A comparison of Goshawk summer diet in three areas with different breeding density in western Norway

Abstract

In Norway, Goshawk Accipiter gentilis populations have declined in continuously forested areas in the inland, possibly because of decreased populations of grouse. The highest breeding densities are now found in landscapes dominated by farmland and urban areas, and in some areas close to the coast. In western Norway, we have compared the summer diet of Goshawks breeding at high densities in one island area and one urban area with that of Goshawks breeding at lower densities in an inland area at higher altitudes, approximately 90 km from the coast. Birds dominated the diet in all areas, but the diet diversity was lower in the inland than in the two other areas. The number of pigeons, Woodcock Scolopax rusticola and ducks/waders found at nest sites decreased with altitude, whereas the number of grouse increased. We conclude that Goshawks in the inland are more dependent on grouse because of lower availability of alternative prey.