Gray-headed Albatross Thalassarche chrysostoma Scientific name definitions

The Grey-headed Albatross is a member of the “mollymawk” group of southern ocean albatrosses. Containing five species, the mollymawks are distinctive as a group with dark wings and back, white underparts, and rump, but separable from each other by  distinctive combinations of plumage (especially of the head) and bill color. The adult Grey-headed Albatross is identified by the combination of a gray head and an orange-tipped black bill, with yellow along the ridge of the mandible and maxilla. If seen well, the adult is distinctive, but due to its delayed maturation, juvenile and sub-adult plumages are less distinctive and birds in these plumages may be confused with other mollymawks. The Gray-headed Albatross breeds on widely scattered islands in the southern oceans. It breeds in South America on the Diego Ramirez Islands, off Tierra del Fuego, but also occurs as a nonbreeder in cold pelagic waters off both coasts.

70–85 cm (1 Shirihai, H. (2007). A Complete Guide to Antarctic Wildlife. The Birds and Mammals of the Antarctic Continent and the Southern Ocean. Second edition. A. & C. Black, London, UK. Close ); male 3096–4345 g, female 2840–4175 g (2 Brooke, M. (2004). Albatrosses and Petrels Across the World. Oxford University Press, Oxford, UK. Close ); wingspan 180–220 cm. Clearly hooded, but only indistinctly capped . Adult has grey hood , darkest next to eye as in other mollymawks but often less contrastingly browed, conspicuous and clear-cut white crescent framing lower and rear half of eye , forehead and forecrown  diffusely paler, but no capped pattern, often fading whiter on throat and foreneck, and neck can be paler grey as well, with dark brownish-grey mantle; back, scapulars and especially upperwing blackish brown , outer primaries with white shafts; tail grey; underwing white with broader blackish margins than most mollymawks , broadest on basal third of leading edge; breast  and rest of underparts white; iris dark brown to blackish; bill black with rich yellow on upper and lower ridges, orange-red on maxilla, yellow on mandible does not reach tip and forms narrow yellow basal line with thin black line at very base; gape rich yellow ; legs pale pinkish and pale bluish grey. Sexes similar, but female averages smaller in most measurements (2 Brooke, M. (2004). Albatrosses and Petrels Across the World. Oxford University Press, Oxford, UK. Close ). Bill colours form  unique pattern, but see T. chlororhynchos and T. bulleri; from former by strongly capped appearance, and from both by broader blackish leading edge to underwing; T. melanophris has similar underwing pattern, but bill colour and paler head/neck prevent confusion; underwing has less black at ‘wrist’ and ‘elbow’ than Phoebastria immutabilis. Juvenile has blackish bill and dark underwing, brownish-grey hood usually darker but less even on face, pale crescent framing rear of eye usually inconspicuous, and may have whitish areas on crown and face; separation from juvenile T. melanophris can be tricky, but present species usually has greyer head and darker bill base (2 Brooke, M. (2004). Albatrosses and Petrels Across the World. Oxford University Press, Oxford, UK. Close ).

• Gray-headed x Black-browed Albatross (hybrid) Thalassarche chrysostoma x melanophris

Circumpolar in Southern Ocean, breeding from Cape Horn E to Campbell I.

Marine and pelagic , rarely approaching land except at colonies; favours much colder surface waters than most other albatross species. Breeds on remote oceanic islands occupying steep slopes or cliffs, generally with tussock grass .

