La descripción de patrones y mecánica de muda de las aves ha permitido esclarecer la dinámica en ciclos de vida de especies de zonas templadas. Pocos estudios evalúan estos aspectos en aves neotropicales, dificultando su discusión funcional y evolutiva. Acá comparamos la duración de muda de primarias e intensidad de muda de vuelo en dos especies de paseriformes neotropicales, V. jacarina y S. intermedia. Desarrollamos el estudio al norte del departamento de Tolima (Colombia); capturamos las aves en un matorral y las marcamos con anillos de colores. Utilizamos los métodos de Pimm, y Rohwer y Wang para estimar la duración, y calculamos la intensidad de muda según Rohwer. La duración de muda de V. jacarina fue de 59 días (IC 95 % = 48–74) y 80 días (IC 95 % = 64–96), mientras que para S. intermedia fue de 80 (IC 95 % = 66–105) y 100 días (IC 95 % = 75–124). Estos resultados fueron consistentes con la duración de muda de paseriformes con masas similares, aunque mayores que en especies de latitudes altas, apoyando la hipótesis del bajo ritmo de vida en evaluar la duración en especies con baja captura, con muda suspendida, o baja asincronía entre individuos. La intensidad de muda fue mayor en S. intermedia (13 plumas) que en V. jacarina (9,3 plumas), resultados mayores que otros paseriformes neotropicales, que pueden representar una respuesta adaptativa a presiones ecológicas específicas.

A significant gap in understanding the response of biodiversity to urban areas is the lack of long-term studies. Most of the information on urban birds comes from studies carried out in the northern hemisphere, and they include data that don't exceed three years. Although short-term studies contribute to knowledge about bird community diversity and their spatial distribution in urban areas, they could be biased towards more conspicuous and abundant species. One of the few multi-temporal datasets available for birds in urban areas is the Christmas Bird Count (CBC). Using annual CBC data available between 2001 and 2018 from 21 urban and peri-urban sample sites assessed from the main cities of Colombia, we identified and analyzed long-term trends on the cumulative diversity of bird communities as well as on their spatial distribution. We estimated comparative trends in richness, abundance, similarity, and complementarity of avifauna for each city and sample site based on their responses to urbanization and dietary guilds. We identified almost a quarter of the species registered in Colombia (464 of 1954). The representativeness of the community obtained during 18 years exceeds 84%, showing richness that ranges between 214 and 278 species in the three cities. Bird species and individuals registered showed wide variation of the sample sites. We found more dwellers, insectivorous and granivorous species in urban areas, with frugivores relegated to peri-urban sites, usually coinciding with avoider species. Natural peri-urban areas and intra-urban wetlands and urban parks were the most important refuges for birds and maintained the highest avoider and utilizer species richness. Long-term inventories are fundamental for determining consolidated bird diversity and distributional patterns. This information established a baseline for decision-making and applying recommendations that allow reconciling the growing demand for urban areas with the need to preserve the native avifauna in megadiverse Neotropical countries such as Colombia.