O Comportamento de duas espécies de aves simpátricas no campus da UFJF: Turdus leucomelas e Turdus rufiventris

Abstract

Urbanization modifies the availability of resources and the structure of bird communities, creating a favorable scenario for studies on the coexistence of generalist species. The objective of this work was to analyze and compare the behavioral patterns and space use of the sympatric species Turdus leucomelas and Turdus rufiventris on the UFJF campus, focusing on the reproductive period. The hypothesis tested was that coexistence would be mediated by niche-sharing mechanisms that minimize direct competition. The results revealed a clear asymmetry: Turdus leucomelas was significantly more frequent (69.4% of records) and presented a greater behavioral repertoire, including the construction of 9 nests in artificial structures, active territorial defense, parental care, and courtship rituals. Turdus rufiventris (30.6% of records) focused predominantly on foraging (60%) and exhibited low reproductive activity, with only one nesting event recorded (reuse of a T. leucomelas nest). Coexistence appears to be mediated by a competitive hierarchy in which T. leucomelas acts as the dominant species, actively appropriating urban niches through nesting plasticity and high territorial investment. Turdus rufiventris, in turn, coexists through a strategy focused on foraging and less temporal overlap in reproductive activities. The study concluded that coexistence on campus is mediated by a combination of mechanisms, confirming the hypothesis of niche sharing, but under a clear competitive hierarchy. The Rufous-bellied Thrush proved to be dominant and more successful in appropriating urban niches, thanks to an integrated adaptive package: nesting plasticity, high parental investment, and territorial behavior. The Rufous-bellied Thrush possibly coexisted through a greater focus on foraging, less reproductive activity during the period, and, when necessary, aggressive reactivity in specific contexts.