Breeding populations and diets of the sparrowhawk Accipiter nisus and the hobby Falco subbuteo in the Wigry National Park (NE Poland)

Abstract

In 1990-1995, 12-15 pairs of Sparrowhawks (9.1/100 km2) and 7-9 pairs of Hobbies (5.6 pairs/100 km2) inhabited the forest-lakeland area of the Wigry National Park (NE Poland). The diet composition of the two species was studied by the analysis of pellets and prey remains. Sparrowhawks fed on birds (97% of prey items, 99% of food biomass), especially Turdus spp., Parus spp. and Fringilla coelebs. Hobbies consumed birds (52% of prey, 94% of biomass) and insects (43% of prey, 1% of biomass). Sparrowhawks specialized in forest birds, positively selecting Parus spp., Turdus spp., Picidae and Ficedula spp. Hobbies hunted mainly birds of open habitats (Alauda arvensis) and woodland (Anthus trivialis).