Sven Lunsche Image © Sven Lunsche

White-chinned Petrel

Procellaria aequinoctialis

Number Of Mature
Individuals (Regional)

109 600 – 166 000

Regional
Population Trend

Decreasing

vu

2025
Regional Category

Vulnerable

Search by species

CONTENTS
Loading navigation...

    Overview

    Names

    IOC English Name:

    White-chinned Petrel

    SA & IOC Scientific Name:

    Procellaria aequinoctialis

    BirdLife International Taxonomy (scientific name):

    Procellaria aequinoctialis

    Order:

    PROCELLARIIFORMES

    Family:

    Procellariidae

    Species name author:

    Linnaeus 1758

    Afrikaans:

    Bassiaan

    Sesotho (South Africa):

    Sesotho (Lesotho):

    Siswati:

    Zulu:

    umantantontshebemhlophe

    Current Assessment Status

    2025 Regional Category [Criteria]

    VU [A3e+4bcde; D2]

    2024 Global Category [Criteria]

    VU [A4bcde]

    Population size (Regional)

    33 000 – 50 000 breeding pairs (Ryan et al. 2012) (c. 109 600 – 166 000 mature individuals)

    Population size (Global)

    3 000 000 mature individuals (BirdLife International 2018)

    Distribution size (EOO) (Regional) km2

    c. 720 (breeding)

    Distribution size (EOO) (Global) km2

    173 000 000 (BirdLife International 2018)

    Distribution size (AOO) (Regional) km2

    334 (breeding)

    Generation time

    24.7 years (BirdLife International 2018)

    Status change reason

    No Change

    Migrant (in the region)

    Native and breeding and non-breeding visitor

    Regional endemic

    No

    Historic Listing Information

    2000 Regional Status

    NT [A1cde+2cde]

    2015 Regional Status

    VU [A4bcde; D2]

    Status change reason (if applicable)

    Genuine (recent)

    2015 Population size (Regional)

    40 000 (33 000 – 50 000) pairs

    2015 Global Status

    VU [A4bcde]

    Reason for Inclusion

    Reason for Inclusion in the Assessment

    The White-chinned Petrel Procellaria aequinoctialis was previously assessed regionally (Wanless and Jones 2015) and currently assessed globally (BirdLife International 2018) as Vulnerable. The accuracy of the global population estimate is unknown complicating the application of the regional population filter. A cautionary approach was adopted and the species included in the assessment.

    Category Justification

    Category Justification

    The regional population of White-chinned Petrel has been estimated at 40 000 (33 000 – 50 000) pairs (min c. 109 600, avg 132 800, max 166 000 mature individuals) that breed at Prince Edward Island and Marion Island, with no updated censusing since 2009. However, because the species is bycatch prone – an ongoing decline is suspected in both the global and regional populations. The species is classified as globally Vulnerable [A4bcde] due to suspected and predicted declines over three generations, and the regional population adopts this threat category and criteria. The regional population additionally meets the criteria for Vulnerable [D2] as it occurs at two locations and is threatened by fisheries-related mortality. The species also qualifies for Vulnerable under Criterion A3 due to projected future declines based on expert-assessed extinction horizons due principally to the threat of House Mice Mus musculus on Marion Island (Preston et al. 2019). While there is limited direct evidence of ongoing population decline currently, predictive assessments suggest that the species may experience a significant reduction over the next three generations. The extinction horizon estimates indicate that the species’ population may decline by 49% within this period, exceeding the threshold for VU under A3 (Lee 2025). The White-chinned Petrel is regionally assessed as Vulnerable [A3e+4bcde; D2]. The global population is declining, and it is expected that no substantial rescue effect will occur, and the category is left unchanged.

    Population Justification

    The global population has been quantified at c. 3 million mature individuals (BirdLife International 2018) while Ryan et al. (2012) estimated the global population of the nominate form to be c. 1.1 million pairs (c. 3 650 000 mature individuals). Compared to surface-nesting species such as albatrosses and giant petrels, the world population is poorly known (Ryan et al. 2012) and the current estimate of c. 3 million mature individuals has been cited in global assessments since 2012 (BirdLife International 2018). Within the region, a comprehensive assessment of the breeding sub-population at the Prince Edward Islands estimated to number 21 800 – 26 000 pairs at Marion and 9000 – 15 000 pairs at Prince Edward, giving an estimate of 40 000 (33 000 – 50 000) pairs in the region (Ryan et al. 2012). The confidence in this estimate is moderate to low, but these remain the most recently published data.

