Epsilon Archive for Student Projects

Abstract

The Golden Eagle (Aquila chrysaetos) is an iconic bird of prey, widely distributed across the Northern Hemisphere. The versatility of the golden eagle has allowed them to inhabit a wide range of habitats, where adult eagles establish territories with their partner. Of the near 500 breeding pairs in Sweden, the majority inhabit the mountainous boreal landscapes of the north. However, the highest density of breeding pairs is concentrated on the island of Gotland in the Baltic Sea southeast of mainland Sweden. The island contains atypical habitats for golden eagles, characterized by flat landscapes, limited boreal forest, and widespread human presence. This study explored the underlying factors driving breeding ecology for golden eagles on Gotland. Temporal and spatial patterns of reproductive success were tested for correlation with habitat type, food supply, human disturbance, wind turbines, and con- and interspecific density dependency. A strong correlation was detected between temporal roe deer (Capreolus capreolus) abundance and number of occupied golden eagle territories. Territories with many nearby territories were correlated with higher reproductive success. Furthermore, reproductive success displayed weak but insignificant positive trends with coniferous forest, wind turbines and white-tailed eagle (Haliaeetus albicilla) presence, and weak negative trends with human disturbance and roe deer related traffic accidents. However, further studies are required to draw conclusions. To further increase our knowledge of this extraordinary sub-population, future research would benefit from exploring accurate movement patterns and habitat use of individual eagles, detailed dietary habits, and relative disturbance of human activities during different parts of the year.