Thalassarche bulleri 


Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Aves Procellariiformes Diomedeidae

Scientific Name: Thalassarche bulleri
Species Authority: (Rothschild, 1893)
Common Name(s):
English Buller's Albatross, Buller's Mollymawk
Diomedea bulleri bulleri Sibley and Monroe (1990, 1993)
Diomedea bulleri bulleri Turbott (1990)
Diomedea bulleri bulleri Collar et al. (1994)
Diomedea bulleri bulleri Christidis and Boles (1994)
Diomedea bulleri bulleri Stotz et al. (1996)
Taxonomic Source(s): del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A. and Fishpool, L.D.C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Lynx Edicions BirdLife International.
Taxonomic Notes: Diomedea bulleri (Sibley and Monroe 1990, 1993) is retained as a species in the genus Thalassarche following Brooke (2004) contra Robertson and Nunn (1998) who split it into T. bulleri and T. platei.

Identification information: 79 cm. Small, grey-headed, white-and-black albatross. Adult, silvery-grey forehead. Grey head, throat. Black around and in front of eye. White crescent behind and below eye. Dark grey back, upperwing, tail. White rump, underparts. White underwing with black tip, broad, sharply-demarcated band at leading edge. Large black bill, yellow on upper, lower ridges, tip. Juvenile, darker brownish-grey head, brownish bill. Similar spp. Grey-headed Albatross T. chrysostoma has broader, less distinct black leading margin to underwing. Salvin's Albatross T. salvini is larger with different underwing pattern.

Assessment Information [top]

Red List Category & Criteria: Near Threatened ver 3.1
Year Published: 2012
Date Assessed: 2012-05-01
Assessor(s): BirdLife International
Reviewer(s): Butchart, S. & Symes, A.
Contributor(s): Taylor, G.A., Stahl, J.-C., Molloy, J., Waugh, S., Robertson, H., Walker, K. & McClellan, R.
Facilitator/Compiler(s): Stattersfield, A., Calvert, R., McClellan, R., Mahood, S., Nel, D.
This species has been listed as Near Threatened because, although it is restricted to a tiny small area when breeding, the population is stable and the islands on which it breeds are moderately widely spread so it is unlikely to become highly threatened in a short time owing to human activities or stochastic events.

Previously published Red List assessments:
2010 Near Threatened (NT)
2008 Near Threatened (NT)
2005 Vulnerable (VU)
2004 Vulnerable (VU)
2003 Vulnerable (VU)
2000 Vulnerable (VU)
1994 Lower Risk/near threatened (LR/nt)
1988 Lower Risk/least concern (LR/lc)

Geographic Range [top]

Range Description: Thalassarche bulleri is endemic to New Zealand. There are colonies on the Snares (8,713 pairs) and Solander (4,912) Islands in the south (Sagar et al. 1999b, Sagar and Stahl 2005), Forty-Fours (c.14,500) and Big and Little Sister (2,150) Islands in the Chatham Island group (ACAP 2009), and Rosemary Rock, Three Kings Islands (20 pairs) off North Island (Croxall and Gales 1998). This totals approximately 30,500 breeding pairs. The Snares Islands population has almost doubled since 1969, but the rate of increase has slowed in the 1990s (Sagar et al. 1999b, Sagar and Stahl 2005). The Solander Islands population appears to have remained relatively stable during 1985-1996, and has increased by around 18% during 1996-2002 (Sagar and Stahl 2005). The Chatham Island population is thought to be stable (ACAP 2009). Juveniles and non-breeding adults can disperse across the south Pacific Ocean to the west coast of South America (Stahl and Sagar 2000b, Taylor 2000, Spear et al. 2003).

Countries occurrence:
Australia; Chile; New Zealand; Peru
Antarctica; Falkland Islands (Malvinas); South Africa
Present - origin uncertain:
Estimated area of occupancy (AOO) - km2: 4
Continuing decline in area of occupancy (AOO): Unknown
Extreme fluctuations in area of occupancy (AOO): No
Estimated extent of occurrence (EOO) - km2: 4
Continuing decline in extent of occurrence (EOO): Unknown
Extreme fluctuations in extent of occurrence (EOO): No
Number of Locations: 4
Continuing decline in number of locations: Unknown
Extreme fluctuations in the number of locations: No
Upper elevation limit (metres): 50
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: The estimated annual breeding population is 31,939 pairs, made up of 8,877 pairs on the Snares Islands, 4,912 pairs on the Solander Islands, 16,000 pairs on the Forty-Fours, 2,130 pairs on Big and Little Sister Islands in the Chatham Island group, and 20 pairs on Rosemary Rock, Three Kings Islands off North Island.