    Trend Justification

    While global population data is lacking, for most colonies the global population is projected to decline by >50% over three generations (Birdlife International 2018). The projection is based on burrow occupancy declines of 28% on Bird Island, South Georgia. Population monitoring on Marion Island between 1996-1997 and 1999-2000 recorded a 14.1% per year decrease in the population (Nel et al. 2002a) while data from at-sea surveys suggest a 35% decline in the southern Indian Ocean during 1981-2007 (Péron et al. 2010). Data from the Crozet Archipelago show a decline of 37% in breeding pairs between 1983-2004 (Barbraud et al. 2008). Data from fisheries impacts and population models also suggest a decline in numbers on Kerguelen Island (Barbraud et al. 2009). No population trends are available from the New Zealand or South African island colonies. However, even if these were to be considered stable, the estimated annual decline of 1.9% on South Georgia Island (Martin et al. 2009) and suspected population declines on Kerguelen Island could indicate that the rate of overall decline is higher. Updated assessments are needed at the larger colonies to fully assess the overall trend. The true rate of decline of the regional population is unknown, as a census has not been conducted since 2009.

    Future population projections based on extinction horizon estimates suggest that significant reductions on the Prince Edward Islands may occur within the next three generations (Preston et al. 2019). While no significant recent declines have been observed, the potential for future declines justifies careful consideration under Criterion A3 (Lee 2025). Ongoing monitoring is essential to validate these projections and determine whether the species is experiencing measurable population decreases.

    Biology & Ecology

    Taxonomy

    The White-chinned Petrel Procellaria aequinoctialis comprises two sub-species level taxa namely P. a. steadi breeding on New Zealand islands and the nominate form P. a. aequinoctialis breeding on all other Atlantic and Indian Ocean islands (Rexer-Hubert et al. 2019). Only the nominate form has been recorded foraging off southern Africa. Tracking, genetic and stable isotope data all suggest that the waters off southern Africa primarily host birds from the south-western Indian Ocean colonies; Prince Edward Islands, Crozet Islands and Kerguelen Island (Weimerskirch et al. 1999, Rexer-Huber 2017, Rollinson et al. 2018).

    Identification

    50–58 cm, 1.2–1.4 kg. Sexes alike in plumage but differ in size and bill depth. A relatively large petrel with all-dark plumage except for variable amount of white on chin. Occasional variants have white spots on the head, sides of the face, belly or wings. Bill grey-white in juvenile, becoming ivory in older birds. Flight feathers are shinier and, in contrast to the coverts, can appear silvery. Eye dark brown. Legs and feet blackish grey, often with paler bases to webs. Confusion with Spectacled Petrel is possible, but the diagnostic features for the latter are its white forehead, usually complete circles around the eyes and a dark maxillary unguis (Ryan 2005).

    Distribution

    The species has a wide distribution across all of the Southern Ocean (Croxall et al. 1984), occurring from the pack-ice of Antarctica northwards to 20˚S (Weimerskirch et al. 1999). It breeds on eight islands, the French, New Zealand and South African Subantarctic islands, as well as on South Georgia (Islas Georgias del Sur) and the Falklands (Islas Malvinas) (BirdLife International 2018). Within the region, it breeds on two islands namely Marion (290 km2) and Prince Edward (44 km2). Breeding and overwintering birds foraging off the coast of South Africa represent sub-populations from the Crozet, Kerguelen and the Prince Edward Islands, with foraging ranges extending along the Benguela and Agulhas currents, south of 25° degrees South (Rexer-Huber 2017). These waters are the main wintering area for birds from these islands, which together represent a significant proportion of the global population (Barquete 2012).

    Ecology

    The White-chinned Petrel is a colonial nesting species that breeds on an annual basis with the breeding season extending from October to May (Jouventin et al. 1985). It forages day and night, feeding mainly by surface-seizing, but is also capable of diving to depths of approximately 16 m (Rollinson et al. 2014). The diet in South African continental waters comprises mainly of offal from trawlers, small fish, mantis shrimps Squilla armata, cuttlefish Sepia spp. and other cephalopods (Jackson 1988). The species is attracted to fishing activity (Banda et al. 2024). A generation length of 24.7 years was calculated based on a published estimate of mean age at first breeding and a published estimate of mean annual survival (BirdLife International 2018).

