The near extinction of two large European predators: Super specialists pay a price

Despite recovery plans, the Spanish Imperial Eagle (Aquila adalberti) and the Iberian lynx (Lynx pardinus) are in danger of extinction. These two flagship species tend to occur in pristine Mediterranean forests, and both prey preferentially on the rabbit (Oryctologus cuniculus). Spanish lynxes and eagles have sister species in continental Europe, the Eurasian lynx (Lynx europaeus) and the Eastern Imperial Eagle (A. heliaca), respectively. Recent genetic evidence indicates that these two pairs of species started to diverge from their ancestor species slightly less than 1 million years ago, when the longest-lasting Pleistocene glaciations covered Europe. We hypothesize that the Iberian lynx and the Spanish Imperial Eagle emerged as separate species in the Pleistocene refugia of southern Spain, where they hunted yet another locally evolved species, the rabbit, on which they have become dependent for survival. Two large predators that emerged at the same time may go extinct simultaneously because of their inability to shift to alternative prey. Many other relict species, including numerous species from oceanic islands, have naturally small populations because of evolutionary constraints and are permanently threatened with extinction. Recovery plans aimed at putting these species out of danger are unrealistic, as their populations are and have been chronically scarce. We suggest that what these species need are maintenance plans designed to buffer population declines due to either stochastic or human-induced events. A metaphor for this would be "emergency care units" for conservation.