The non-native African tuliptree, Spathodea campanulata (P. Beauv), is widely distributed in altered Neotropical environments, where hummingbirds are important pollinators. We investigated the assemblage of hummingbirds which fed on its nectar and described their behavior, to understand possible influences of the exotic tree on the territorial behavior in an altered environment in southeastern Brazil. Seven species fed on flower resources, mainly Eupetomena macroura (Gmelin, 1788), Amazilia lactea (Lesson, 1832), and Florisuga fusca (Vieillot, 1817). Visiting time was positive correlated with number of flowers accessed, but in most visits, hummingbirds get the nectar by pillage, instead of frontal access. Flower availability varied throughout months; however, we found no evidence of significative correlation between available flowers and number of agonistic encounters. Despite a high number of animal-plant interactions and a strong territorialism of some species observed in African tuliptree foraging site, there may be other plants at local scale influencing the behavioral patterns observed.

Human-wildlife conflicts pose significant challenges, requiring nuanced solutions rooted in ecological understanding and community engagement. In this sense, this opinion essay explores the first documented South American conflict scenario between Neotropic cormorants ( Nannopterum brasilianum ) and artisanal fisheries, located on Laguna Estuarine System, southern Brazil. Local reports converge on the information that, after 2015, Neotropic cormorants began to establish a reproductive colony on a non-breeders dormitory located at Noca Lagoon, near the estuary mouth. The colony’s consistent presence over the years and intense feeding activity, along with possible recruitment of cormorants, may lead to the perspective of increased population and nuances among fishermen. These concerns include vegetation suppression dealt by guano deposition, food competition, property damage, and fishery resources depletion. Despite no evidence of cormorant population increase and due the fact that fishing is an important regional activity, there was a response from local lawmakers to address this issue (Municipal Ordinary Law number 2.154/2020). The law imposes the harmful status to the native bird species and permit measures to “clean” harmful populations from properties. In addition, this law lacks control guidelines to cormorant populations, threating the local biodiversity and exacerbating the emerging human-wildlife conflict. To address these challenges, holistic and interdisciplinary approaches that understand cormorant behaviors and its interaction with fisheries activity are needed. From the knowledge bridge built from lawmakers, stakeholders, scientists, and fishermen, it is possible to foster dialogue and adopt a conceptual framework to mitigate conflict outputs and promote harmonious coexistence between wildlife and human activities.

Neotropic cormorants are abundant piscivorous birds in southern Brazil and present challenges for fisheries and aquaculture as potential food competitors. To evaluate this interaction, we address the species trophic overlap with artisanal fisheries in a productive estuary in southern Brazil (48°45’27’’S, 28°30’23’’W) with abundance data, pellet samples, taxonomic composition and fishery production during July 2021 until May 2023. Bird abundance showed a seasonal pattern with peaks during autumn-winter and a population decrease during spring-summer, primarily due to the migration of reproductive individuals and the establishment of a colony from March to September. Pellet analysis identified 31 prey types within 17 taxonomical families, most of which were fish from the Ariidae (35.9%), Engraulidae (15.6%), Scianidae (12.8%), Mugilidae (10.3%), and Gerreidae (10.1%) families. We characterized the cormorant population as opportunistic, as temporal variation and Amundsen’s analysis indicated the consumption of available and diverse resources. Through otolith-total length allometric regressions we estimated a mean fish biomass per pellet of 382.7g and prey size ranging from 26.6mm to 326.9mm. When compared to artisanal fisheries, cormorants consumed 12% the amount of fish exploited by artisanal fisheries during the sampling period, although the Pianka’s index of 0.78 indicated a high overlapping food resource. Cormorant predation on juvenile fishes likely plays an important ecological role at Laguna Estuarine System by regulating abundant prey species through density-dependent mechanisms. This study provides new and updated information on cormorant population, diet and interactions with artisanal fisheries of southern Brazil.