Representatividade da Avifauna nas Unidades de Conservação do Maranhão

Abstract

Protected Areas (PAs) play a central role in biodiversity conservation in Brazil, particularly in ecologically complex regions such as Maranhão, where the Amazon, Cerrado, and Coastal–Marine domains converge. Despite the ecological relevance of this state, assessments evaluating the effectiveness of these areas in conserving avifauna remain scarce. This study aimed to analyze the representativeness of bird species within the Protected Areas of Maranhão, considering endemism, threat status, and the cumulative extent of protected area per species. A total of 4,004 occurrence records were compiled from citizen science platforms (WikiAves, eBird, Salve, and ARA) and the scientific literature. After taxonomic curation, 851 taxa were identified, distributed across 14 of the 45 Protected Areas present in the state. The structure of the PA network, species distribution, threat status (IUCN 2025; MMA 2025; SEMA–MA 2025), number of occupied PAs, and cumulative protected area per taxon were evaluated. Non-parametric tests were applied due to the non-normal distribution of the data (p < 0.05), and no statistically significant differences were detected at the 5% significance level. The results revealed a high diversity of species recorded within the Protected Areas, including 56 taxa endemic to Brazil and dozens of threatened species at the global (n = 24), national (n = 42), and state (n = 94) levels. However, only 14 of the 45 Protected Areas had occurrence records, indicating strong sampling asymmetry. A predominance of Sustainable Use Protected Areas was observed (76%). The representativeness of threatened and endemic species was low: no significant differences were detected in the number of Protected Areas occupied per taxon between threatened and non-threatened groups, and endemic species exhibited significantly smaller accumulated protected areas compared to nonendemic species. The Minimum Polygon Convexes (MPCs) indicated a concentration of records in a few Strictly Protected Areas and the presence of priority species outside protected boundaries. It was concluded that although Maranhão has extensive formal protected area coverage, its network shows limited capacity to adequately represent the most vulnerable avifauna. The main limitations identified include sampling gaps, a low proportion of Strictly Protected Areas relative to Sustainable Use Areas, lack of ecological connectivity, and underrepresentation of sensitive taxa. The findings reinforce the need to expand and strengthen conservation strategies, including the creation of ecological corridors, the integration of Indigenous Lands and Private Natural Heritage Reserves (RPPNs) into territorial planning, the expansion of priority areas, and the institutionalization of systematic monitoring programs.