First arrival dates of birds to their breeding grounds can be a valuable biological trait reflecting global and local climate changes. Long-term trends in the first arrival dates of 28 common breeding bird species to Gułowskie Forests (eastern Poland) were studied for the period of 1970-2009. Only 6 species studied – Barn Swallow (18 days), Thrush Nightingale (28 days), Lesser Whitethroat (8 days), Golden Oriole (7 days), Common Blackbird (13 days), and Chaffinch (14 days) – demonstrated a statistically significant trend of earlier arrival. Short- and medium-distance migrants arrived significantly earlier (median date: March 22) than studied long-distance migrants (median: April 23).