Epsilon Archive for Student Projects

Abstract

Renewable energy sources like wind energy are rapidly expanding in order to meet challenges of climate change. Wind energy is leaving a significant negative impact on wildlife through collision of birds and bats with operating wind turbines. Raptors are one of the many species exposed to this threat. Golden eagle (Aquila chrysaetos) is a long-lived raptor with slow reproduction rate. The species is listed as Near Threatened in Sweden and faces several threats, such as illegal persecution and collisions with trains and wind turbines. Knowledge of movement ecology and flight behaviour of Golden eagles is therefore essential for a successful management and conservation of the species, if we are to identify the causes of collisions and the spatio-temporal distribution of threats. Topography, wind, habitats and elevation have been suggested to impact on flight behavior for Golden eagles. I studied the movement ecology of Golden eagles by using data from 31 GPS transmitter equipped Golden eagles. Topographic and life history variables were used to explain the patterns of flight height using Generalized Linear Mixed Models (GLMMs). A combination of these factors including, wind speed and the habitat variables significantly affected the flight height, but overall model predictability was low. This calls for getting a deeper understanding on-site wind conditions and local weather. The flight height of marked birds within wind farm areas was higher than flight height further away from wind turbines. Home range analyses revealed that 60 % of the home range areas (95 % contour) contained operating wind turbines and 85 % of the home ranges contained proposed wind turbines, not constructed yet. Movement ecology in Golden eagles is likely to be affected by wind farms and it needs to be taken into account while planning construction of new wind farms.