Hybridization between Alpine Ibex and Domestic Goat in the Alps: A Sporadic and Localized Phenomenon?

SIMPLE SUMMARY: The Alpine ibex (Capra ibex) is a protected wild ungulate. The species is known to have a low genetic variability and to occasionally suffer from local population decline as a consequence of epidemic diseases. Another, less investigated, threat for the species’ long-term conservation is represented by the hybridization with feral domestic goats that may breed with ibex if abandoned in the mountain at the end of the summer pasture. Further reproduction and the spread of hybrids may jeopardize the genetic integrity of wild Alpine ibex. By means of an online survey and using a network of experts, we mapped unpublished evidence on observed hybridization events between Alpine ibex and feral domestic goats. The results of this study suggested that hybrids are currently distributed in several countries, and their presence is not a rare event, with some clusters including 4–20 probable hybrids. This calls for more studies clearly quantifying hybrids in Alpine ibex colonies, but also highlights the need for conservation actions aimed at controlling this phenomenon, such as the effective management of domestic herds grazing in Alpine ibex core areas and clear guidelines on hybrid management. ABSTRACT: The Alpine ibex (Capra ibex) is a mountain ungulate living in the European Alps. Although being currently classified as a species of Least Concern (LC) by the IUCN, a potential threat for its long-term conservation is introgression following hybridization with domestic goats (Capra hircus). Hybridization has been documented in Switzerland in captive and free ranging animals, although accurate data to assess the extent of this phenomenon in natural conditions in the Alps are lacking. Using an online survey and a network of experts, we collected and mapped unpublished evidence of hybridization events that occurred between Alpine ibex and feral domestic goats from 2000 to 2021. The results of this study showed that hybrids are distributed in most of the Alpine countries, and their presence is not a sporadic event, with some clusters including 4–20 probable hybrids. Our results illustrated the need for establishing a standardized and effective protocol to identify hybrids in the field (such as a formal description of the morphological traits characterizing hybrids), as well as clear guidelines for hybrid management. Even more importantly, this study also highlighted the need for actions aimed at avoiding hybridization, such as the effective management of domestic herds grazing in Alpine ibex core areas.