Sooty Shearwater
Ardenna grisea
Number Of Mature
Individuals (Regional)
Unknown
Regional
Population Trend
Decreasing
2025
Regional Category
Near Threatened
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CONTENTSOverview
Names
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IOC English Name: |
Sooty Shearwater |
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SA & IOC Scientific Name: |
Ardenna grisea |
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BirdLife International Taxonomy (scientific name): |
Ardenna grisea |
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Order: |
PROCELLARIIFORMES |
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Family: |
Procellariidae |
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Species name author: |
Gmelin 1789 |
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Afrikaans: |
Malbaartjie |
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Sesotho (South Africa): |
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Sesotho (Lesotho): |
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Siswati: |
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Zulu: |
isikamanzelinsundu |
Current Assessment Status
|
2025 Regional Category [Criteria] |
NT [A2de+3de+4de] |
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2024 Global Category [Criteria] |
NT [A2de+3de+4de] (BirdLife International 2019) |
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Population size (Regional) |
Unknown |
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Population size (Global) |
8 800 000 mature individuals (BirdLife International 2019) |
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Distribution size (EOO) (Regional) km2 |
Unknown |
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Distribution size (EOO) (Global) km2 |
47 700 000 (breeding/resident) |
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Distribution size (AOO) (Regional) km2 |
Unknown |
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Generation time |
21 years (BirdLife International 2019) |
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Status change reason |
No Change |
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Migrant (in the region) |
Yes (non-breeding visitor) |
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Regional endemic |
No |
Historic Listing Information
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2000 Regional Status |
LC |
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2015 Regional Status |
NT [A2de+3de+4de] |
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Status change reason (if applicable) |
Genuine (recent) |
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2015 Population size |
20 000 000 mature individuals (global) |
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2015 Global Status |
NT [A2de+3de+4de] |
Reason for Inclusion
Reason for Inclusion in the Assessment
The species is currently listed as globally Near Threatened and occurs in large numbers in South African waters as a non-breeding visitor. It was listed as regionally Least Concern in 2000, and uplisted to regionally Near Threatened in 2015.
Category Justification
Category Justification
The Sooty Shearwater Ardenna griseus is listed as globally Near Threatened due to suspected rapid population declines under Criteria A2de+3de+4de. The global population is approaching a 30% reduction over three generations caused by fisheries-related mortality, the exploitation of chicks, impacts of introduced taxa, and climate-related habitat loss. The global status of this species is adopted as the regional status, as it is a non-breeding visitor here.
Population Justification
According to the 2019 global assessment (BirdLife International 2019), the global population is estimated at 4.4 million pairs, which is approximately 19 – 23.6 million individuals (Newman et al. 2009, Waugh et al. 2013). Within the region, the visiting population which occurs over the continental shelf and shelf-break was crudely estimated at c. 750 000 birds in winter and 320 000 birds in summer (Crawford et al. 1991). Confidence in the regional population estimate is low and confidence in the global estimate is medium.
Trend Justification
The global population is suspected to be in decline (Brooke 2004, BirdLife International 2019). Decreases have been reported at colonies in their core breeding range and wintering areas (Butcher and Niven 2007, Clucas et al. 2008, Scott et al. 2008, Moller et al. 2009, Waugh et al. 2013), but an increase in the Falkland Islands population was recently estimated (Clark et al. 2019). The reduction in population size is suspected to be moderately rapid although the rate of decline has not been calculated (BirdLife International 2019). Confidence in this trend estimate is low.
Biology & Ecology
Taxonomy
The species was previously classified in the genus Puffinus as P. griseus (BirdLife International 2019). Easily the most common member of the genus Ardenna (Carboneras et al. 2024).
Identification
40–45 cm, 600 g. Both sexes are similar, and juveniles resemble adults. The upper parts are blackish-brown with slightly paler tips. This large dark shearwater has relatively narrow, pointed wings and pale areas on the central underwing. Most of its plumage is uniformly sooty-brown to dark grey, usually darkest on the head and the upper surface of the primaries and tail. The dorsal area may have a scaly pattern, especially on the scapulars. The chin and upper throat are slightly paler, while the rest of the underparts from the upper chest are similar in color to the upperparts but slightly lighter. The axillaries are dark, and the underwing coverts are paler brownish or grey, with varying amounts of white on the innermost greater coverts, median, and lesser coverts. The iris is blackish-brown, and the bill is brownish-grey to dark grey, sometimes blacker at the tip. The legs and feet are pale flesh, dull pink-flesh, or greyish. Juveniles are similar to adults but have fresh plumage from May to July, while most older birds are in wing moult (Carboneras et al. 2024). Confusing species in the region include Flesh-footed Shearwater A. carneipes and larger White-chinned Petrel Procellaria aequinoctialis (Ryan 2005).
Distribution
The Sooty Shearwater is a common shearwater breeding on islands off New Zealand, Australia, Chile, and the Falkland Islands (Malvinas). In Australia, colonies are found on 17 islands, all with fewer than 1000 pairs. Southern Chile hosts colonies up to 200 000 pairs, with the largest colony on Isla Guafo housing up to 4 000 000 individuals (Reyes-Arriagada et al. 2007). The Falklands (Malvinas) have 10000 – 20 000 pairs, and New Zealand supports over 180 colonies (Newman et al. 2009, Waugh et al. 2013). During the non-breeding season, the species is found throughout the Pacific and Atlantic Oceans, and Southern Ocean to at least 65 °S. The species is found throughout South African waters, primarily along the west and south coasts, but is uncommon off KwaZulu-Natal.
