Ornitología Neotropical

OCCURRENCE AND DIET OF THE THREATENED WHITE-WINGED COTINGA XIPHOLENA ATROPURPUREA IN THE NORTHERN ATLANTIC FOREST, BRAZIL

2025-02-28T07:27:12+00:00

The White-winged Cotinga Xipholena atropurpurea is a threatened species endemic to the Brazilian Atlantic Forest, with a restricted distribution in a few forest fragments. In this study, we report the discovery from field surveys of a new occurrence site for the species, after nearly 10 years since its last record in Paraíba, Brazil. We also collected occurrence, vegetation type, and dietary data from records in citizen science platforms, and modeled density of species records across its distribution. Our results revealed a density of occurrence records in areas where the species had previously been considered probably extirpated. We found more records in open ombrophilous forests and records of fruit consumption predominantly from the Araliaceae family. Our records provide insights into the species' current distribution in the Pernambuco Endemism Center region. We recommend establishing conservation units in the newly identified occurrence site, requiring monitoring and additional studies to aid future conservation efforts.

WATERBIRD ANNUAL ASSEMBLAGE IN A ZONE OF THE VENEZUELAN LLANOS REGION

2025-02-18T05:12:43+00:00

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 agro-forestry 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.

INTERSPECIFIC FEEDING BY A RED-NECKED TANAGER TANGARA CYANOCEPHALA PAIR TO VIOLACEOUS EUPHONIA EUPHONIA VIOLACEA NESTLINGS

2025-12-15T13:59:29+00:00

Interspecific feeding, the provisioning of young of another species, is a rare, non-adaptive behavior in birds. On 22 February 2025, during a birdwatching trip to the Parque Nacional da Tijuca, in the city of Rio de Janeiro, Brazil, A. Rayegani detected a Violaceous Euphonia Euphonia violacea nest. He observed the nest for 0.5-2 h on four days over a 14-day period. On 22, 26, and 28 February 2025, both the Euphonia parents and a pair of Red-necked Tanagers Tangara cyanocephala fed the three Euphonia nestlings at the nest entrance. This non-adaptive feeding by the tanagers may have been caused by the loss of their eggs or nestlings, which triggered the transfer of their misplaced parental instincts onto the Euphonia brood. Our observation is the first report of interspecific feeding in the tropics that did not involve brood parasitism and contributes to our knowledge of this non-adaptive behavior in Neotropical birds.