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    Report on the status of wandering, black-browed and grey-headed albatrosses at South Georgia

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    Número de documento:
    S. Poncet (United Kingdom),G. Robertson (Australia), R. Phillips (United Kingdom), K. Lawton (Australia), B. Phalan, J. Croxall and P. Trathan (United Kingdom)
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    Surveys of all known breeding sites of wandering, black-browed and grey-headed albatrosses were carried out at South Georgia in the 2003/04 breeding season. Wandering albatrosses were censused by ground counts, and black-browed and grey-headed albatrosses mainly by yacht-based digital photography and subsequent counting on computer screen using Adobe Photoshop software. In total, an estimated 1,553 pairs of wandering albatrosses, 75,500 pairs of black-browed albatrosses and 47,800 pairs of grey-headed albatrosses were breeding at South Georgia in the 2003/04 season. Compared to results from a predominantly yacht-based survey of black-browed and grey-headed albatrosses over the whole of South Georgia conducted in the mid 1980s, numbers of these two species appear to have decreased by 26% and 14%, respectively. However, comparison of annual totals for Bird Island, which was censused on both occasions mainly by ground counts, indicate more rapid declines: 4.0% p.a. from 1989/90-2003/04 for black-browed albatrosses, and 2.9% p.a. from 1990/91-2003/04 for grey-headed albatrosses. Due to the lower accuracy of the methods used in the 1980s, it is likely that the Bird Island figures are more indicative of the population trends at South Georgia. The decline in wandering albatrosses is even more pronounced: 30% (1.8% p.a.) since the previous survey in 1984. The magnitude of these population decreases is alarming, given the long time span involved and consistent downward pattern. Of particular concern is the acceleration since 1997 in the rate of decline of wandering albatrosses at Bird Island, which now stands at 4.5% per year. Unless these long-term declines can be halted or reversed, there must be some doubt over the long-term viability of the breeding populations of these species of albatrosses at South Georgia.