Ecology
This species is found singly in oceanic waters but mostly in larger flocks over the continental shelf (Ryan 2005). It nests on islands and headlands in large colonies, creating burrows for breeding under tussock grass and low scrub. Typically, birds do not return to their natal colonies until they are four years of age (Weimerskirch 1998), with the age of first breeding around 5–7 years. They feed on fish, crustaceans, and cephalopods, which they catch while diving, but also scavenge trawler discards and cetacean faeces (Evans 1982, Ryan and Moloney 1988). Aggregations of up to 10 000 birds can be seen during the winter months off the south and west coasts of Southern Africa (PG Ryan pers obs).
Threats & Conservation
Threats
Habitat change linked to climate change is a suspected reason for local decreases, although competition with the small pelagic fishery might also have played a role as this species feeds on surface schooling fish and crustaceans (PG Ryan, pers comm).
Birds have been recorded attending hake longline vessels off South Africa (Barnes et al. 1997), rendering them vulnerable to being bycaught, but there is no evidence of any birds being killed on a longline fishery.
Conservation Measures Underway
The species is protected within the region by the Sea Birds and Seals Protection Act (Act No. 46 of 1973), the Marine Living Resources Act (Act No. 18 of 1998), the Publication of Policy on the Management of Seals, Seabirds and Shorebirds: 2007, and the National Plan of Action (NPOA) for Reducing the Incidental Catch of Seabirds in Longline Fisheries 2008. Additionally, South Africa is one of the eight countries within which Albatross Task Force teams are working to reduce fisheries bycatch.
Conservation Measures Proposed
The Sooty Shearwater’s conservation efforts revolve around the application of suitable bycatch mitigation measures, monitoring of results, and ensuring that there is ongoing education, training, and publicity regarding fisheries-related mortalities – similarly to other seabirds threatened by unmitigated commercial fishing activity.
Research Priorities and Questions
- To determine the size of the visiting population.
- To document the bycatch occurring in South African waters in order to monitor its impact on the population.
Contributors & References
Assessor/s
Shamiso Banda, Hanneline Smit-Robinson
Reviewer/s
Peter Ryan
References
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: 227-234.
BirdLife International. 2019. Ardenna grisea. The IUCN Red List of Threatened Species 2019: e.T22698209A154440143. Available: https://dx.doi.org/10.2305/IUCN.UK.2019-3.RLTS.T22698209A154440143.en. [Accessed 18 July 2023].
Brooke M. 2004. Albatrosses and Petrels Across the World (Bird Families of the World). Oxford: Oxford University Press.
Butcher GS, Niven DK. 2007. Combining data from the Christmas bird count and the breeding bird survey to determine the continental status and trends of North American birds. National Audubon Society.
Carboneras C, Jutglar F, Kirwan GM. 2024. Sooty Shearwater (Ardenna grisea), version 1.1. In: del Hoyo J, Elliott A, Sargatal J, Christie DA, de Juana E, Medrano F (eds), Birds of the World. Ithaca, NY, USA: Cornell Lab of Ornithology. https://doi.org/10.2173/bow.sooshe.01.1
Clark TJ, Matthiopoulos J, Bonnet-Lebrun A, Campioni L, Catry P, Marengo I, Poncet S, Wakefield E. 2019. Integrating habitat and partial survey data to estimate the regional population of a globally declining seabird species, the sooty shearwater. Global Ecology and Conservation 17: e00554.
Clucas RJ, Fletcher DJ, Moller H. 2008. Estimates of adult survival rate for three colonies of Sooty Shearwater (Puffinus griseus) in New Zealand. Emu 108: 237–250.
Crawford RJM, Ryan PG, Williams A. 1991. Seabird consumption and production in the Benguela and western Agulhas ecosystems. South African Journal of Marine Science 11: 357–375.
Evans PGH.1982. Associations between seabirds and cetaceans. A review. Mammal Review 12(4): 187–206.
Moller H, Flecther D, Johnson PN, Bell BD, Flack D, Bragg C, Scott D, Newman J, McKechnie S, Lyver PO. 2009. Changes in sooty shearwater (Puffinus griseus) abundance and harvesting on the Rakiura Titi Islands. New Zealand Journal of Zoology 36: 325–341.
Newman J, Scott D, Bragg C, McKechnie S, Moller H, Fletcher D. 2009. Estimating regional population size and annual harvest intensity of the sooty shearwater in New Zealand. New Zealand Journal of Zoology 36: 307–323.
Reyes-Arriagada R, Campos-Ellwanger P, Schlatter RP, Baduini C. 2007. Sooty Shearwater (Puffinus griseus) on Guafo Island: the largest seabird colony in the world? Biodiversity and Conservation 16(4): 913–930.
Ryan PG. 2005. Sooty Shearwater. In: Hockey PAR, Dean WRJ, Ryan PG (eds), Roberts Birds of Southern Africa 7th Edn. Cape Town: Trustees of the John Voelcker Bird Book Fund. pp 673–674.
Ryan PG, Moloney CL. 1988. Effect of trawling on bird and seal distributions in the southern Benguela region. Marine Ecology Progress Series 45: 1–11.
Scott D, Scofield P, Hunter C, Fletcher D. 2008. Decline of sooty shearwaters, Puffinus griseus, on The Snares, New Zealand. Papers and Proceedings of the Royal Society of Tasmania 142: 185–196.
Waugh SM, Tennyson A, Taylor G, Wilson KJ. 2013. Population sizes of shearwaters (Puffinus spp.) breeding in New Zealand, with recommendations for monitoring. Tuhinga 24: 159–204.
Weimerskirch H. 1998. How can a pelagic seabird provision its chick when relying on a distant food resource? Cyclic attendance at the colony, foraging decision and body condition in Sooty Shearwaters. Journal of Animal Ecology 67: 99–109.
Citation
Banda S, Smit–Robinson H 2025. Sooty Shearwater. 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/sooty-shearwater/
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