Disperses widely over Southern Ocean, mostly between 65° S and 35° S, reaching 15° S in zone of Humboldt Current. During non-breeding season South Georgia birds have been recorded making one or more global circumnavigations, the fastest in just 46 days, whereas all New Zealand-banded birds have been recovered W of New Zealand in Australian zone. Tracked birds from South Georgia spent during the non-breeding period a large proportion of time in the SW Atlantic, N of the colony between the Polar Front and the Subtropical Front, E of the Falkland Islands, and around the South Sandwich Fracture Zone, and they also foraged around the Subtropical Front in the SW Indian Ocean and NE of the Kerguelen Plateau towards the Southeast Indian Ridge; in contrast, similarly tracked  birds from the Prince Edward Islands spent a large proportion of time in the Indian Ocean, around the colony towards the Southwest Indian Ridge, and in the SE Indian Ocean between the Kerguelen Plateau and Southeast Indian Ridge, but they also foraged towards the Humboldt Upwelling, SE Pacific Ocean (3 Clay, T.A., Manica, A., Ryan, P.G., Silk, J.R.D., Croxall, J.P., Ireland, L. and Phillips, R.A. (2016). Proximate drivers of spatial segregation in non-breeding albatrosses. Scientific Reports 6, Article number: 29932. Close ). Among the birds form South Georgia, previously failed birds segregated spatially from successful birds during summer, when they used less productive waters, suggesting a link between breeding outcome and subsequent habitat selection (3 Clay, T.A., Manica, A., Ryan, P.G., Silk, J.R.D., Croxall, J.P., Ireland, L. and Phillips, R.A. (2016). Proximate drivers of spatial segregation in non-breeding albatrosses. Scientific Reports 6, Article number: 29932. Close ). One individual has been recorded traveling, during a regular foraging trip, at minimum average ground speed of >110 km/h for c. 9 hours (4 Catry, P., Phillips, R.A. and Croxall, J.P. (2004). Sustained fast travel by a Gray-headed Albatross (Thalassarche chrysostoma) riding an Antarctic storm. Auk. 121(4): 1208–1213. Close ). No reliable records from N Hemisphere; in S African region very rare even as far N as Namibia (5 Praetsch, F. and Boyer, D. (2002). First specimen record of the Grey-headed Albatross Diomedea chrysostoma for Namibia. Marine Orn.. 30(1): 45. Close ) and just one record in tropical Pacific, from Tahiti, French Polynesia (17º S) (6 Monnet, C. (1990). First record of a Greyheaded Albatross Diomedea chrysostoma in the tropical Pacific Ocean. Marine Orn.. 18(1–2): 57–59. Close ).

Mainly cephalopods (Todarodes, Kondakovia longimana, Histioteuthis eltaninae) and fish (Myctophidae, Channichthys rhinoceratus, Dysalotus alcockii); also crustaceans (Euphausia superba) and carrion; lampreys (Geotria australis) locally important. High proportion of squid in diet at South Georgia may account for longer nesting period than T. melanophris, which takes mostly krill; five cephalopod species belonging to five families (Gonatidae, Onychoteuthidae, Psychroteuthidae, Ommastrephidae and Cranchiidae) contributed 98% by number and 97% of biomass fed to chicks at South Georgia, where the most important species was the ommastrephid Martialia hyadesi, contributing 68·9–77·4% by number and 72·5–79·3% of total biomass (7 Rodhouse, P.G., Prince, P.A., Croxall, J.P. and Murray, A.W.A. (1990). Cephalopod prey of the grey-headed albatross Diomedea chrysostoma. Marine Biology. 104: 353–362. Close ). However, inter-annual variation in diet well-documented (8 Xavier, J.C., Croxall, J.P. and Reid, K. (2003). Interannual variation in the diets of two albatross species breeding at South Georgia: implications for breeding performance. Ibis. 145(4): 593–610. Close ), thus at same site, during unusually warm weather in Mar/Apr 2000, fed mainly on krill (Euphausia superba; 77% by mass) (9 Xavier, J.C., Croxall, J.P., Trathan, P.N. and Wood, A.G. (2003). Feeding strategies and diets of breeding grey-headed and wandering albatrosses at South Georgia. Marine Biology. 