Earlier arrival of some farmland migrants in western Poland

A dataset consisting of observations on the first arrival dates (FAD) of 16 species of birds from a locality in western Poland during the period 1913-1996 is presented and analysed For 14 of the 16 species, there is evidence of a trend towards earliness in recent years. In the 1970-1996 period this trend was significant for Pied Wagtail, Wood Pigeon, Black Redstart and Barn Swallow, and marginally significant for a further four species: European Serin, Blackcap, Common Nightingale and Red-backed Shrike. Only two species showed the opposite trend in the 1970-1996 period: Lesser Whitethroat and Whinchat, of which only the former is (marginally) significant. The trend towards earliness was more pronounced for short-distance (European) migrants than for long-distance (African) migrants. Short-distance migrants generally displayed a correlation with spring temperatures in the breeding locality, a feature less obvious in the long-distance migrants.