    Threats & Conservation

    Threats

    The main threat faced by this species is the high rate of incidental mortality in fisheries where it is the most commonly caught species in the Southern Ocean on both longline and demersal trawl gear (Nel et al. 2002b, Barbraud et al. 2009, Ryan et al. 2012, Maree et al. 2014, Rollinson et al. 2017, Da Rocha et al. 2021). White-chinned Petrels are attracted to both discards and baited hooks which combined with their ability to dive and their ability to forage by day and night, makes them highly vulnerable to accidental mortality by fisheries (Rollinson et al. 2018). An estimated 45 000 per year were killed by longlines in the Southern Ocean Patagonian toothfish fishery, while 8000 per year were caught off South Africa during the early 1990s at the start of the longline hake fisheries (Barnes et al. 1997). Bycatch in this fishery has decreased substantially since then (Petersen et al. 2009). It is the seabird killed most frequently by the pelagic longline fishery, targeting tuna spp. and Swordfish Xiphias gladius off South Africa, comprising around 66% of bycatch birds each year (Rollinson et al. 2017). Prior to the mid-2000s, demersal trawl fisheries killed large numbers of seabirds, including White-chinned Petrels, off South Africa (Watkins et al. 2008). The introduction of mitigation measures from the mid-2000s greatly reduced these numbers (Maree et al. 2014). However, White-chinned Petrel mortality may be higher than recorded, considering their recorded attraction to fishing activity in the region (Banda et al. 2024). The species’ nocturnal habits and low observer coverage, across South African fisheries, may result in the under-recording of this species’ bycatch (Maree et al. 2014).

    The introduced and invasive House Mouse on Marion Island is known to predate on burrowing petrel species including Grey and Great-winged Petrels with indirect evidence for White-chinned Petrels (Dilley et al. 2018).

    Conservation Measures Underway

    BirdLife South Africa’s Albatross Task Force is actively researching new technologies to reduce incidental mortality in fisheries, as well as monitoring observer data and estimating annual bycatch in selected fisheries. It promotes the development and enforcement of best-practice to reduce incidental mortality as well as supporting the construction and distribution of devices such as bird-scaring lines for fishing vessels. BirdLife International is actively lobbying Regional Fisheries Management Organisations, particularly the Indian Ocean Tuna Commission, to improve the conservation measures required of longline fishing vessels. It is also supporting moves to create regional observer programmes and strengthen observer data collection and reporting procedures. The Mouse Free Marion project partnership between the Department of Forestry, Fisheries and the Environment and BirdLife South Africa is working towards the eradication of house mice on Marion Island. The project aims to protect 19 of the 28 breeding seabird species considered at risk from mice predation on the island. The species is protected under the Sea Birds and Seals Protection Act, 1973 (Act No. 46 of 1973), Marine Living Resources Act (Act No. 18 of 1998): Publication of Policy on the Management of Seals, Seabirds and Shorebirds: 2007 and the South African National Plan of Action for Reducing the Incidental Catch of Seabirds in Longline Fisheries (SANPOA 2008). The Prince Edward Islands are listed as a Ramsar Wetland of International Importance, and as a Special Nature Reserve under the Environment Conservation Act (No 73 of 1989) and the Prince Edward Islands Management Plan 1996. The Prince Edward Islands Marine Protected Area was proclaimed in 2013.

    Conservation Measures Proposed

    • Ongoing measures by BirdLife South Africa and BirdLife International, to improve seabird bycatch management measures by fisheries to reduce incidental mortality of seabirds, should be supported and extended to distant water fishing nations operating in the Southern Ocean.
    • The South African Government should promote international best-practice for reducing seabird mortalities at fora such as the Indian Ocean Tuna Commission and the Commission for the Conservation of Southern Bluefin Tuna.
    • Regional and national observer programmes and reporting of their data remain of paramount importance in understanding the scale of incidental mortality and potential effectiveness of (and level of compliance with) mitigation measures employed. Programmes to repeat the breeding censuses of Indian Ocean populations that forage along South Africa’s coastline and tracking birds to assess the degree of overlap with various fisheries, remain important tools for assessing and addressing the ongoing threats from fishery interactions.
    • Supporting ongoing conservation efforts by BirdLife South Africa and relevant government departments towards the removal of house mice from Marion Island, one of the foremost breeding grounds for globally threatened seabird species, is of global importance and a key conservation priority for South Africa.
    • Review and update the National Plan of Action for Seabirds to implement management measures and target actions that address seabird bycatch information gaps, uptake of management measures and effective compliance and monitoring tools for all fisheries that pose a risk to seabirds.

