Archived 2012-2013 topics: White-capped Albatross (Thalassarche steadi): uplist to Vulnerable?

BirdLife Species Factsheet for White-capped Albatross White-capped Albatross Thalassarche steadi has been listed as Near Threatened (approaching the thresholds for Vulnerable under criterion A2de, A3de, A4de) since 2007, when Diomedea cauta was split into Thalassarche steadi and T. cauta. The population trend of this species is poorly known. It is categorised as Near Threatened because, given its longevity and slow productivity, and a high rate of mortality recorded in longline and trawl fisheries, it is suspected to be declining at a moderately rapid rate (approaching 30% over 69 years). In part this reflects the fact that the species is characterised by high interannual variation in pairs breeding at colonies and may be a biennial breeder. Restricted to New Zealand as a breeder, the vast majority of birds nest on Disappointment Island (91,500 pairs in 2008, ACAP 2011), with c.5,200 pairs on Auckland Island, and an additional 100 or so pairs at Adams Island, all in the Auckland Islands group; and 20 pairs on Bollon’s Island in the Antipodes Island group. The geographic range of T. steadi brings it into contact with a variety of longline and trawl fisheries in New Zealand, the high seas and off the coast of South Africa and Namibia (Baker et al. 2007).  It has been estimated that the annual mortality of White-capped Albatrosses was over 8,000 over the period 1998-2005, 75% of which was as a result of interactions with trawl fisheries in South African, Namibian and New Zealand waters (Baker et al. 2007). The Auckland Islands squid trawl fishery killed 2,300 adults in 1990 alone, most through collision with net monitor cables, which were phased out in 1992 (Croxall and Gales 1998, Taylor 2000). However, birds are still killed by entanglement in nets and by collision with warp cables in trawl fisheries (Taylor 2000, Baker et al. 2007). This species is also the most frequently caught species in pelagic tuna longline operations off South Africa, with an estimated 7,000-11,000 killed between 1998-2000 (Ryan et al. 2002). In the South African demersal trawl fishery, observer data from 2004-2005 produced an estimate of 7,700 shy type albatrosses killed annually. Subsequent DNA analysis indicated that these were all T. steadi (ACAP 2011). In 2005 and 2006, T. steadi spent 85% of their time in southern African trawl grounds (ACAP 2011). Since the introduction of mandatory permit requirements in August 2006, whereby all vessels must deploy a bird streamer line, the bycatch rate has decreased, but further data collection is required to establish a new catch estimate (Watkins et al. 2006). The impact of the large distant water fleets of Japan, Taiwan (China) and Korea on T. steadi is largely unknown, but Japanese data from 2001-2002 indicate that at least 10% of recorded albatross mortalities were ‘shy-type’ albatrosses (Baker et al. 2007). Commercial exploitation of squid or fish reserves in Bass Strait could pose a threat to the species in the future by direct competition for food. On Auckland Island, the nesting area was significantly reduced during 1972-1982 because of interference by pigs, and feral cats may also take small numbers of chicks (Croxall and Gales 1998, Taylor 2000, Thompson and Sagar 2006). Population estimates prior to 2006 are not based on comparable methodologies, making it impossible to calculate population trends prior to that time. Since 2006, consistent survey methods have allowed greater comparability, with breeding numbers on Disappointment and Auckland Island estimated by aerial photography. Combined estimates for both islands (W. Misiak in litt. 2012) are: 2006/2007 = 117,197 pairs 2007/2008 = 90,866 pairs 2008/2009 = 96,958 pairs 2009/2010 = 74,730 pairs 2010/2011 = 77,005 pairs A TRIM model fitted to these data suggests a population decline of 9.8% per year (W. Misiak in litt. 2012). This five year period is too short to extrapolate to a reliable population trend estimate over three generations (69 years). However, even if the actual decline rate was as low as 2.5% per year, then the species would qualify as Critically Endangered under criterion A4ade (extremely rapid population decline),  providing the declines were projected to continue. If the decline was 1% per year or more then the species would qualify as Endangered, and a decline of 0.5% per year or more would qualify the species as Vulnerable. The uncertainty over the validity of extrapolating data from a five year period over 69 years, coupled with further uncertainty caused by high interannual variation in breeding numbers, suggests that a precautionary estimate of a rapid ongoing population decline (30-49 % over 69 years) may be more appropriate until a longer period of counts are available to enable better projection of long term trends. Since the primary driver of declines is assumed to be fisheries bycatch, and given the reported bycatch figures, declines may be suspected to have been taking place for some time prior to the current series of counts. Thus, a decline of 30-49% over a 69 year period commencing in 1980, and uplisting to Vulnerable, is precautionarily proposed. If so, it would be important to pinpoint when the rate of population decline is thought likely to have first exceeded 30% over three generations (was this prior to, or since 1988?). Comments are invited on whether uplisting to Vulnerable is appropriate given the data available and the likely threats to the species. Thalassarche steadi trend analysis References ACAP 2011. ACAP Species assessment: White-capped Albatross Thalassarche steadi. Downloaded from on 22 March 2013. Baker, G. B.; Double, M. C.; Gales, R.; Tuck, G. N.; Abbott, C. L.; Ryan, P. G.; Petersen, S. L.; Robertson, C. J. R.; Alderman, R. 2007. A global assessment of the impact of fisheries-related mortality on Shy and White-capped Albatrosses: conservation implications. Biological Conservation 137(3): 319-333. 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. Ryan, P. G.; Keith, D. G.; Kroese, M. 2002. Seabird bycatch by tuna longline fisheries off southern Africa, 1998-2000. South African Journal of Marine Science 24: 103. Taylor, G. A. 2000. Action plan for seabird conservation in New Zealand. Department of Conservation, Wellington. Thompson, D. R.; Sagar, P. M. 2006. Conduct a population and distributional study on White-capped Albatross at the Auckland Islands. Watkins, B. P.; Petersen, S. L.; Ryan, P. G. 2007. Interactions between seabirds and deep-water hake trawl gear: an assessment of impacts in South African waters

