Poisoned baits drive record golden eagle mortality in northern Greece: A call for urgent conservation actions

Abstract

Despite an overall recovery of European large raptor populations, the golden eagle (Aquila chrysaetos) population in Greece is Endangered. Poisoning from baits set illegally for carnivore control is known as an important mortality factor, impacting a wider avian scavenger assemblage in our study area. We analysed golden eagle mortality data from northern Greece for the last 35 years, including the fates of 29 satellite-tagged individuals from the last decade. Poisoning accounted for 65 % of the overall mortality, the highest percentage recorded globally for any eagle population. Known fate survival models from telemetry data revealed 0.78 and 0.85 annual survival rates for immature and adults, respectively (the lowest reported in telemetry studies), improving markedly when censored for poisoning mortality. Poisoning occurred disproportionally close to protected areas, more often in areas with high carnivore livestock depredation and almost exclusively in winter when eagles were more likely to scavenge. Golden eagles were usually poisoned by directly feeding on carcasses and offal baits laced predominantly with illegal toxic substances (e.g. carbofuran and methomyl). Electrocution was the second cause of mortality, and collision with turbines was also recorded. The main conservation implication of our findings is that urgent policy changes are required to reverse the population's decline, mainly against the illegal use of poisoned baits and across prevention, legislative and enforcement levels. We propose specific measures towards this direction, such as improving livestock husbandry, further capacity building for wildlife crime investigation and reforms in relevant legislation.