Evolution of Life Histories in Birds of Prey

At first sight, birds of prey may seem unsuitable study species because of their long lifespans, but the common buzzard ( Buteo buteo ) study has been running for 30 years. This not only permits analyses which are normally applied to much shorter-lived species but also enables us to test whether paradigms set by the study of short-lived species apply to long-lived species as well or whether our understanding is biased by the few short-lived model organisms. Individual behaviour is bound to have cumulative effects at the population level and of course population density is bound to affect individual behaviour. Detailed individual-based data as well as population data are necessary to study these interactions.

The study on goshawks ( Accipiter gentilis ) now runs for 44 years and yields fitness data as well as population fluctuations which allow me to bridge the gap between individual behaviour and population dynamics. We were able to show that a very important life history trait such as age at first breeding is crucial for the fitness of the individual and that it is strongly mediated by habitat heterogeneity. This habitat heterogeneity also regulates the population dynamics. By integrating life history strategy research into population ecology, it is possible to gain a much deeper understanding of individual fitness as well as population phenomena.