Biologia de la conservació d'un ocell críticament amenaçat: la baldritja Puffinus mauretanicus

Resumen

The Balearic shearwater Puffinus mauretanicus is one of the most threatened seabirds in the Mediterranean. This article summarises the conservation problems in the two habitats they occupy: the breeding colonies on land and the feeding areas at sea. A detailed demographic analysis indicates that adult mortality is the principal cause of population decline. The low adult survival rate (0.78, SE = 0.02) in colonies free of predators suggests that, in addition to predation, there must be other sources of mortality (fishing gears, for example). The analysis of population viability shows that the probability of extinction for the Balearic shearwater is extremely high, classifying the species as Critically Endangered according to the criteria of the IUCN. With regard to its distribution at sea, by means of an analysis of the oceanographic habitat of this species during the breeding season, a marine protected area can be proposed. The areas of high density (mainly feeding zones) would determine the core, of special conservation interest for the species, where strict protection measures would be implemented: the area of influence of the Ebro river and the sea around the cap de la Nao. Elsewhere within the foraging range of the species (coastal waters of the Iberian continental platform characterised by frontal systems in areas close to breeding colonies), more diffuse protection measures could be applied.