Trend Justification:  The Snares Islands population has almost doubled since 1969, but the rate of increase has slowed in the 1990s (Sagar et al. 1999b; Sagar and Stahl 2005). The Solander Islands population appears to have remained relatively stable during 1985-1996, and increased by around 18% during 1996-2002 (Sagar and Stahl 2005). Overall, the population is considered stable.

Current Population Trend: Stable
Additional data:
Continuing decline of mature individuals: Unknown
Extreme fluctuations: No Population severely fragmented: No
No. of subpopulations: 3 Continuing decline in subpopulations: Unknown
Extreme fluctuations in subpopulations: No All individuals in one subpopulation: No

Habitat and Ecology [top]

Habitat and Ecology: Behaviour Breeding is annual and colonial. On the Snares Islands most eggs are laid in January, hatch March to April and chicks fledge in August to September. Birds begin to return to colonies at least three years after fledging, and the average age of first breeding is 10-11 years. On the Chatham Islands, eggs are laid in October to November, hatch in January and the chicks fledge in June to July (ACAP 2009). On Little Sister, annual productivity 1994-1996 was 57-60%, and mean annual adult survival 1974-1995 was 93.5% (Croxall and Gales 1998). On the Snares, annual productivity 1995-98 was 70.8% (Sagar et al. 2002), and mean annual adult survival increased from 92.0% in 1983-85 to 95.5% in 1992-97 (Sagar et al. 2000). Breeding and non-breeding adults forage between 40 and 50°S from Tasmania eastwards to the Chatham Rise (Stahl et al. 1998, Stahl and Sagar 2000a, b, BirdLife International 2004, Sagar and Stahl 2005). Females from the Snares Islands tend to conduct longer, more distant foraging trips during pre-egg and brood guard periods of the breeding cycle, than males (BirdLife International 2004). Birds usually forage individually but large numbers may gather to feed at concentrated food sources such as swarms of crustaceans, occasionally making surface plunges or shallow dives (ACAP 2009). Satellite tracking studies from the Snares and Solander Islands show that the distribution of the breeding birds varies with the stage of the breeding cycle. During incubation (Jan-Mar) birds range along the shelf slope off the east and west coasts of the South Island, New Zealand, and into the Tasman Sea; during the guard stage (Mar-Apr) birds are usually found along the shelf slope and shelf areas east and west of the southern New Zealand, and during the post-guard stage (May-Aug) birds occur along the shelf slopes of both coasts of the South Island. After breeding, birds of all ages (including fledglings) migrate to slopes off Chile and Peru (ACAP 2009). Habitat Breeding It breeds in a variety of habitats including grassy meadows, tussock-covered slopes and cliffs, scrub and under forest canopy (Marchant and Higgins 1990). Diet It feeds mostly on fish, squid and tunicates, also octopuses and crustacea (West and Imber 1986, James and Stahl 2000).

Systems: Terrestrial; Marine
Continuing decline in area, extent and/or quality of habitat: Unknown
Generation Length (years): 16.5
Movement patterns: Full Migrant
Congregatory: Congregatory (and dispersive)

Threats [top]

Major Threat(s): A severe storm in 1985 almost completely removed soil and vegetation from the Sisters and Forty-Fours Islands. Although T. bulleri seems unaffected, further habitat degradation could result in population decreases, as has been predicted for Northern Royal Albatross Diomedea sanfordi (Croxall and Gales 1998). It is one of the more common bycatch species in the longline tuna fishery in New Zealand waters, where all birds caught are adults (Murray et al. 1993, Bartle 1999). It is also caught by squid trawlers in low numbers despite the banning of net-sonde cables in 1992 (Taylor 2000). Recent data from Chile shows that T. bulleri is one of several species caught in the pelagic longline swordfish fishery (ACAP 2009). Weka Gallirallus australis was introduced to Big Solander and may take eggs and chicks (Taylor 2000).

Conservation Actions [top]

Conservation Actions: Conservation Actions Underway
CMS Appendix II and ACAP Annex 1. Long-term studies have been initiated in all main populations (Taylor 2000). Most islands are legally protected, but all Chatham colonies are on private land.

Conservation Actions Proposed
Complete an accurate census on Forty-Fours and Big Sister. Census all colonies for 2-4 consecutive years every 10 years, and Little Sister at least every five years. Develop and effectively implement mitigation devices/techniques to minimise fisheries bycatch. Establish observer coverage on fisheries east of the North Island and the Chathams. Eradicate G. australis from Big Solander Island. Obtain legal protection for Forty-Fours and Sisters Islands, and continued access for research (Taylor 2000).

Citation: BirdLife International. 2012. Thalassarche bulleri. The IUCN Red List of Threatened Species 2012: e.T22728328A40183943. . Downloaded on 02 December 2015.
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