    Research Priorities and Questions

    • Updated regional population estimates are required.
    • The risk of the regional sub-population to various fisheries requires more attention. Current albeit limited tracking studies (Banda et al. 2024, Rexer-Huber 2017, Rollinson et al. 2018, Weimerskirch et al. 1999) indicate appreciable numbers migrate to South African continental waters during breeding and non-breeding periods and are vulnerable to fishing activities there. The dispersal patterns, proportional to the population, by sex, age-class and year, and therefore the risks posed to them at each stratum by different fisheries, needs to be quantified.
    • Meta-population dynamics between birds breeding on the Prince Edward Islands and those from the relatively nearby French Southern Ocean territories (Crozet and Kerguelen Archipelagos) would help with understanding patterns and relative risks from various fisheries.

    Contributors & References

    Assessor/s

    Andrea Angel

    Reviewer/s

    Shamiso Banda, Dominic Rollinson

    References

    Banda S, Pistorius P, Collet J, Corbeau A, Weimerskirch H, Pajot A, Keys DZ, Orgeret F. 2024. Gauging the threat: exposure and attraction of sooty albatrosses and white-chinned petrels to fisheries activities in the southern Indian ocean. ICES Journal of Marine Science 81: 75–85.

    Barbraud C, Marteau C, Ridoux V, Delord K, Weimerskirch H. 2008. Demographic response of a population of white‐chinned petrels Procellaria aequinoctialis to climate and longline fishery bycatch. Journal of Applied Ecology 45(5): 1460–1467.

    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.

    Barnes KN, Ryan PG, Boix-Hinzen C. 1997. The impact of the hake Merluccius spp. longline fishery off South Africa on procellariiform seabirds. Biological Conservation 82(2): 227–234.

    Barquete V. 2012. Using stable isotopes as a tool to understand the trophic relationships and movement of seabirds off Southern Africa. Doctoral dissertation, University of Cape Town

    BirdLife International. 2018. Procellaria aequinoctialis. The IUCN Red List of Threatened Species 2018: e.T22698140A132628887. https://dx.doi.org/10.2305/IUCN.UK.2018-2.RLTS.T22698140A132628887.en. [Accessed on 10 March 2025].

    Croxall JP, Prince PA, Hunter I, McInnes SJ, Copestake PG. 1984. Seabirds of the Antarctic Peninsula, islands of the Scotia Sea, and Antarctic continent between 80°W and 20°W: their status and conservation. In: Croxall JP, Evans PGH, Schreiber RW (eds), Status and conservation of the world’s seabirds. Cambridge, United Kingdom: International Council for Bird Preservation. pp 637–666.

    Da Rocha N, Oppel S, Prince S, Matjila S, Shaanika TM, Naomab C, Yates O, Paterson JR, Shimooshili K, Frans E, Kashava S. 2021. Reduction in seabird mortality in Namibian fisheries following the introduction of bycatch regulation. Biological Conservation 253: 108915.

    Dilley BJ, Schoombie S, Stevens K, Davies D, Perold V, Osborne A, Schoombie J, Brink CW, Carpenter-Kling T, Ryan PG. 2018. Mouse predation affects breeding success of burrow-nesting petrels at sub-Antarctic Marion Island. Antarctic Science 30(2): 93–104.

    Jackson S. 1988. Diets of the white-chinned petrel and sooty shearwater in the southern Benguela region, South Africa. Condor 90: 20–28.

    Jouventin P, Mougin JL, Stahl JC, Weimerskirch H. 1985. Comparative biology of the burrowing petrels of the Crozet Islands. Notornis 32(3): 157–220.

    Lee ATK. 2025. The application of IUCN Regional Red List Criteria to the species of South Africa’s Prince Edward Islands. Unpublished report. Johannesburg: BirdLife South Africa.

    Maree BA, Wanless RM, Fairweather TP, Sullivan BJ, Yates O. 2014. Significant reductions in mortality of threatened seabirds in a South African trawl fishery. Animal Conservation 17(6): 520–529.

    Martin AR, Poncet S, Barbraud C, Foster E, Fretwell P, Rothery P. 2009. The white-chinned petrel (Procellaria aequinoctialis) on South Georgia: population size, distribution and global significance. Polar Biology 32: 655–661.

    SANPOA. 2008. South Africa National Plan of Action for Reducing the Incidental Catch of seabirds in Longline Fisheries. Department of Environmental Affairs and Tourism.

    Nel DC, Ryan PG, Crawford RJ, Cooper J, Huyser OA. 2002a. Population trends of albatrosses and petrels at sub-Antarctic Marion Island. Polar Biology 25: 81–89.

    Nel DC, Ryan PG, Watkins BP. 2002b. Seabird mortality in the Patagonian toothfish longline fishery around the Prince Edward Islands, 1996–2000. Antarctic Science 14(2): 151–161.

