Black-browed Albatross, Thalassarche melanophris, ranges from subtropical to polar waters in the southern hemisphere (ACAP 2009). It breeds on islands throughout its circumpolar distribution, with breeding occurring on the Falkland Islands (Islas Malvinas), multiple islands to Chile, South Georgia (Georgias del Sur), Crozet and Kerguelen Islands (French Southern Territories), Macquarie, Heard and McDonald Islands (Australia) and Campbell and Antipodes Islands (New Zealand), with a colony also reported on Snares Island in 1986 (Croxall and Gales 1998, ACAP 2009). The Falklands Islands (Islas Malvinas) holds the largest number of breeding individuals (estimated at 475,500-535,000 pairs in 2010; Wolfaardt 2012). Most other breeding sites holding large numbers of breeding individuals are in Chile with 55,000 pairs estimated on Diego Ramirez in 2003, 58,000 pairs on Ildefonso in 2012 (Robertson et al. 2013), and 15,500 pairs on Diego de Almagro in 2002 (Lawton et al. 2003). The population size on South Georgia (Georgias del Sur) is difficult to estimate, but based on Poncet et al. (2006) and assuming the rate of decline was c.4% (similar to that of Bird Island), the population there may have been down to 56,000 pairs by 2012 (ACAP unpubl. data). However, this may be an underestimate as, based on surveys conducted in 2014/15 covering 30% of the South Georgia (Georgias del Sur) population, declines actually could have been at c.1.8% per year between 2005 and 2014 (Poncet et al. 2006, A. Wolfaardt in litt. 2016). The other populations contain an estimated 5,800 pairs (ACAP unpubl. data), giving a potential global population of c.700,000 pairs.
Surveys of the Falkland Islands (Islas Malvinas) population have suggested this population is on the increase, with a 2010 archipelago-wide survey revealing (through aerial and ground-based surveying) an annual increase of at least 4% between 2005 and 2010. This is supported by further aerial surveys from later in the 2010 breeding season and demographic data (Wolfaardt 2012). From this it has also been concluded that the population of Black-browed Albatross on these islands has likely increased since the first archipelago-wide survey in 2000, and potentially since the first ground-based surveys on Beauchêne and Steeple Jason islands in the 1980s. Chilean populations are also likely increasing, as work suggests that the Diego Ramirez and Ildefonso archipelagos (supporting c.85% of the Chilean population) increased by 52% and 18% respectively between 2002 and 2011 (or 23% for both sites combined) (Robertson et al. 2014). As stated above, though, the trend for South Georgia (Georgias del Sur) appears to be a decline. However, with the rate of decline better estimated, it appears that this population may not be declining as rapidly as previously thought.
With the Falklands Islands (Islas Malvinas) and Chilean populations making up the vast majority of the global population it is highly likely that this is currently increasing, and potentially has been since the 1980s. The species is currently listed as Near Threatened under criterion A4bd due to high levels of uncertainty that previously surrounded some trend estimates (see BirdLife International 2017). The generation length for this species is long (21.5 years), and data is not available to fully assess population trends over 3 generations into the past. However, given the newer information regarding trends in Chile and South Georgia (Georgias del Sur) it now seems unlikely that the species is in the process of undergoing a decline over 3 generations (commencing in 1980 and continuing into the future). The species would therefore no longer approach the threshold for Vulnerable under criterion A4 and would not warrant listing as Near Threatened under this criterion. The species’s very large range and population size also mean it would not approach the threshold for Vulnerable under any other criterion.
Therefore the proposal is that Black-browed Albatross be downlisted to Least Concern.
We welcome any comments regarding this proposed downlisting.
ACAP. 2009. ACAP Species Assessment: Black-browed Albatross Thalassarche melanophrys. Available at: #http://www.acap.aq/acap-species/download-document/1183-black-browed-albatross#.
BirdLife International. 2017. Species factsheet: Thalassarche melanophris. Downloaded from http://www.birdlife.org on 04/04/2017.
Croxall, J. P.; Gales, R. 1998. Assessment of the conservation status of albatrosses. In: Robertson, G.; Gales, R. (ed.), Albatross biology and conservation, pp. 46-65. Surrey Beatty & Sons, Chipping Norton, Australia.
Lawton, K.; Robertson, G.; Valencia, J.; Wienecke, B.; Kirkwood, R. 2003. The status of Black-browed Albatrosses Thalassarche melanophrys at Diego de Almagro Island, Chile. Ibis 145: 502-505.
Poncet, S.; Robertson, G.; Phillips, R. A.; Lawton, K.; Phalan, B.; Trathan, P. N.; Croxall, J. P. 2006. Status and distribution of Wandering, Black-browed and Grey-headed Albatrosses breeding at South Georgia. Polar Biology 29: 772-781.
Robertson, G.; Moreno, C.; Arata, J.A.; Candy, S.G.; Lawton, K.; Valencia, J.; Wienecke, B.; Kirkwood, R.; Taylor, P.; Suazo, C. 2014. Black-browed albatross numbers in Chile increase in response to reduced mortality in fisheries. Biological Conservation 169: 319-333
Robertson, G.; Moreno, C.; Lawton, K.; Arata, J.; Candy, S. G.; Valencia, J.; Wienecke, B.; Kirkwood, R.; Taylor, P.; Suazo, C. G.; Raymond, B. 2013. Black-browed albatrosses in Chile rebound in response to reduced mortality in fisheries. ACAP First Meeting of the Population and Conservation Status Working Group PCSWG1 Doc 03 Rev 1 Agenda Item 5.2.
Wolfaardt, A. 2012. An assessment of the population trends and conservation status of Black-browed Albatrosses in the Falkland Islands. Joint Nature Conservation Committee (JNCC), July 2012. Available at: http://www.epd.gov.fk/wp-content/uploads/An%20assessment%20of%20the%20conservation%20status%20of%20BBA%20in%20the%20Falkland%20Islands_July%202012_Final.pdf. (Accessed: 24/09/2013).