iDNA-based mammal survey in the last large refuge of the giant armadillo in the Atlantic Forest

Abstract Sampling mammal diversity is effort-demanding in hyperdiverse biomes, such as the Atlantic Forest. Molecular tools for rapid biodiversity assessment, such as invertebrate-derived DNA (iDNA) metabarcoding, have emerged as promising approaches to complement traditional survey methods. Here, we assessed mammal diversity in a large Atlantic Forest remnant, Rio Doce State Park (PERD) in Minas Gerais state-Brazil, using iDNA metabarcoding from mosquitoes and flies during a short-term sampling effort. We evaluated the effectiveness of this method in detecting the mammal species expected to occur in the area, with particular focus on the giant armadillo Priodontes maximus , a rare and emblematic species known to inhabit the park. We detected more than half of the expected terrestrial mammal species despite the sampling window, a performance comparable to or exceeding previous iDNA applications in Neotropical forests. Similar overall mammal species richness were recorded in both dry and wet seasons; however, community composition differed, and detections per sampling point were higher in the dry season. Flies outperformed mosquitoes in total detections, although both samplers recovered complementary set of mammal species. Contrary to expectations, P. maximus was not detected in either season by any sampler. This non-detection may reflect its very low population density, potentially reduced attractiveness of its feces to insects, limited sampling window, or other constraints associated with DNA detection. Overall, iDNA metabarcoding proved effective for detecting diverse mammal assemblages and remains highly promising for expanding mammal monitoring in the Atlantic Forest and for assisting conservation efforts in one of the world’s most threatened biomes.