Avian top predator and the landscape of fear: responses of mammalian mesopredators to risk imposed by the golden eagle

• Published in: Ecology and Evolution
• Main Authors: Lyly, Marie S., Villers, Alexandre, Koivisto, Elina, Helle, Pekka, Ollila, Tuomo, Korpimäki, Erkki
• Other Authors: Section of Ecology, University of Turku, Centre d'Études Biologiques de Chizé - UMR 7372 (CEBC), La Rochelle Université (ULR)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Finnish game and fisheries research institute (FINNISH GAME AND FISHERIES RESEARCH INSTITUTE), Finnish game and fisheries research institute, Finnish Forest and Park Services, Natural Heritage Services
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2015
• Subjects: Intraguild predation; mesopredator suppression; pine marten; raptor; red fox; trophic interactions; [SDE]Environmental Sciences; Aquila chrysaetos; golden eagle
• Online Access: https://hal.archives-ouvertes.fr/hal-01359473; https://doi.org/10.1002/ece3.1370

International audience Top predators may induce extensive cascading effects on lower trophic levels,for example, through intraguild predation (IGP). The impacts of both mamma-lian and avian top predators on species of the same class have been extensivelystudied, but the effects of the latter upon mammalian mesopredators are notyet as well known. We examined the impact of the predation risk imposed by alarge avian predator, the golden eagle (Aquila chrysaetos, L.), on its potentialmammalian mesopredator prey, the red fox (Vulpes vulpes, L.), and the pinemarten (Martes martes, L.). The study combined 23 years of countrywide datafrom nesting records of eagles and wildlife track counts of mesopredators inFinland, northern Europe. The predation risk of the golden eagle was modeledas a function of territory density, density of fledglings produced, and distanceto nearest active eagle territory, with the expectation that a high predation riskwould reduce the abundances of smaller sized pine martens in particular. Redfoxes appeared not to suffer from eagle predation, being in fact most numerousclose to eagle nests and in areas with more eagle territories. This is likely dueto similar prey preferences of the two predators and the larger size of foxesenabling them to escape eagle predation risk. Somewhat contrary to our predic-tion, the abundance of pine martens increased from low to intermediate terri-tory density and at close proximity to eagle nests, possibly because of similarhabitat preferences of martens and eagles. We found a slightly decreasing trendof marten abundance at high territory density, which could indicate that theresponse in marten populations is dependent on eagle density. However, moreresearch is needed to better establish whether mesopredators are intimidated orpredated by golden eagles, and whether such effects could in turn cascade tolower trophic levels, benefitting herbivorous species.