Biodiversity hotspots at a small scale: the importance of eagles' nests to many other animals.

Top-predators, including birds of prey, play an important role in ecosystems and are good bioindicators (Sergio et al. 2005). Links between the presence of predators and the overall biodiversity of a particular habitat mainly focus on trophic relationships (Roth and Weber 2008, Sergio et al. 2008b, Burgas et al. 2014). However, top-predators not only have food requirements, but also need to build large, safe nests (Danko 2007). The building and occupancy of such nests by birds of prey are of the greatest importance for several reasons. The nests are often used for many years, due to the huge costs in time and energy of their construction, that, at least theoretically, offer possibilities of their use by many other animals for feeding, roosting and as breeding sites (Konrad and Gilmer 1982, Jiménez-Franco et al. 2014).