Golden Eagle dietary shifts following wildfire and shrub loss have negative consequences for nestling survivorship

Abstract Wildfires and invasive species have caused widespread changes in western North America’s shrub-steppe landscapes. The bottom–up consequences of degraded shrublands on predator ecology demography remain poorly understood. We used a before–after paired design to study whether Golden Eagle (Aquila chrysaetos) diet nestling survivorship changed following wildfires southwestern Idaho, USA. assessed burn extents from 1981 2013 vegetation between 1979 (pre-burn) 2014 (post-burn) within 3 km nesting centroids. measured the frequency biomass individual prey, calculated diversity indexes, monitored at 15 territories 1971–1981 2014–2015. On average, 0.70 area centroids burned 2013, mean proportion unburned shrubland decreased 0.73 0.22 2014. Diets post-burn years were more diverse had lower some shrub-associated species, such as black-tailed jackrabbits (Lepus californicus) mountain cottontails (Sylvilagus nuttallii), higher American Coots (Fulica americana), Mallards (Anas platyrhynchos), Piute ground squirrels (Urocitellus mollis), Rock Pigeons (Columba livia) compared with pre-burn years. A high waterfowl represented novel change diets, which are typically dominated by mammalian prey. Nestling was positively associated negatively eagle diets. vector for Trichomonas gallinae, disease-causing protozoan lethal young eagles. Nesting attempts likely fail (all die) period period. Dietary shifts common mechanism predators cope landscape change, but away preferred prey disease vectors affect could lead population-level effects productivity.