Variação populacional de Fluvicola nengeta (Aves: Tyrannidae): comparação entre três períodos de monitoramento ao longo de 17 anos em um parque urbano no Triângulo Mineiro

Abstract

The species Fluvicola nengeta is a passerine bird of the Tyrannidae family, frequently associated with environments near rivers and lakes. It is a common species in Northeast Brazil, and its distribution has been expanding to Southern Brazil and other South American countries. This study aimed to evaluate possible differences in the abundance and frequency of occurrence of F. nengeta in Sabiá Park, Uberlândia, MG, over three sampling periods (2008/2009, 2014/2015, and 2024/2025). Furthermore, we sought to verify the existence of correlation between the abundance of records and the environmental quality of the sampled points, as well as to analyze the seasonal variation in the species abundance. For data collection, ten fixed points were established in the park, where abundance data were recorded during the three evaluated periods. The points were also classified according to environmental quality using macroscopic criteria. In the most recent period (2024/2025), 363 individuals were recorded, showing a 57.8% increase compared to 2008/2009 and stabilization compared to 2014/2015. The average monthly abundance differs significantly between periods, with a decrease in initial population growth followed by stabilization. No significant differences were observed in the frequency of occurrence or in the Point Abundance Index (PAI) between specific periods. A significant positive correlation was found between abundance and environmental degradation of the point, with a decrease in the species' occurrence at points with worse environmental conditions. No seasonal differences were detected between the dry and rainy seasons. The results show high ecological plasticity and population establishment within the park, with a strong association of the species with anthropized environments, demonstrating its potential as a bioindicator of degraded urban areas.