Also Pacific Albatross
Taxonomy |
Before now, two subspecies of Buller's Albatross were recognized: Diomedea bulleri bulleri which breeds on the Solander Island (4,000-5,000 prs, southern tip of New Zealand) and the Snares Islands (8,500 prs, due south of New Zealand) and Diomedea bulleri platei which breeds on the Chatham Islands (18,000 prs, east of New Zealand) with a smaller number on Three Kings Island (less than 20 prs, at the northern tip of New Zealand). Thus Platei (estimated at 100,000 individuals) is twice as numerous as bulleri (estimated at 50,000 individuals). Heather and Robertson (1997) refer to these as Southern and Northern Buller's Albatross respectively. Platei starts breeding in October (eggs layed in November) while bulleri starts in December, the eggs being laid in January-February (Gales, 1998). Importantly, both forms are under severe threat from commercial (long-line) fishing.
Note: Robertson and Nunn (1998) have proposed elevating D. b. platei to full species status. Possibly naming the new form the PACIFIC ALBATROSS. This move is based primarily on a different timing of the breeding season, longer incubation stints by bulleri.
Nominate bulleri
tends to winter in the seas surrounding southern New Zealand and westwards to
Tasmania and southeastern Australia. Platei on the other hand ranges
much further eastwards, crossing the south Pacific to reach the Humbolt Current
off Chile and Argentina. Presumably this propensity to cross the Pacific is
behind the proposed new English name. It is unclear to me how absolute this
range division is and I imagine further study is needed. For example, a bird
banded as a chick on the Snares (thus presumably nominate Buller's?) was taken
in the central Pacific some 2000 km SW of the Galapagos Islands (Warham, 1982).
Buller's Albatross has been recorded in the south Atlantic (off the Falkland
Islands in 1987 and Cape Town, South Africa in 1995) but I have no information
as to which form was involved.
Identification |
Buller's Albatross belongs to the complex group of mid-sized Albatross that have a white body and gray hood. These include Shy, Salvin's, Buller's, Pacific, White-capped, Gray-headed, Yellow-nosed and Chatham Albatrosses.
Adult B. b. platei differ from nominate Buller's Albatross in the following features:
(1) The forehead and forecrown is silvery-gray rather than white. However, this appears white in direct light and pale pearly gray in overcast conditions (Marchant and Higgins, 1990). Based on the painting (Plate 22) in Marchant and Higgins (1990), the difference in forehead color is very slight.
(2) Gray-black supercilium extends two-thirds of the way across the lores before merging into the dark gray at the base of the bill (Marchant and Higgins, 1990).
(3) The head and neck (hood) is slightly darker than adult bulleri (Marchant and Higgins, 1990).
(4) The bill is wider (Marchant and Higgins, 1990), but I wonder whether this is of any use in the field? It has been claimed that the yellow stripe on the mandibular rami (i.e. the lower plate of lower mandible) is narrower in bulleri but this may be rather variable (McCallum et al., 1985).
(5) In dried specimens at least, the feet and legs tend to be darker (Marchant and Higgins, 1990; Heather and Robertson, 1997). What about in life?
Juveniles B. b. platei differ from nominate Buller's Albatross in the following features:
(1) Supercilium as extensive as adults (Marchant and Higgins, 1990).
(2) Head and hindneck slightly darker (Marchant and Higgins, 1990).
Immature plumages: undescribed
(Marchant and Higgins, 1990)!
Where and When |
D. b. bulleri -- Pelagic trips from Wollongong, Australia; ferry to Stewart Island, NZ across Foveaux Strait
D. b. platei -- Pelagic
trips from Kaikoura, New Zealand; ferry across Cook Strait; ferry to Stewart
Island across Foveaux Strait; pelagics off Chile
Photos and information on the web |
Chambers (1989) p59. (adult paddling on water, no details) [Nominate bulleri??, pale hood, broad yellow stripe on mandibular rami, moderate amount of black in front of eye]
Enticott and Tipling (1997) p.35 panel 5. Adult in flight, November, New Zealand. [Platei??]
Enticott and Tipling (1997) p.35 panel 6. Adult paddling on water, April, New Zealand. [Platei?? Dark hood, limited yellow stripe on mandibular rami]
Harper and Kinsky (1978) frontispiece. Dramatic head on shot of adult on Chatham Island. [Platei based on location and sharply contrasting hood. The forehead appears snowy white! Can't judge the width of the mandibular rami stripe]
Harper and Kinsky (1978) p22. Adult in flight on Chatham Islands. [Platei based on location, dark gray hood, light-gray forehead/cap and very narrow yellow mandibular rami stripe]
Harrison (1996) p. 39, panel 80 [Nominate bulleri?? pale hood, broad yellow stripe on mandibular rami]
Harrison (1996) p. 39, panel 79 [Nominate bulleri?? pale hood, broad yellow stripe on mandibular rami]
Warham (1990) p. 237. Black and white photo of pair copulating, location unknown but I would guess at Snares Islands [Nominate bulleri?? pale hood with little contrast, broad yellow stripe on mandibular rami]
Robertson and Gales (1998)
p2. A fantastic side profile of the head and bill of an adult on the Chatham
Islands. [Platei based on location, dark gray hood, light-gray forehead/cap
and very narrow yellow mandibular rami stripe]
Acknowledgement |
Many thanks to Lysle Brinker
for generously allowing me to use his photos.
Literature |
Enticott, J. and Tipling,
D. (1997) Seabirds of the World: The complete reference. Stackpoll Books
Gales R. (1998) Albatross populations: status and threats. In 'Albatross Biology
and Conservation'. (Eds. Robertson, G. and Gales, R.) Chp 3, p 20-45. Surrey
Beatty and Sons Ltd.
Harper, P. C. and Kinsky, F.C. (1978) Southern Albatrosses and Petrels: an identification
guide. Victoria University Press.
Harrison P. (1996) Seabirds of the World: A photographic guide.
Heather, B. and Robertson, H. (1997) Field Guide to the Birds of New Zealand.
Oxford University Press.
McCallum, J. et al., (1985) Notornis 32: 257-259.
Marchant S. M. and Higgins, P. J. (1990) Handbook of Australian, New Zealand
and Antarctic Birds. Vol 1A. Oxford University Press.
Robertson, C. J. R. and Nunn, G. B. (1998) Towards a new taxonomy for albatrosses.
In 'Albatross Biology and Conservation'. (Eds. Robertson, G. and Gales, R.)
Chp 2, p 13-19. Surrey Beatty and Sons Ltd.
Warham, J. (1982) A distant recovery of Buller's Mollymawk. Notornis 29:
213-214.
Warham, J. (1990) The Petrels: Their ecology and Breeding Systems. Academic
Press.
Copyright © 1998 All
rights reserved Angus Wilson
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