Legal-environmental perspective on the studies of migratory avifauna in the preparation of wildlife expert reports for licensing: a literature review

The normative framework governing fauna constitutes an indispensable legal instrument for the protection of species at risk of extinction, as well as for the perpetuation of biodiversity and the safeguarding of ecological balances. In this context, environmental licensing emerges as a regulatory mechanism of considerable significance, as it establishes methodological guidelines for the assessment and approval of potentially impactful projects, in accordance with the principles of environmental prevention and precaution. The preparation of wildlife inventories, as a procedural requirement of these processes, demands from the project proponent the meticulous identification and systematic evaluation of the effects arising from their intervention in the natural environment, encompassing, inescapably, various taxonomic groups such as mammals, birds, reptiles, amphibians, and, when applicable, ichthyofauna in aquatic ecosystems. However, recurrent uncertainty arises regarding the determination of which species should be included in the inventory, particularly concerning migratory birds, whose biological peculiarities and cross-border movements introduce additional complexities to their proper classification and documentation. In light of this issue, the present study aims to conduct a bibliographic and normative review to examine the legal concept applicable to migratory birds, in accordance with Brazilian legal requirements and the obligations derived from international conventions ratified by the State. The investigation focused on analyzing the principal federal legal instruments, as well as subordinate regulations and administrative resolutions, which explicitly define or reference the categorization of migratory fauna. From this analysis, it was verified that, from a legal-environmental perspective, migratory birds are unequivocally and expressly considered part of the wildlife, meaning that their inclusion in environmental technical reports is not optional for the project proponent but rather a binding legal requirement. It is thus concluded that the incorporation of migratory birds into Wildlife Reports constitutes a sine qua non condition for the diagnostic effectiveness of these instruments, enabling not only the accurate identification of environmental impacts but also the proposal of mitigation and conservation measures capable of reducing or neutralizing potential damages, thereby ensuring compatibility between economic development and the preservation of natural heritage.