White-chinned Petrel (Procellaria aequinoctialis): uplist to Endangered?

This discussion was first published as part of the 2013 Red List update, but remains open for comment to enable reassessment in 2014.

BirdLife Species Factsheet for White-chinned Petrel

White-chinned Petrel Procellaria aequinoctialis is currently classified as Vulnerable under criterion A4bcde, as it is suspected to be undergoing a decline of 30-49% over three generations (74 years).

South Georgia (Georgias del Sur) holds an estimated 773,000 pairs (ACAP 2009), 64% of the global population of 1,200,000 pairs. Kerguelen Islands (French Southern Territories) held a further 186,000-297,000 pairs in 2005 (Barbraud et al. 2009), or  16-25% of the global total. The Auckland Islands (New Zealand) hold the next largest population, 100,000 pairs in 1988 (ACAP 2009).

Globally, population data and trends are still lacking or are uncertain for a number of colonies. However, burrow occupancy declined by 28% on Bird Island, South Georgia (Georgias del Sur) during 1981–1998 (Berrow et al. 2000). Declines of 86% were recorded at sea in Prydz Bay, Antarctica between 1981-1993 (Woehler 1996). Population monitoring at a study plot on Marion Island recorded a 34% decrease in the population between 1997 and 2000 (Nel et al. 2002). Data from the Crozet archipelago indicate a 37% decline in breeding pairs between 1983 and 2004, based on population models and field estimates from two surveys (Barbraud et al. in litt. 2008). Data from at-sea surveys suggest a 35% decline in the Southern Indian Ocean during 1981-2007 (Péron et al. 2010a). On Iles Kerguelen, available population count data do not show any trend: 100,000-300,000  pairs in 1987 (Weimerskirch et al., 1989) compared with 186,000-297,000 in 2005 (Barbraud et al. 2009), however Barbraud et al (2009) concluded that the population may be in decline, based on data from fisheries and a population model.

No population trend estimates are available from the Auckland, Campbell, Antipodes or Prince Edward Islands, together representing approximately 17% of the global population.

However, even if colonies on Auckland, Campbell, Antipodes, Prince Edward and Kerguelen are assumed to be stable, based on an ongoing -1.6% decline per year on South Georgia (ACAP 2012) and declines in the smaller population on Crozet, the overall global population is projected to decline by 52% over three generations from 1980 (see attached spreadsheet).  Martin et al. (2009) estimate a higher decline rate for South Georgia (-1.9% per annum), and if the population on Kerguelen was suspected to be declining then the rate of overall population decline could be higher.  This suggests that despite considerable uncertainty over the trend data, an uplisting from Vulnerable to Endangered may be warranted.

Comments are invited on the population and trend estimates for this species and their implications for its potential uplisting, as well as the likely timing of when the trend may have exceeded 50% over three generations.

Procellaria aequinoctialis trend analysis

References

ACAP 2009. ACAP Species Assessment: White-chinned Petrel Procellaria aequinoctialis. Downloaded from http://www.acap.aq on 22 March 2013.

Barbraud, C.; Delord, K.; Marteau, C.; Weimerskirch, H. 2009. Estimates of population size of White-chinned Petrels and Grey Petrels at Kerguelen Islands and sensitivity to fisheries. Animal Conservation 12(3): 258-265

Berrow, S. D.; Croxall, J. P.; Grant, S. D. 2000. Status of White-chinned Petrels Procellaria aequinoctialis Linnaeus 1758, at Bird Island, South Georgia. Antarctic Science 12: 399-405

Martin, A. R.; Poncet, S.; Barbraud, C.; Foster, E.; Fretwell, P.; Rothery, R. 2009. The White-chinned Petrel (Procellaria aequinoctialis) on South Georgia: population size, distribution and global significance. Polar Biology 32: 655-661.

