POPULATION SIZE AND TRENDS OF THE WAVED ALBATROSS PHOEBASTRIA IRRORATA

Albatross populations world-wide face a variety of anthropogenic threats, including fishery bycatch and contami-nant ingestion. Colony-based assessments of population size provide a necessary complement to studies of risks at sea to understand and minimize declines in albatross populations. We estimated the size of three components of the world population size of the Waved Albatross Phoebastria irrorata of the eastern Pacific Ocean in 2001. Adults that bred in 2000, but not in 2001, constituted 17.3 % of the population present at the main breeding site, Isla Española in the Galápagos Islands, while breeders and non-breeders constituted 22.3 % and 60.4%, respectively. The mini-mum estimate of the sum of these components ranged from 31 818 to 34 694 adults. An additional three adults were found on Isla de La Plata, and up to 11 adults were found as non-breeders on Isla Genovesa, Galápagos. In com-parison with a 1970 count on Española the overall population has changed little, but the breeding distribution has changed, apparently due in part to regrowth of vegetation after the eradication of feral goats Caprus hirca in 1978. RESUMEN Las poblaciones de Albatros alrededor del mundo enfrentan una variedad de amenazas, que incluyen la pesca incidental y la ingestión de contaminantes. Estimados del tamaño poblacional en las colonias son complementario