Not everything that glitters is gold : does linear infrastructure create an ecological trap for golden eagles?

• Main Author: Etienne, Michelle
• Format: Other/Unknown Material
• Language: English
• Published: SLU/Dept. of Wildlife, Fish and Environmental Studies 2020
• Subjects: HIREC; animal ecology; animal movement; animal behaviour; integrated step selection function; wildlife traffic accidents; maladaptive behaviour; fitness; habitat selection; Aquila chrysaetos; golden eagle
• Online Access: https://stud.epsilon.slu.se/15703/

Animals can be caught in an “ecological trap” when they select for seemingly attractive habitats at the expense of their fitness. This maladaptive behaviour is often a consequence of human induced rapid changes in their natal environment, such as the development of linear infrastructure, where roads and railways create novel feeding conditions through traffic induced mortality of other species and powerline areas provide perching or nesting sites. In this study strong indication is demonstrated that linear infrastructure creates an ecological trap for the golden eagle (Aquila chrysaetos). This is illustrated using integrated step selection function for habitat selection and movement behaviour with ten years of data from 74 GPS-tracked golden eagles in Sweden. Eagles show high mortality at road and railway sites, which increase habitat attractiveness by providing scavenging opportunities on casualties from wildlife traffic accidents, while powerlines provide perching sites. Eagles selected for these habitats all year round; immature eagles were more consistent in their selection of roads and railway sites in comparison to adults and show learning behaviour through an increased selection with age. I discuss implications of these findings for the conservation and population ecology of eagles and other scavengers.