Simulating wintering destinations based on seasonal climate tracking
To simulate species’ migratory connectivity based on optimizing population tracking of climatic conditions throughout the year, we selected for each breeding ecoregion occupied by the species the wintering ecoregion occupied by the species that is the most similar in terms of climate. We estimated climate similarity as the distance between the mean climate of the ecoregions based on two-dimensional climate, temperature only and precipitation only. For each population, we kept the empirical breeding destinations (i.e. ecoregions occupied by the population during the breeding season) and the model generates a simulated set of occupied ecoregions during the wintering season. Climate was extracted and seasonal niche overlap was calculated in the same way as for the observed wintering distributions.