Predator-Prey Interactions Between Birds on Spring Migration Stopover in Forests at Hel Peninsula (N Poland) over 1982–2024

Climate change in Europe can influence the predator-prey interactions, a scarcely studied topic in birds. We examined relationships between the spring passage timing of the Eurasian Sparrow-hawk, a generalist peak predator, and its main bird prey species (Song Thrush, Blackbird, Chaf-finch, Great Tit, Robin). All six species were ringed daily during 26 March–15 May in 1982–2021 at the station Hel (N Poland). In 2024, we collected pluckings to identify Sparrowhawks’ bird prey. Sparrowhawks’ daily migration dynamics were correlated with those for the Song Thrush, Robin and Chaffinch. Sparrowhawks’ median (50%) dates of passage showed no multi-year trend, but large year-to-year changes, correlated with those of its prey, and with temperatures. Adult females and males migrated through Hel early after warm February and March at wintering grounds, re-spectively. Young males migrated early during warm Aprils at Hel. Median dates were positively correlated between adult males and Robins, and adult females and Blackbirds. This suggests that Sparrowhawks adjust their migration timing each spring to the availability of their prey, with some sex differences, as males are smaller than females. Identifying changes in predator-prey dy-namics for Sparrowhawk in response to climate change is crucial to understanding its effect on forest ecosystems.