1.7. Aim of this study

The main idea of this work is to declare the goshawk’s role in the population dynamics of grouse. Due to the interactive nature of the goshawk-grouse relationship, both participants are naturally affected. There have been two interesting processes in grouse dynamics: 6-7 year periodicity in the fluctuation and the long-term decrease in their numbers (Linden & Rajala 1981, Ranta et al. 1995). Because grouse are the main prey of goshawks in Finland, there is special interest as to how the goshawk has responded to these changes; dietary, numerically and evolutionary.