Amazonas. En este trabajo se evaluó la estructura filogeográfica de Tangara cayana con énfasis en la Orinoquia colombiana a partir de secuencias del gen mitocondrial ND2. A nivel de especie, las poblaciones mostraron baja estructura genética; sin embargo, se presentan tres haplogrupos correspondientes a poblaciones de Bolivia, Brasil y noreste de la Orinoquia colombiana, el sur de la Orinoquia colombiana y Amazonas. La baja estructura genética encontrada no concuerda con la delimitación tradicional de distritos biogeográficos para la Orinoquia. Las poblaciones de la Orinoquia colombiana probablemente derivaron de poblaciones de Brasil más que de Bolivia, lo cual posiblemente pudo ser promovido por la expansión de las sabanas durante las oscilaciones climáticas del Pleistoceno. Es de precisar que los resultados encontrados en este estudio deben ser complementados con un mayor número de muestras y poblaciones de T. cayana en la Orinoquia colombiana y venezolana, con la finalidad de obtener un escenario filogeográfico más completo de la especie.Phylogeographic studies of Neotropical birds have mostly on taxa from the lowland humid forests. In contrast, little attention has been devoted to the study of species with ecologies with higher propensity for dispersal, such as those associated with non-forest and aquatic ecosystems. In this paper the phylogeographic structure in the Colombian Orinoquia of Tangara cayana was evaluated using sequenced data of mitochondrial ND2 gene. At the species level, populations exhibited shallow genetic structure; however, three haplogroups were represented in the Colombian Orinoquian savannahs, which have affinities with populations of Bolivia, Brazil and northeastern Colombia, and southern Colombia. The low genetic structure found does not match the traditional definition of biogeographic districts for Orinoquia. The populations of the Colombian Orinoco basin probably derived from Brazil, which possibly could be promoted by the expansion of savannahs during the Pleistocene climatic oscillations. Results from this study may be supplemented with samples from the Colombian and Venezuelan Orinoquian, in order to obtain a more complete phylogeographic scenario of the species.Lista de figuras. -- Lista de tablas. -- Lista de símbolos y abreviaturas. -- Planteamiento del problema. -- Hipótesis. -- Objetivos. -- Objetivo general. -- Objetivos específicos. – Justificación. -- Marco teórico. -- Metodología. -- Muestreo taxonómico y geográfico. -- Extracción de ADN, PCR y secuenciación. -- Análisis filogeográficos. – Resultados. -- Análisis filogenéticos. -- Estructura geográfica y diversidad genética. -- Historia demográfica y tiempos de divergencia. -- Discusión. -- Origen y diversificación de T. cayana. -- Estructura Genética Poblacional en la Orinoquia Colombiana. -- Conclusiones. -- Bibliografía.PregradoBiólogoBiologí

Bird tolerance to humans in open tropical ecosystems

Animal tolerance towards humans can be a key factor facilitating wildlife-human coexistence, yet traits predicting its direction and magnitude across tropical animals are poorly known. Using 10,249 observations for 842 bird species inhabiting open tropical ecosystems in Africa, South America, and Australia, we find that avian tolerance towards humans was lower (i.e., escape distance was longer) in rural rather than urban populations and in populations exposed to lower human disturbance (measured as human footprint index). In addition, larger species and species with larger clutches and enhanced flight ability are less tolerant to human approaches and escape distances increase when birds were approached during the wet season compared to the dry season and from longer starting distances. Identification of key factors affecting animal tolerance towards humans across large spatial and taxonomic scales may help us to better understand and predict the patterns of species distributions in the Anthropocene