Nel, D.C., Ryan, P.G., Crawford, R.J.M., Cooper, J., and Huyser, O.A.W. 2002. Population trends of albatrosses and petrels at sub-Antarctic Marion Island. Polar Biology 25: 81-89

Péron, C.; Authier, M.; Barbraud, C.; Delord, K.; Besson, D.; Weimerskirch, H. 2010. Interdecadal changes in at-sea distribution and abundance of subantarctic seabirds along a latitudinal gradient in the Southern Indian Ocean. Global Change Biology 16: 1895-1909

Weimerskirch, H.; Zotier, R.; Jouventin, P. 1989. The avifauna of the Kerguelen Islands. Emu 89: 15-29

Woehler, E. J. 1996. Concurrent decreases in five species of Southern Ocean seabirds in Prydz Bay. Polar Biology 16: 379-382

Related posts:

  1. Archived 2012-2013 topics: Grey-headed Albatross (Thalassarche chrysostoma): uplist to Endangered?
  2. Archived 2012-2013 topics: Rufous Crab-hawk (Buteogallus aequinoctialis): uplist to Vulnerable?
  3. Archived 2010-2011 topics: Collared Petrel (Pterodroma brevipes): uplist to Vulnerable?
  4. Archived 2012-2013 topics: White-capped Albatross (Thalassarche steadi): uplist to Vulnerable?
  5. Archived 2012-2013 topics: Macaroni Penguin (Eudyptes chrysolophus): correctly listed as Vulnerable?
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6 Responses to White-chinned Petrel (Procellaria aequinoctialis): uplist to Endangered?

  1. At its last meeting in April 2013, the ACAP Population and Conservation Status Working Group recognised that a change in status of this species would depend largely on the situation at South Georgia (Islas Georgias del Sur), which represents a substantial proportion of the global population. The WG noted the need for an updated assessment of this population prior to any change in status. In the meantime, it was suggested that its status as Vulnerable be maintained.

  2. Christophe Barbraud says:

    At the last meeting of the ACAP Population and Conservation Status Working Group in April 2013, several experts questioned about the values of generation time that were used in the species trend analyses used to reassess the status of these species. For example, it may be surprising to have a generation time of nearly 25 years for the white chinned petrel and only 19 years for the black footed albatross. I assume these generations time were estimated with the demographic invariant method using local estimates of adult survival and age at first breeding. However, these local rates may not be representative of the optimal generation time which is directly linked to the maximum growth rate when populations are in ideal environments (Niel & Lebreton 2005, Dillingham 2010).

    Therefore a more standardized way of calculating optimal generation time could be to use the approach developed in Dillingham and Fletcher (2011) specifically on albatrosses and petrels. They provide estimates of maximum population growth rates (their table 2) from which optimal generation times can easily be calculated.

    Dillingham, P.W. 2010. Generation time and the maximum growth rate for populations with age-specific fecundities and unknown juvenile survival. Ecological Modelling 221: 895-899.

    Dillingham, P.W. & Fletcher, D. 2011. Potential biological removal of albatrosses and petrels with minimal demographic information. Biological Conservation 144: 1885-1894.

    Niel, C. & Lebreton, J.-D. 2005. Using demographic invariants to detect overharvested bird populations from incomplete data. Conservation Biology 19: 826-835.

  3. Peter Hirst says:

    I have never seen a White-chinned Petrel, but I think I can make a comment within the following context. Where there is evidence that humanity is actively killing large numbers of a species, which apparently is the case with this bird – as by-catch in the fishing industry – then I believe it should be listed as endangered. Doing so would also help to promote the message that by-catch (which threatens numerous species allover the planet with extinction) in the fishing industry remains at unacceptable levels.

  4. Azwianewi Makhado and Robert Crawford says:

    The fact sheet for the species could be updated to include the recent population estimate for the Prince Edward Islands. P. G. Ryan • B. J. Dilley • M. G. W. Jones The distribution and abundance of white-chinned petrels (Procellaria aequinoctialis) breeding at the sub-Antarctic Prince Edward Islands. Polar Biol (2012) 35:1851–1859.

    BirdLife should have data on by-catch mortality off southern Africa, which was reported to ACAP.

  5. Andy Symes says:

    Preliminary proposals

    Based on available information, our preliminary proposal for the 2014 Red List is to pend the decision on White-chinned Petrel Procellaria aequinoctialis and keep this discussion open until early 2015, while leaving the current Red List category unchanged in the 2014 update.

    There is now a period for further comments until the final deadline of 31 March, after which recommended categorisations will be put forward to IUCN.

    The final Red List categories will be published on the BirdLife and IUCN websites in mid-2014, following further checking of information relevant to the assessments by both BirdLife and IUCN.

  6. Andy Symes says:

    Recommended categorisation to be put forward to IUCN

    Following further review, there has been no change to our preliminary proposal for the 2014 Red List status of this species.

    This discussion will remain open for further comments and information until early 2015, and the current Red List category will remain unchanged in 2014.

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