Ecologia trófica da avifauna do Ceará: uma abordagem integrada utilizando dados de ciência cidadã – Wikiaves

Abstract

Trophic relationships constitute the functional basis of ecosystems, regulating energy flow and nutrient cycling, and can be translated into essential ecosystem services such as pollination, seed dispersal, and biological pest control. However, in semi-arid regions of high biodiversity such as the Caatinga, including its humid enclaves, in northeastern Brazil, knowledge regarding the diet, trophic guilds, and interaction networks of avifauna remains incipient and fragmented, resulting in a severe Eltonian shortfall that limits the effectiveness of conservation strategies. The main objective of this study was to organize, analyze, and synthesize the feeding habits and trophic network structure of the avifauna of the state of Ceará, overcoming field logistical constraints through the exclusive and systematic use of data from the citizen science platform WikiAves. The methodology involved the manual and exhaustive screening of 107,869 photographic records, following a rigorous protocol adapted from the PRISMA model to ensure data reliability. A total of 2,420 records showing unequivocal evidence of natural feeding were included in the final matrix and categorized into consumers of plants, invertebrates, and vertebrates, excluding artificial interactions. The results demonstrated broad spatial coverage across 119 municipalities, with marked asymmetry in the sampling records concentrated in urban and montane areas, such as Fortaleza, Guaramiranga, and Potengi, contrasting with significant gaps in the central hinterland that require further attention and future sampling efforts. Trophic analysis revealed the predominance of invertebrates in the diet of most Passeriformes, whereas vertebrate predation exhibited distinct patterns of specialization and generalism, highlighting strict piscivory in Pandionidae, specialization on mammals by Tyto furcata, and trophic plasticity in Falconidae and Accipitridae. The bird–plant interaction network, composed of 763 connections, was strongly interconnected and asymmetric. Native resources, such as the stinging nettle (Cnidoscolus urens, 50 interactions) and cacti, remain structural elements of the network; however, a strong incorporation of exotic species was observed in the diet of generalist species, notably coral fountain (Russelia equisetiformis) and mango (Mangifera sp.). The discussion emphasizes the broad resource spectrum exploited by birds and the use of exotic resources as adaptive responses to climatic seasonality and landscape anthropization. Citizen science, when subjected to careful supervision, is an indispensable tool for elucidating species distributions and functional ecology at a macroscale, providing novel and robust support for species management, urban afforestation planning, and ecological restoration in Ceará.