Autumn Migration Trends of Long- and Short-Distance Migrants in Central Eastern Europe (2012–2022): Patterns in Abundance and Timing

Long-term analyses of autumn bird migration in Central Eastern Europe remain scarce, particularly those based on standardised visual observations. We analysed 11 years of systematic counts (2012–2022) conducted by an experienced citizen scientist at a single site in northern Austria near the Czech border. The dataset comprises 5,411 quarter hours of observation from 6 a.m. to 12 a.m. between September and October, yielding 479,307 migrating individuals of 100 species. Migration intensity, measured as mean traffic rate (MTR), increased overall by 2% per year. This trend was driven by short-distance migrants (+3% annually), while long-distance migrants declined (–5% annually), with the steepest decreases in farmland species. Urban breeders showed moderate declines independent of migration strategy. Raptors increased markedly (+8% per year), primarily due to Common Buzzard Buteo buteo and Common Kestrel Falco tinnunculus. Phenological analysis revealed decreasing trends in September but increasing trends in October, indicating delayed departures for short-distance migrants and, unexpectedly, also for long-distance migrants, albeit at low abundance levels. Raptors showed consistent increases in both months. These findings demonstrate contrasting trends between migration strategies and breeding habitats, highlighting the role of different ecological pressures.