HIGH-DENSITY AND DISTRIBUTION PATTERNS OF A RAVEN CORVUS-CORAX POPULATION ON AN OCEANIC ISLAND (EL-HIERRO, CANARY-ISLANDS)

Data are provided on the density and distribution of an oceanic island population of Ravens (El Hierro, Canary Islands). The density of both the breeding population (ca. 35 pairs/100 km2) and that censused from a vehicle (35 birds/100 km) is the highest recorded in island environments and the second highest in the species' entire distribution area. The high density is probably due to an abundant food supply and numerous suitable nesting sites. Relief and altitude influenced the distribution of breeding territories which showed a high level of constancy from one year to the next.