This European eagle, the white tailed sea eagle (Haliaeetus albicilla), ranks among Europe’s largest birds of prey. A recent release near Pimiango in Asturias introduced nine sea eagles from Norway as part of a reintroduction effort aimed at establishing a breeding population along the Bay of Biscay.
The white tailed eagle is listed among the 13 animal species historically noted as extinct in Spain. Current regulations encourage public administrations to support the return of such species to their native habitats where feasible and safe.
However, secrecy surrounding the project and a perceived lack of robust scientific backing have drawn criticism from scientists, environmental groups, and livestock stakeholders alike.
How do reintroduction projects work?
The first well documented resettlement efforts began in the mid-19th century when the Swedish grouse was reintroduced in Scotland after disappearing in 1830. Since then, reintroduction has become a common tool in biodiversity conservation, though it remains controversial in some circles.
Reintroduction programs aim to reestablish species in areas where they have disappeared or to strengthen small, fragile populations. Sometimes species are introduced outside their historic range to restore ecological processes or to reduce extinction risk in certain cases, a concept sometimes called assisted colonization.
The goal of any reintroduction plan is careful evaluation. It is essential to determine whether the original causes of decline have disappeared and whether the release site can sustain a self maintaining population. Vitality analyses should consider food availability, breeding opportunities, and ongoing threats to survival in the area.
Ecological risks to other species and to ecosystem function must also be weighed. The release location should not compromise the integrity of the local environment or its resident communities.
Socioeconomic risks and public perception across different groups, along with financial considerations for ongoing management and potential mitigation measures, must be addressed before any release proceeds.
Examples in captivity in Europe show how carefully planned housing and handling can accompany releases and support monitoring efforts during acclimatization.
Declines or shifts in ecological communities reflect broader biodiversity challenges. When a species disappears, another may fill its ecological role, but adding a long absent or new species can alter existing interactions and lead to unforeseen consequences.
Is the sea eagle extinct in Spain?
Declaring a species extinct requires clear evidence of disappearance and the absence of ongoing records. In the case of the sea eagle in Spain, the evidence is not definitive. What exists are scattered reports, a few preserved specimens, and intermittent signs suggesting past presence, rather than settled confirmation of historical breeding in specific regions.
Early notes from the northern peninsula include a 1948 account by a local researcher referencing conversations with sailors and place names that could point to large birds. Those accounts do not definitively prove sea eagle breeding in Galicia, and the notion remains speculative. Earlier studies have mentioned sea eagle activity in other coastal areas, but those records are inconclusive and could reflect misidentifications with other large raptors such as ospreys, which do breed in the region.
Further analysis has questioned these claims, and the conclusion that a stable old population existed in Spain is not supported by consistent data. The project therefore centers on reintroducing sea eagles rather than rebuilding a presumed extinct native population.
Asturias has pursued a Pigargo project that rests on questionable historical evidence. Critics argue that the approach overlooks several prerequisites for a responsible release, including verifying historical reproduction, assessing impacts on other threatened species, and evaluating ecosystem balance in release zones.
The potential interactions with prey species such as the European shag or Atlantic salmon, which already face conservation challenges, require careful assessment. Breeding populations in western Iberia and the wider Bay of Biscay have shown declines in other contexts, underscoring the need for cautious planning. The consequences for livestock and domestic animals also warrant scrutiny, given varying regional experiences with large raptors elsewhere in Europe.
Wider conservation concerns persist. The Ría de Ribadesella Ría de Tinamayor Special Conservation Area for Birds, and other protected spaces, could be affected by the dispersal of released birds. Any planned activities in these zones should include comprehensive environmental assessments to anticipate broader ecological effects.
Several endangered species and habitats in the Cantabrian Mountains call for decisive conservation action. Some observers view the sea eagle releases in Asturias as misaligned with pressing conservation priorities and available funding.
As of late, a portion of the released eagles had been placed in acclimatization enclosures before release, with reports indicating ongoing activity and monitoring in the weeks that followed. Debates around the project continue, with analyses and commentary contributing to the broader discussion about ethical, ecological, and economic factors involved in such reintroduction efforts. Citations include The Conversation and researchers affiliated with the University of Oviedo.
End of article notes. The Conversation, 2022, offers context and counterpoints to the Pigargo initiative as part of a broader dialogue on reintroduction ethics and outcomes.