    Péron C, Delord K, Phillips RA, Charbonnier Y, Marteau C, Louzao M, Weimerskirch H. 2010. Seasonal variation in oceanographic habitat and behaviour of white-chinned petrels Procellaria aequinoctialis from Kerguelen Island. Marine Ecology Progress Series 416: 267–284.

    Petersen SL, Honig MB, Ryan PG, Underhill LG. 2009. Seabird bycatch in the pelagic longline fishery off southern Africa. African Journal of Marine Science 31(2): 191–204.

    Preston GR, Dilley BJ, Cooper J, Beaumont J, Chauke LF, Chown, SL, Devanunthan N, Dopolo M, Fikizolo L, Heine J, Henderson S, Jacobs CA, Johnson F, Kelly J, Makhado AB, Marais C, Maroga J, Mayekiso M, McClelland G, Mphepya J, Muir D, Ngcaba N, Ngcobo N, Parkes JB, Paulsen F, Schoombie S, Springer K, Stringer C, Valentine H, Wanless RM, Ryan PG. 2019. South Africa works towards eradicating introduced house mice form the sub-Antarctic Marion Island: the largest island yet attempted for mice. In: Veitch CR, Clout MN, Martin AR, Russell JC, West CJ (eds), Island Invasives: Scaling up to Meet the Challenge. Occasional Paper of the IUCN Species Survival Commission; Vol. 62 pp 40–46. IUCN. https://portals.iucn.org/library/node/48358.

    Rexer-Huber K. 2017. White-chinned petrel distribution, abundance and connectivity have circumpolar conservation implications. Doctoral dissertation, University of Otago.

    Rexer‐Huber K, Veale AJ, Catry P, Cherel Y, Dutoit L, Foster Y, McEwan JC, Parker GC, Phillips RA, Ryan PG, Stanworth AJ. 2019. Genomics detects population structure within and between ocean basins in a circumpolar seabird: the white‐chinned petrel. Molecular Ecology 28(20): 4552–4572.

    Rollinson DP, Dilley BJ, Ryan, PG. 2014. Diving behaviour of white-chinned petrels and its relevance for mitigating longline bycatch. Polar Biology 37: 1301–1308.

    Rollinson DP, Wanless RM, Ryan PG. 2017. Patterns and trends in seabird bycatch in the pelagic longline fishery off South Africa. African Journal of Marine Science 39(1): 9–25.

    Rollinson DP, Dilley BJ, Davies D, Ryan PG. 2018. Year-round movements of white-chinned petrels from Marion Island, south-western Indian Ocean. Antarctic Science 30(3): 183– 195.

    Ryan PG. 2005. White-chinned Petrel Procellaria aequinoctialis. In: Hockey PAR, Dean WRJ, Ryan PG (eds), Roberts – Birds of Southern Africa, 7th Edn. Cape Town, South Africa: The Trustees of the John Voelcker Bird Book Fund. pp 668.

    Ryan PG, Dilley BJ, Jones MGW. 2012. The distribution and abundance of white-chinned petrels (Procellaria aequinoctialis) breeding at the sub-Antarctic Prince Edward Islands. Polar Biology 35: 1851–1859.

    Wanless RM, Jones MGW. 2015. White-chinned Petrel Procellaria aequinoctia. In: Taylor MR, Peacock F, Wanless RW (eds), The Eskom Red Data Book of Birds of South Africa, Lesotho and Swaziland. Johannesburg, South Africa: BirdLife South Africa. pp 255–257.

    Watkins BP, Petersen SL, Ryan PG. 2008. Interactions between seabirds and deep‐water hake trawl gear: an assessment of impacts in South African waters. Animal Conservation 11(4): 247–254.

    Weimerskirch H, Catard A, Prince PA, Cherel Y, Croxall JP. 1999. Foraging white-chinned petrels Procellaria aequinoctialis at risk: from the tropics to Antarctica. Biological Conservation 87(2): 273–275.

    Citation

    Angel A 2025. White-chinned Petrel. In: Lee ATK, Rose S, Banda S, Bezeng SB, Maphalala MI, Maphisa DH, Smit-Robinson H (eds), The 2025 Red Data Book of Birds of South Africa, Lesotho and Eswatini. Johannesburg, South Africa: BirdLife South Africa. Available at: https://www.birdlife.org.za/red-list/white-chinned-petrel/

    Our generous sponsors

    Sponsor logoSponsor logoSponsor logoSponsor logoSponsor logoSponsor logoSponsor logoSponsor logo