Archived 2012-2013 topics: Black-footed Albatross (Phoebastria nigripes): downlist to Near Threatened?

BirdLife Species Factsheet for Black-footed Albatross Black-footed Albatross Phoebastria nigripes breeds on the Northwestern Hawaiian Islands (USA), the US Minor Outlying Islands and three outlying islands of Japan, colonies having been lost from other Pacific islands. The species is currently listed as Vulnerable on the basis of suspected rapid ongoing population declines over three generations (A4bd). It was previously listed as Endangered but was downlisted in 2011 (see archived BirdLife discussion forum). However, further analysis of population trend estimates for the species suggests that further reassessment as Near Threatened may be warranted. The analysis presented by Arata et al. (2009) concluded that the population is stable or increasing, although it may be at risk of decline in the future due to fisheries bycatch, with current bycatch levels approaching levels of Potential Biological Removal (PBR), the estimated maximum level of off-take possible without causing a decline. Other studies on this species have confirmed the impact of fisheries bycatch on survival (Verán et al. 2007) and the annual population growth rate (Niel and Lebreton 2005). Annual bycatch was estimated at 5,228 birds in 2005, which, if doubled to account for underestimation, approaches the maximum PBR level of 11,980 birds (Arata et al. 2009). The maximum PBR level for this species has previously been estimated at 8,850 birds per year (Niel and Lebreton 2005) and 10,000 birds per year (Cousins and Cooper 2000). There is also uncertainty over the historic population trends of this species. Monitoring data from three colonies in Hawaii, representing over 75% of the world’s population, suggested that numbers may have decreased by 9.6% from 1992 to 2001 (USFWS data per E. Flint 2003, Gilman and Freifeld 2003). However, linear regression analysis of log-transformed counts at the same colonies suggests that the species’s population has remained stable since at least 1957 and has increased overall since 1923 (Arata et al. 2009), while matrix modelling suggests that its population is currently stable or increasing slightly (Arata et al. 2009). In addition, trends over a three generation period (56 years) commencing in 1956 were estimated at +26% using TRIM to analyse data from ACAP (W. Misiak in litt. 2012). The lack of evidence for a population decline exceeding 30% over a three-generation period suggests that the species does not qualify as Vulnerable under A4, with a stable or increasing population suggesting it does not qualify under this criterion at Near Threatened either. However, the risk of bycatch approaching PBR and potentially leading to declines in future suggests that a precautionary listing of Near Threatened (under criterion A3d; ie a projected decline approaching 30% over the next 56 years) may be more appropriate. Presumably the species would also not have qualified at any higher category level since the date it was first assessed for the IUCN Red List in 1988. Comments on this assessment and the proposed downlisting to Near Threatened, plus any additional information on population trends, are welcomed. Phoebastria nigripes trend analysis References: Arata, J. A., Sievert, P. R. and Naughton, M. B. (2009) Status assessment of Laysan and black-footed albatrosses, North Pacfic Ocean, 1923-2000. U. S. Geological Survey Scientific Investigations Report 2009-5131. Reston, Virginia: U. S. Geological Survey. Gilman, E. and Freifeld, H. (2003) Seabird mortality in North Pacific longline fisheries. Endang. Spec. Update 20: 35-46. Naughton, M. B, Romano, M. D. and Zimmerman., T. S. (2007) A Conservation Action Plan for Black-footed Albatross (Phoebastria nigripes) and Laysan Albatross (P. immutabilis), Ver. 1.0. Niel, C. and Lebreton, J.-D. (2005) Using Demographic Invariants to Detect Overharvested Bird Populations from Incomplete Data. Cons. Biol. 19: 826-835 Verán, S., Gimenez, O., Flint, E., Kendall, W. L., Doherty, P. F., Jr. and Lebreton, J.-D. (2007) Quantifying the impact of longline fisheries on adult survival in the back-footed albatross. J. Appl. Ecol. 44: 942-953.

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One Response to Archived 2012-2013 topics: Black-footed Albatross (Phoebastria nigripes): downlist to Near Threatened?

  1. At its last meeting in April 2013, the ACAP Population and Conservation Status Working Group discussed the downlisitng of the Black-footed Albatross. The current status of this species was based on suspected rapid ongoing population declines over three generations (A4bd). More recent data and analyses suggest that the species does not qualify as Vulnerable under A4, nor as Near-Threatened, because of the stable or increasing population. However, modelling of the effects of bycatch in causing potential future population declines, suggests a precautionary listing of Near Threatened under criterion A3d, i.e., a projected decline approaching 30% over the next 56 years, might be more appropriate. A US review has recognised that Black-footed Albatross and Laysan Albatross are exceptional in that the vast majority of the world population nests on islands <10 m a.s.l. Recent models that consider dynamic wave action, rather than passive “bathtub” models of inundation, predict greater loss than anticipated of nesting habitat at lower values of predicted sea level rise for several important Black-footed Albatross breeding islands (Storlazzi et al. 2013; These more realistic models, in concert with accelerating sea level rise suggest repeated catastrophic reproductive failure in the future caused by loss of nest sites, resulting in population trajectories not easily predicted by current trends. This highlights the difficulty of incorporating climate change modelling into IUCN species listings using the current process.

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