Resource use and associated energy expenditure of African crowned eagles (Stephanoaetus coronatus) in an urban-forest mosaic landscape.

Rapid urbanization is a major driver of global change, making it increasingly important to understand how wildlife persists in highly transformed landscapes. Using insights from movement (Global Positioning System, GPS) and activity (accelerometry, ACC) data, we aimed to understand the behavioral and physiological mechanisms associated with an apex predator's successful exploitation of heavily transformed landscapes. The African crowned eagle (Stephanoaetus coronatus), a subtropical forest eagle, breeds at unusually high densities in Durban, eThekwini Municipality, South Africa. Here, crowned eagles inhabit an urban-forest mosaic, much of which falls within the Durban Metropolitan Open Space System (D'MOSS), a network of protected and semi-natural green spaces embedded within the city. Using data from five GPS/ACC-tagged crowned eagles, we assessed individual resource selection and determined how energy expenditure, inferred from overall dynamic body acceleration, varied across habitat types and with distance from the D'MOSS boundary. We found that crowned eagles selected forested habitats over built-up habitats when available. Energy expenditure was higher in built-up environments and increased with distance from the D'MOSS boundary. Our findings suggest that habitat structure may influence energy costs, although quantifying these relationships in heterogeneous urban landscapes remains challenging. We underscore the importance of protected habitat networks in cities and provide insights into the physiological costs of navigating urban-forest mosaic landscapes. These insights can inform urban planning to conserve natural habitat networks and ecosystem features that support the persistence of urban biodiversity, including apex predators.