From the first observations to the recent establishment: the paradox of a sub-Saharan species colonizing the western Palearctic.

Abstract

Ongoing climate change is causing latitudinal shifts in many species to reach more favourable climatic conditions. These changes are of particular relevance in southern Europe, where a short-distance expansion of African species’ range toward the north represents a major step in biogeographical terms, as a new continent would be reached and colonised. In this way, species that were never in contact suddenly interacts with each other, generating changes in communities. This is currently occurring with Griffon and Rüppell's vultures in the Iberian Peninsula, where individuals of the African species are beginning to establish themselves on a stable basis in breeding colonies of Griffon Vultures. Until now, there has been no evidence that Rüppell's Vulture has been able to breed in Europe, despite some observed breeding attempts that did not result in successful reproduction. In 1999, an adult Rüppell’s Vulture was observed in Portugal in a possible nest, although successful breeding was not confirmed. The next signs of reproduction were detected in 2020 in southern Spain, when a female Rüppell’s Vulture was recorded mating with a male Griffon Vulture in Cádiz province, and a different female was observed carrying nesting material in Málaga province. Throughout 2021 and 2022, breeding attempts have consistently occurred in the breeding colony of Málaga, but close monitoring of the individuals, tagged with GPS transmitters confirmed that mating did not result in egg-laying. During the year 2023, the situation has changed and, in this communication, we will report the first confirmed case of Rüppell's Vulture breeding in Europe. Paradoxically, as the species begins to colonize a new biogeographic realm in the Palearctic, its rapid decline caused it to be reappraised to the IUCN Critically Endangered category. We will detail the case and discuss the potential implications for the conservation of the species.