GLOBAL PATTERNS IN SPECIES RICHNESS OF PELAGIC SEABIRDS - THE PROCELLARIIFORMES

Quantitative information on large scale spatial patterns of biodiversi ty remains poor, especially for pelagic systems. In this paper the reg ional diversity of procellariiforms is mapped worldwide at the species level. These seabirds do not display a conventional latitudinal gradi ent of decreasing species richness towards high latitudes, but rather are most speciose between 37 degrees and 59 degrees S in all ocean bas ins. Based on data for foraging ranges, areas with the highest species richness and the most species with smaller range sizes are all found in the vicinity of New Zealand and its sub-Antarctic islands. In contr ast, data for breeding ranges show islands in the southern Indian and Atlantic oceans to have the highest number of breeding species, while these islands and New Zealand have the most species with smaller range sizes. No northern hemisphere regions are amongst the top ten grid ce lls for foraging and breeding species richness, although Hawaii has th e highest species richness of procellariiforms north of the equator. N orthern Baja California, Madeira, the Canary islands, and the west coa st of South America are all important sites of narrow endemism in the northern hemisphere. High species richness and narrow endemism coincid e with areas of significant longline fishing activity in the southern hemisphere. Near-minimum sets based on one and three representations d emonstrate that if all procellariiform species are to be retained, lar ge areas of the ocean and almost all breeding sites require conservati on.