Presented by Emilie Desjardins - Email: Emilie.Desjardins@uqat.caThe mining industry is believed to have negative impacts on ecosystems, including waterfowl. In Abitibi-Témiscamingue, a region in eastern Boreal Canada, wetlands and deep waters cover 43% of the 65, 000 km² and it is renowned for waterfowl diversity. Mining potential is also high, and the industry is very active, with 32% of the region claimed for mineral rights and numerous operating mines. Even if numerous avian species are frequently observed on certain mining sites, the diversity of species found on these sites is still poorly documented. Our project aims to determine to what extent mining sites can be considered breeding habitat for waterfowl as compared to natural sites. We compared 14 mining sites and 39 beaver ponds of similar sizes. We visited each site twice in summer 2018 and three times in summer 2019, in order to estimate occupancy and detection probabilities of different waterfowl species for two different life stages (broods and breeding adults). We also considered other habitat factors such as water pH, shoreline development index, pond area and water depth as predictors of the occupancy of these species. Preliminary analyses indicate that at least 12 species use mining sites during their breeding period. In 2018, the three most common species (Mallard, Ring-necked Duck and American Wigeon) showed no preference between beaver ponds and mining sites. In contrast, a fourth species, Common Goldeneye, was more likely to occur at mining sites. The occupancy patterns did not vary with any additional habitat variable we considered. In 2019, we will add new variables such as fish presence and vegetation cover to determine if they can explain site utilization by waterfowl. To date, this study suggests that some tailing ponds could be considered as high quality habitat for some waterfowl species.