143: 221–232. Close ). Most food taken by surface-seizing, but also uses surface-diving and shallow-plunging to access some items (1 Shirihai, H. (2007). A Complete Guide to Antarctic Wildlife. The Birds and Mammals of the Antarctic Continent and the Southern Ocean. Second edition. A. & C. Black, London, UK. Close ), sometimes reaching up to 6 m (usually less than 1 m) (2 Brooke, M. (2004). Albatrosses and Petrels Across the World. Oxford University Press, Oxford, UK. Close ). Diving mostly occurs during daylight and this technique can yield up to 30–45% of daily food requirements (2 Brooke, M. (2004). Albatrosses and Petrels Across the World. Oxford University Press, Oxford, UK. Close ). Does not usually follow ships (except around Falkland Is) (1 Shirihai, H. (2007). A Complete Guide to Antarctic Wildlife. The Birds and Mammals of the Antarctic Continent and the Southern Ocean. Second edition. A. & C. Black, London, UK. Close ) and attends fishing boats less regularly than other species; regularly associates with other tubenoses (10 Harrison, N. M., M. J. Whitehouse, D. Heinemann, P. A. Prince, G. L. Hunt Jr., and R. R. Veit (1991). Observations of multispecies seabird flocks around South Georgia. Auk 108(4):801–810. Close , 11 Silverman, E.D. and Veit, R.R. (2001). Associations among Antarctic seabirds in mixed-species feeding flocks. Ibis. 143(1): 51–62. Close ) and cetaceans (e.g. killer whales Orcinus orca) (12 Williams, A. J., B. M. Dyer, R. M. Randall, and J. Komen (1990). Killer whales Orcinus orca and seabirds: “play”, predation and association. Marine Ornithology 18(1):37–41. Close ), except around New Zealand (1 Shirihai, H. (2007). A Complete Guide to Antarctic Wildlife. The Birds and Mammals of the Antarctic Continent and the Southern Ocean. Second edition. A. & C. Black, London, UK. Close ). Will congregate in larger groups at plentiful food source, but usually observed alone or in small groups (1 Shirihai, H. (2007). A Complete Guide to Antarctic Wildlife. The Birds and Mammals of the Antarctic Continent and the Southern Ocean. Second edition. A. & C. Black, London, UK. Close ).

Wailing and croaking calls like those of most other mollymawks, especially T. melanophris (1 Shirihai, H. (2007). A Complete Guide to Antarctic Wildlife. The Birds and Mammals of the Antarctic Continent and the Southern Ocean. Second edition. A. & C. Black, London, UK. Close ).

Biennial, when successful; starts early Sept–Oct with return to colony, thereafter pre-laying exodus (by females) lasts on average c. 16 days, egg-laying occupies c. 20 days at most colonies (mean date usually 20 Oct), hatching mostly early Dec and colony deserted by May (late Apr on Macquarie I) (13 Clarke, R.H. and Schulz, M. (2005). Land-based observations of seabirds off sub-Antarctic Macquarie Island during 2002 and 2003. Marine Ornithology 33(1):7–17. Close ), thus overall attendance at colony is c. 239 days (2 Brooke, M. (2004). Albatrosses and Petrels Across the World. Oxford University Press, Oxford, UK. Close ). Monogamous and pair-bonds probably life-long (1 Shirihai, H. (2007). A Complete Guide to Antarctic Wildlife. The Birds and Mammals of the Antarctic Continent and the Southern Ocean. Second edition. A. & C. Black, London, UK. Close ). Colonial, forming colonies of 15–10,000 pairs; large nest of mud  and grass, with central depression. Single whitish egg, marked with fine red spots at large end (1 Shirihai, H. (2007). A Complete Guide to Antarctic Wildlife. The Birds and