Crowned eagle nest sites in an urban landscape: Requirements of a large eagle in the Durban Metropolitan Open Space System

Abstract

Globally, dramatic land use change typical of urbanisation negatively affects biodiversity, especially for top predators. The Durban Metropolitan Open Space System (D’MOSS), South Africa, faces the challenge of conserving biodiversity in a regional hotspot in the face of rapid urban growth in one of Africa's major commercial hubs. Consequently, we investigated nest site selection of crowned eagles (Stephanoaetus coronatus) on various spatial scales within this urban mosaic. Unexpectedly the inter-nest distances were small in this human-dominated landscape. However, breeding sites were not evenly distributed through the landscape and were closely associated with natural forest, while nest trees were most frequently in patches of exotic large riverine Sydney blue gum (Eucalyptus saligna, Smith 1797) within the D’MOSS planning zones. Crowned eagles showed a strong tendency to avoid informal settlement areas; however they were tolerant of proximity to established formal settlements and occupied dwellings. Consequently, continued protection of the D’MOSS system, and a considered approach to management of E. saligna are necessary for the persistence of the crowned eagle in this landscape. Future research should focus on food requirements, post-fledging survival, and recruitment to determine which nest sites are most productive and whether this population is acting as a source or a sink.