& centerdot; Many Neotropical birds, like the threatened, endemic Mexican Woodnymph Eupherusa ridgwayi, lack fundamental information on their breeding biology. Between 2021 and 2024, in March, July, and November, we discovered four nests of the Mexican Woodnymph in shade-coffee plantations and cloud forests in Nayarit, Mexico. These cup-shaped nests, mainly made of moss and fern, were built on understory branches, 1 m above the ground, on shady banks near roads or streams. Courtship involved males performing side-to-side and forward-backward flight. Three nests had two eggs (12.8 x 7.7 mm, N = 6 eggs) each. Two nests hatched two chicks each, but only one chick per nest survived. Nestling plumage became sexually dimorphic 17-20 days after hatching -an unusual trait for nestling hummingbirds. Chicks fledged on days 25-26 and remained nearby for 2 weeks. Our study quadruples the number of known nests and expands knowledge of nestling development, post-fledging care, and breeding season for the Mexican Woodnymph.
Little information exists on breeding biology of most Neotropical avian species, particularly for canopy nesting birds. We conducted observations of a Shining Honeycreeper Cyanerpes lucidus isthmicus nest from a 30-m canopy tower in tropical wet forest of southern Pacific Costa Rica. Over 26 days, from 4 February to 5 March 2025, we recorded nest visitation and attendance by the nesting pair and obtained the first photographs of the nest and nestlings for this species. The nest was a low cup, placed about 29 m high in the fork of a vertical twig of Coussapoa villosa. We recorded most nest visits from 06:00 h to 09:00 h, and only the female incubated. The two nestlings were provisioned mainly by the female, mostly with fruit pulp but also insects. Our observations contribute to knowledge on the breeding biology for a poorly-known species, permitting further meta-analysis to evaluate life-history theory for Neotropical birds.
& centerdot; Land-use change and urbanization are the main threats to biodiversity in tropical dry forest, but few studies have evaluated the influence on bird-plant interactions across a gradient of land-use conditions. In this context, we aimed to evaluate changes in richness and diversity of birds feeding on Bursera simaruba fruits in different land-use conditions of tropical dry forest in the Central Depression of Chiapas, Mexico. From December 2022-April 2023, when B. simaruba had mature fruits, we performed focal observations of birds feeding on fruits at each of 27 B. simaruba trees (8 h observation/tree), dispersed among three land-use conditions: wildlands, non-urban production systems, and urban. We recorded a total of 34 bird species (22 residents, 11 winter migrants, and 1 unidentified Empidonax species). Richness (q0) and diversity (q1) of birds consuming B. simaruba fruits differed significantly among land-use conditions, being significantly higher for trees in the non-urban production systems. Avian consumers of B. simaruba fruits were predominantly insectivorous, possibly due to the influence of the agricultural landscape. However, the majority of species consumed fruits as legitimate dispersers. Our results support the intermediate disturbance hypothesis, where species diversity is highest in sites with an intermediate degree of modification, thereby possibly having higher landscape heterogeneity than both low- and high-disturbance conditions. We also suggest that B. simaruba fruits are a key resource for birds, particularly in modified landscapes of rural or urban areas.
& centerdot; Knowledge of Nicaragua's Pacific slope seasonal tropical dry forest ecosystem and its avifauna remains limited, hindering effective conservation planning. To assess avian community composition and relative abundance, from 2009 to 2018 we conducted standardized monthly surveys in 147 point counts at 29 study sites along Nicaragua's Pacific slope. We also determined the influence of geographic, climatic, and landscape predictors on avian species richness and community similarity among sites. Overall, we documented 257 species at 29 study sites along the Pacific slope, including 17 species that were not previously reported, bringing the cumulative total known from the Pacific slope to 440 species, representing 57% of the country's avifauna. Species distributions exhibited strong geographic heterogeneity: Pacific-exclusive taxa predominated from Chinandega to Managua, whereas Caribbean-affiliated species peaked in Rivas. The geographic variable of elevation did not significantly influence overall species richness, but percent of forest-dependent species increased marginally with elevation, having highest densities in Rivas (70%) and Granada (17%). Landscape variables of tree cover and forest patch size were not associated with overall avian richness, but a larger forest patch size strongly predicted a higher percent of forest-dependent species, underscoring the importance of habitat contiguity. Biogeographic clustering further distinguished the northern and southern assemblages, with unique highland communities above 1000 m. These findings highlight the Pacific slope as a region of exceptional but uneven avian diversity, where the conservation of large, contiguous forest patches, particularly in montane zones, is critical for sustaining forest specialists, maintaining ecological connectivity, and safeguarding ecosystem services.
& centerdot; The Venezuelan Llanos is a floodplain region of global importance for waterbirds, but comprehensive surveys of waterbird assemblages that encompass the entire annual cycle are lacking. We conducted monthly fixed-point surveys of waterbirds at eight permanent lagoons within an agroforestry landscape in the Llanos over an entire annual cycle, from April 2022 to March 2023. We recorded species richness and abundance and evaluated diversity, dominance, turnover patterns, and spatio-temporal variation to characterize assemblages and assess the conservation value of these wetlands. We recorded a total of 54 waterbird species, with greatest species richness and abundance at the largest Samancito lagoon. Month of the year significantly influenced species richness and abundance, peaking during the dry season. Structural traits (diversity, dominance, and species turnover) varied among lagoons, reflecting distinct ecological values and assemblages, with certain lagoons serving as functional hotspots for specific guilds, such as Gandaria lagoon for waders. Migratory species comprised a modest percent of species richness and total bird counts, peaking in the month of September (20% species richness; 12% abundance). Our findings underscore that wetlands within the Venezuelan Llanos were not functionally uniform, including also temporal dynamics of waterbird assemblages. Conservation and management strategies should recognize the complementary roles of different wetlands and account for seasonal variability in species use, thereby preserving permanent wetlands to support waterbird assemblages year-round, particularly during resource-scarce dry season.