Mammals of the Antarctic Continent and the Southern Ocean. Second edition. A. & C. Black, London, UK. Close ), mean size 106 mm × 68 mm, mass 276 g (2 Brooke, M. (2004). Albatrosses and Petrels Across the World. Oxford University Press, Oxford, UK. Close ); incubation c. 69–78 days (1 Shirihai, H. (2007). A Complete Guide to Antarctic Wildlife. The Birds and Mammals of the Antarctic Continent and the Southern Ocean. Second edition. A. & C. Black, London, UK. Close ) with stints of 5–15 days (first shifts long, later ones shorter) (2 Brooke, M. (2004). Albatrosses and Petrels Across the World. Oxford University Press, Oxford, UK. Close ); chicks have white or pale grey down, whitest on face, being fed every 1·26 days with mean meal size of 616 g (14 Huin, N., Prince, P.A. and Briggs, D.R. (2000). Chick provisioning rates and growth in Black-browed Albatross Diomedea melanophris and Grey-headed Albatross D. chrysostoma at Bird Island, South Georgia. Ibis. 142(4): 550–565. Close ); fledging mean c. 141 days when 3500–4000 g, but reaches peak mass of 3500–4900 g when c. 90 days old (2 Brooke, M. (2004). Albatrosses and Petrels Across the World. Oxford University Press, Oxford, UK. Close ). At Diego Ramírez Is (off Cape Horn), breeding adults undertake foraging trips of between 2500 km and 12,000 km (15 Robertson, G., Valencia, J., Moreno, C. and Wienecke, B. (2000). Foraging ranges of Islas Diego Ramirez albatrosses and potential interactions with fisheries. P. 145 in:. Close ), while on Marion I, during incubation, birds make long foraging trips, mostly towards subtropical convergence and subantarctic zones, whereas during early chick-rearing stage, foraging trips are shorter and to polar frontal and Antarctic zones, with males making higher proportion of short trips (16 Nel, D.C., Nel, J.L., Ryan, P.G., Klages, N.T.W., Wilson, R.P. and Robertson, G. (2000). Foraging ecology of grey-headed mollymawks at Marion Island, southern Indian Ocean, in relation to longline fishing activity. Biological Conservation. 96: 219–231. Close ). At South Georgia foraging trips can occupy up to 28 days (9 Xavier, J.C., Croxall, J.P., Trathan, P.N. and Wood, A.G. (2003). Feeding strategies and diets of breeding grey-headed and wandering albatrosses at South Georgia. Marine Biology. 143: 221–232. Close , 17 Catry, P., Phillips, R.A., Phalan, B. and Croxall, J.P. (2006). Senescence effects in an extremely long-lived bird: the grey-headed albatross Thalassarche chrysostoma. Proc. Royal Soc. London (Ser. B Biol. Sci.). 273: 1625–1630. Close ). Overall breeding success estimated at 58% on Macquarie I (18 Gales, R., Brothers, N. and Terauds, A. (2000). Endangered. The threatened albatrosses of Macquarie Island: conservation and threats. P. 130-131 in:. Close ) and 39% at South Georgia (just 28% in 1984) (19 Reid, K., Prince, P.A. and Croxall, J.P. (2000). Fly or die: the role of fat stores in the growth and development of Grey-headed Albatross Diomedea chrysostoma chicks. Ibis. 142(1): 188–198. Close ), where 60% of eggs hatch and 65% of chicks fledge (20 Prince, P.A., Rothery, P., Croxall, J.P. and Wood, A.G. (1994). Population dynamics of Black-browed and Grey-headed Albatrosses Diomedea melanophris and D. chrysostoma at Bird Island, South Georgia. Ibis. 136(1): 50–71. Close ); < 1% of successful birds breed the next year (versus 5% on Marion I) (21 Ryan, P.G., Phillips, R.A., Nel, D.C. and Wood, A.G. (2007). Breeding frequency in Grey-headed Albatrosses Thalassarche chrysostoma. Ibis. 149(1): 45–52. Close ), 68% return to breed two years later, 11% the next and 5% not until the fourth year, in contrast > 50% of birds that fail to rear a chick breed the next year, but 23% delay another year, and birds that fail later than March do not return next