Anthropogenic climate change affects all countries and so societies need to begin adapting to the ongoing impacts of these changes. In addition, different biomes respond in distinctive ways to climatic warming. For instance, like oceans, Arctic lakes are strongly affected by shorter ice-cover periods, further decreasing albedo which further increases warming. On the other hand, lakes located in Mediterranean regions are experiencing a decrease in the inundation area and water storage due to the magnitude of the droughts. It is important to say that inland waters are recognised as important sentinels of climatic change and their sediments accumulate records of past environmental conditions. For this reason, we can use these sediment records to study the trends in environmental changes such as warming or wet periods that occurred in the past. Through paleolimnological analyses, past climate history information can be inferred to determine the timing and degree of change in lake ecosystems. Whilst monitoring data may be short, the paleolimnological approach allows for the study of many years of a lake’s history in a very cost and labour effective manner. Furthermore, inland waters are frequently nesting areas for migratory birds, and these water bodies are especially sensitive to droughts. For this reason, waterbirds may suffer major losses by limited food supplies and habitat, as well as increased disease due to overcrowding. By using paleolimnological approaches, new methodologies allow us to assess past drought periods along with the long-term changes in bird population.This is why the main objective of this proposal is to study how past droughts and other climatic extremes have affected long-term dynamics of bird populations using paleolimnological approaches in two areas that are being affected by environment change in such different manners: ponds on nesting islands in the Great Lakes region of Canada and the Mediterranean Region of Spain.