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3 Responses to Archived 2012-2013 topics: White-capped Albatross (Thalassarche steadi): uplist to Vulnerable?

  1. Igor Debski says:

    Results from further aerial surveys at the Auckland Islands in 2011/12 and 2012/13 are now available:
    These more recent surveys vary in timing by one month compared to the earlier surveys, and introduce some issues with comparability, as a greater number of non-breeding birds were encountered. Total estimates of annual breeding pairs, adjusted for non-breeders, now give the following time series:
    116 025, 90 036, 96 118, 73 838, 76 119, 92 692 and 100 501 for each year from 2006 to 2012.
    Whilst a TRIM analysis of this time series still finds a moderate decline, trend analysis using smoothing splines, which is more appropriate to such data sets, showed no evidence for systematic monotonic decline over the 7 years of the study.
    Further details can be found in the report.

  2. At its last meeting in April 2013, the ACAP Population and Conservation Status Working Group recognised that the data in PCSWG Doc 04 (and text above) represented a persuasive case for up-listing to Vulnerable. However, Igor Debski (New Zealand) informed the meeting that the two latest aerial photographic censuses suggest that the breeding population may be substantially larger than anticipated from counts in preceding years, which may indicate a lower rate of decline or even stability. Further analyses will be available in June 2013, and Dr Debski was encouraged to submit these to the BirdLife Discussion Forum.

  3. Barry Baker says:

    As lead author of the report (Baker et al 2013) referred to in Igor Debski’s comments, I confirm that that aerial surveys in 2011 and 2012 have produced estimates of annual breeding pairs that approach those recorded in 2006. While the estimates provided by Igor have been controlled for the presence of non-breeding birds, the impact of breeding failures that would most certainly have been incorporated in the last two year’s estimates, has not been addressed. This is because we had no information on which to base such an adjustment. From 2006 to 2010 flights were conducted in mid December to coincide with the early incubation period of the breeding cycle. At this time it was anticipated that birds would have just completed egg laying (M. Double unpublished; P. Sagar unpublished), and hence most birds that attempted to breed would still be attending active nests. For logistical reasons the flights for the 2011 and 2012 counts were undertaken on 11 January 2012 and 14 January 2013, respectively. This timing was not ideal with respect to the breeding cycle of white-capped albatross, as although hatching would not have commenced, some nests could be expected to have failed and those breeding birds may have abandoned their breeding sites. The level of nest failure in this species is currently unknown, but had the 2011 and 2012 surveys been carried out earlier, the estimates for these years would have almost certainly been higher, and perhaps considerably (c. 10%) higher. Given that the trend analysis using smoothing splines showed no evidence for systematic monotonic decline over the 7 years of the study, and therefore providing support to the null hypothesis of no trend (stability) in the total population, I don’t believe changing the conservation of this species at this stage is warranted.

    Francis (2012) recently conducted a PVA for this species and concluded the population status to be uncertain. This assessment was carried out before our 2011 and 2012 estimates were available. While I don’t necessarily support all of the conclusions of this paper (see Baker et al 2013) it is valuable in that it contains estimates of bycatch (including cryptic mortality), adult survival, annual probability of breeding and breeding success. These data may be useful in contributing to assessment of population status. For example, I think the estimated annual adult survival (0.96, 95% confidence interval of 0.91–1.00) provides good evidence that adults are not being overly impacted by fisheries bycatch.

    Baker, G. B., Jensz, K., and Cunningham, R. 2013. White-capped albatross population estimate — 2011/12 and 2012/13. Final Report prepared for the New Zealand Department of Conservation, Contract 4431 & Project POP2012-05. Latitude 42 Environmental Consultants, Kettering, Australia. Downloaded from on 4 August 2013.
    Francis, R.I.C.C. 2012. Fisheries risk to the population viability of white-capped albatross Thalassarche steadi. New Zealand Aquatic Environment and Biodiversity Report No. 104. Ministry for Primary Industries, Wellington, New Zealand. Downloaded from or, (go to Document library/Research reports) on 4 August 2013

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