year, whereas 80% that fail during incubation do breed the following year (20 Prince, P.A., Rothery, P., Croxall, J.P. and Wood, A.G. (1994). Population dynamics of Black-browed and Grey-headed Albatrosses Diomedea melanophris and D. chrysostoma at Bird Island, South Georgia. Ibis. 136(1): 50–71. Close ). Sexual maturity at 8–14 years, although birds may first return to colonies at 3–5 years (more usually 6–7) (2 Brooke, M. (2004). Albatrosses and Petrels Across the World. Oxford University Press, Oxford, UK. Close ). Senescence appears to set in after age 28 years (17 Catry, P., Phillips, R.A., Phalan, B. and Croxall, J.P. (2006). Senescence effects in an extremely long-lived bird: the grey-headed albatross Thalassarche chrysostoma. Proc. Royal Soc. London (Ser. B Biol. Sci.). 273: 1625–1630. Close ). Adult mortality of c. 5–7% per year and at least some birds have been recorded living up to 44 years (17 Catry, P., Phillips, R.A., Phalan, B. and Croxall, J.P. (2006). Senescence effects in an extremely long-lived bird: the grey-headed albatross Thalassarche chrysostoma. Proc. Royal Soc. London (Ser. B Biol. Sci.). 273: 1625–1630. Close ), while survival of fledglings to breeding age at South Georgia was estimated at 35–36% (1959–1964 cohorts), although this subsequently crashed to just 7–8% (1976–1981) and probably reached below 5% (1982–1986) (2 Brooke, M. (2004). Albatrosses and Petrels Across the World. Oxford University Press, Oxford, UK. Close ). At Macquarie, juvenile survival was estimated at 33·6% between 1975 and 2000 (22 Terauds, A., Gales, R. and Alderman, R. (2005). Trends in numbers and survival of Black-browed (Thalassarche melanophrys) and Grey-headed (T. chrysostoma) Albatrosses breeding on Macquarie Island. Emu. 105(2): 159–167. Close ).

ENDANGERED. World population estimated at c. 500,000–600,000 birds in late 1990s, with c. 80,000–95,000 pairs breeding in any one year; 17,000 pairs on Diego Ramírez Is (2002, where numbers apparently increasing) (23 Robertson, G., Moreno, C.A., Lawton, K., Arata, J., Valencia, J. and Kirkwood, R. (2007). An estimate of the population sizes of Black-browed (Thalassarche melanophrys) and Grey-headed (T. chrysostoma) Albatrosses breeding in the Diego Ramírez Archipelago, Chile. Emu. 107(3): 239–244. Close ), formerly 61,500 pairs at South Georgia including Bird I and Willis Is (2 Brooke, M. (2004). Albatrosses and Petrels Across the World. Oxford University Press, Oxford, UK. Close ) (but population estimated to have declined by 25% since 1977, leading to revised estimate of 47,700 pairs in 2004) (24 Clarke, A., J. P. Croxall, S. Poncet, A. R. Martin, and R. Burton (2012). Important Bird Areas: South Georgia. British Birds 105(3):118–144. Close ), 6400 pairs (2 Brooke, M. (2004). Albatrosses and Petrels Across the World. Oxford University Press, Oxford, UK. Close ) at Campbell I (formerly 11,530 pairs, major decline between 1940s and 1997 but numbers have apparently stabilized since) (25 Waugh, S.M., Weimerskirch, H., Moore, P.J. and Sagar, P.M. (1999). Population dynamics of Black-browed and Grey-headed Albatrosses Diomedea melanophrys and D. chrysostoma at Campbell Island, New Zealand, 1942–96. Ibis. 141(2): 216–225. Close ); c. 20,000 pairs in S Indian Ocean at Kerguelen (7900 pairs), Crozet (5940 pairs) and Prince Edward Is (7700 pairs, where increasing on Marion I) (26 Crawford, R.J.M., Duncombe Rae, C.M., Nel, D.C. and Cooper, J. (2003). Unusual breeding by seabirds at Marion Island during 1997/98. African Journal of Marine Science. 