Figure 1.
Map of the study area Planken Wambuis (20 km2; bold contour) and its surroundings in the central Netherlands, showing habitat composition (shaded=forested; unshaded=mainly heathland), and the distribution of goshawk territories (snapshot of the year 1990). During 1975–2000, goshawk population dynamics (territory occupancy, age and identity of breeders and non-breeders, reproductive performance, diet composition) and goshawk prey availability were investigated in detail in Planken Wambuis. During 1975–1990, the entire area (SW–Veluwe) was searched annually for moulted feathers to record emigration of hawks from the focal plot. In the later years, a ‘buffer zone’ of at least 1–2 km around Planken Wambuis was searched for feathers. For further methodological details, see text. Scale bar=1 km.