Different objective, same mechanism, and unforeseen consequences: Insights into a pioneering species introduction for conservation

The introduction of exotic species to new habitats has been a historical human practice, ranging from utilitarian benefits to conservation efforts. This phenomenon has intensified over time, resulting in unexpected ecological and socio-economic impacts on receiving ecosystems. The case of the North African aoudad (Ammotragus lervia) introduction in the SE Iberian Peninsula in 1970 illustrates the multifaceted consequences and complexities associated with species introduction. Aoudad's introduction can be contextualized in four categories regarding socio-economic and ecological contexts, such as assisted colonization, hunting interest, taxon substitution, and trophic rewilding. Initially, the establishment of the species was promoted, and its growth favoured. However, its expansion along with ecological and socio-economic impacts led to conservation conflicts and impacts on human activities. Over the last two decades, aoudad management has shifted focus to active population control to mitigate ecological and socio-economic risks. Such species introductions highlight the challenge of predicting ecological and socio-economic outcomes, given the limited understanding of complex ecosystem dynamics and social context changes. Recent propositions regarding conservation strategies involving species introductions must heed the lessons from the aoudad case. The aoudad case emphasizes the importance of applying precautionary principles in species introductions, given the potential for irreversible consequences posed by established populations of introduced species.