25(1): 453–462. Close , 27 Crawford, R.J.M., Cooper, J., Dyer, B.M., and others (2003). [Full list of authors: Crawford, R.J.M., Cooper, J., Dyer, B.M., Greyling, M.D., Klages, N.T.W., Ryan, P.G., Petersen, S.L., Underhill, L.G., Upfold, L., Wilkinson, W., De Villiers, M.S., Du Plessis, S., Du Toit, M., Leshoro, T.M., Makhado, A.B., Mason, M.S., Merkle, D., Tshingana, D., Ward, V.L. & Whittington, P.A.] Populations of surface-nesting seabirds at Marion Island, 1994/95–23973972/3973. Afr. Journal Mar. Sci. 25(1): 427–440. Close , 28 Ryan, P.G., Cooper, J., Dyer, B.M., Underhill, L.G., Crawford, R.J.M. and Bester, M.N. (2003). Counts of surface-nesting seabirds breeding at Prince Edward Island, summer 284841/842. Afr. Journal Mar. Sci. 25(1): 441–451. Close ); only very small numbers on Macquarie I (78 pairs in 1998/99 and population apparently stable since mid 1970s) (29 Baker, G. B., R. Gales, S. Hamilton, and V. Wilkinson (2002). Albatrosses and petrels in Australia: a review of their conservation and management. Emu 102(1):71–97. Close , 22 Terauds, A., Gales, R. and Alderman, R. (2005). Trends in numbers and survival of Black-browed (Thalassarche melanophrys) and Grey-headed (T. chrysostoma) Albatrosses breeding on Macquarie Island. Emu. 105(2): 159–167. Close ). In early 20th century egg collecting produced significant decline, but nowadays only occurs very rarely. Numbers apparently fairly stable at most breeding stations but significant recent decline at South Georgia (20 Prince, P.A., Rothery, P., Croxall, J.P. and Wood, A.G. (1994). Population dynamics of Black-browed and Grey-headed Albatrosses Diomedea melanophris and D. chrysostoma at Bird Island, South Georgia. Ibis. 136(1): 50–71. Close ); slight local decreases especially connected with habitat destruction and predation by alien mammals, e.g. cats, rats, but also due to launch of squid fishery and longline fishing for Patagonian toothfish (Dissotichus), although only comparatively small numbers were taken off SW Argentina in 1999–2001 (30 Favero, M., Khatchikian, C.E., Arias, A., Silva Rodriguez, M.P., Cañete, G. and Mariano-Jelicich, R. (2003). Estimates of seabird by-catch along the Patagonian Shelf by Argentine longline fishing vessels, 1999–211106111061. Bird Conservation International. 13(4): 273–281. Close ). Mortality (especially of immatures) has increased at commercial fishing grounds, especially off South Africa (31 Barnes, K., Boix, C. and Ryan, P. (1997). Longlining – southern African seabirds on the hook again. Bull. African Bird Club. 4(1): 9. Close ), Australia (32 Klaer, N. and Polacheck, T. (1997). By-catch of albatrosses and other seabirds by Japanese longline fishing vessels in the Australian Fishing Zone from April 1992 to March 1995. Emu. 97(2): 150–167. Close ) and in S Indian Ocean (33 Cherel, Y., H. Weimerskirch, and G. Duhamel (1996). Interactions between longline vessels and seabirds in Kerguelen waters and a method to reduce seabird mortality. Biological Conservation 75:63–70. Close , 34 Ryan, P.G. (1999). Sexual dimorphism, moult and body condition of seabirds killed by longline vessels around the Prince Edward Islands, 1996–97. Ostrich. 70(3–4): 187–192. Close , 35 Nel, D.C., Cooper, J. and Ryan, P.G. (2000). Spatial interactions of albatrosses breeding on Marion Island with longline fisheries in the southern Indian Ocean: species, gender and seasonal effects. Marine Orn.. Pp. 138–139 in:. Close ), where most die incidentally, although mitigation factors have now been developed (36 Klaer, N. and Polacheck, T. (1998). The influence of environmental factors and mitigation measures on by-catch rates of seabirds by Japanese longline fishing vessels in the Australian region. Emu. 98(4): 305–316. Close , 37 Ryan, P.G. and Watkins, B.P. (2002). Reducing incidental mortality of seabirds with an underwater longline setting funnel. Biological Conservation. 104: 127–131. Close ); at South Georgia, less affected by competition with fisheries than is T. melanophris.