Natal dispersal refers to the movement of an individual from its birth site to its first breeding site. The choice of a breeding habitat is critical for fitness, and the consequences can be lifelong if the species exhibits high fidelity to breeding sites. However, individuals selecting their first breeding site have no experience with the fitness prospects of different habitats and must, therefore, base their decision on other cues. Whether these cues are reliably linked to reproductive success in those habitats remains unclear.

In this thesis, I investigated natal dispersal and habitat selection of the white tailed eagle (Haliaeetus albicilla), a long-lived raptor with high breeding-site fidelity. Using a dataset of genetically and visually identified breeding individuals with known natal sites, I studied whether population density and habitat imprinting affect the settlement of white-tailed eagles, and whether these factors are associated with subsequent breeding success. I show that white-tailed eagles use conspecific density and natal habitat similarity as cues when choosing their breeding site. Eagles born in high-density areas tend to settle in lower-density areas in comparison, but dispersed over shorter distances. Breeding success was higher when the local breeder density was lower. White-tailed eagles also prefer their natal habitat type when choosing a breeding habitat, but this is not associated with improved breeding success. Since there were no effects of settling in natal-like habitats, this is likely a neutral behavioural pattern, or the benefits are gained in other ways. The habitat type seems to play a greater direct role in reproductive performance, since breeding success was higher in territories with a smaller proportion of water. I also found that older individuals seem to be more successful breeders than young ones.

The results shed light on the relationships between habitat selection mechanisms and the fitness prospects of chosen breeding habitats. Understanding these relationships is particularly important for long-lived species with high breeding site fidelity, such as large raptors. Many raptor populations are still recovering from past population declines or being reintroduced to their former range. Knowledge of the factors influencing movement and settlement can improve the success of reintroduction programmes and aid in predicting population growth and range expansion.