Mottled Petrel Pterodroma inexpectata Scientific name definitions

32–36 cm (1 Howell, S. N. G. (2012). Petrels, Albatrosses, and Storm-Petrels of North America: A Photographic Guide. Princeton University Press, Princeton, New Jersey, USA. Close ); 247–441 g; wingspan 74–92 cm (1 Howell, S. N. G. (2012). Petrels, Albatrosses, and Storm-Petrels of North America: A Photographic Guide. Princeton University Press, Princeton, New Jersey, USA. Close ). A rather short-billed and short-tailed  grey petrel with dark M pattern  on upperparts, bold underwing pattern  , white throat and undertail-coverts. Forehead and foreface  , including anterior superciliary and lower ear-coverts, mostly white, most of rear face, cap and nape down to neck-sides and lower back, grey, blackish on patch through the eye, scapulars and base of upperwing concolorous with mantle, rest of upperwing grey except darker brown-grey band forming M  pattern on outer primaries and their coverts, distal and central marginal and lesser coverts, central median and innermost greater coverts and tertials, meeting on rump, greater and median coverts sometimes obviously paler  forming large panel on rear half of inner wing, uppertail-coverts grey, sometimes paler than back, uppertail grey to dark grey; pale fringes afford upperparts scaly look in fresh plumage; underwing white with narrow dark grey margin outlining primaries and secondaries, narrowest on inner primaries, broad black band over carpal continues as diagonal bar to central inner wing; throat white, foreneck speckled grey, central breast mostly white, grey or grey-brown on belly, breast-sides and flanks, becoming grey speckled or vermiculated towards axillaries and vent  , central abdomen often has some pale spotting, undertail-coverts white; iris dark brown; bill  black; legs and base of feet pale fleshy pink, rest of feet blackish. Sexes alike, but females average marginally shorter-tailed than males (2 Brooke, M. (2004). Albatrosses and Petrels Across the World. Oxford University Press, Oxford, UK. Close ). Juvenile similar to adult but has more noticeable pale scaling above and more extensive whitish on outer rectrices (May–Jul at least) (1 Howell, S. N. G. (2012). Petrels, Albatrosses, and Storm-Petrels of North America: A Photographic Guide. Princeton University Press, Princeton, New Jersey, USA. Close ). Upperparts similar to those of several other Pterodroma, but underparts  mainly white (including undertail-coverts) contrasting with bold dark underwing bar and grey belly.

Pacific Ocean, breeding in New Zealand on SW South I, Solander I, islands around Stewart I, and Snares Is.

Marine and highly pelagic , rarely approaching land except at colonies. Breeds on islets  and stacks, occupying rocky ground or tussock grassland, or fringes of Olearia woodland (2 Brooke, M. (2004). Albatrosses and Petrels Across the World. Oxford University Press, Oxford, UK. Close ), up to 350 m above sea-level.

Transequatorial migrant. During breeding season, common S to pack ice zone near Antarctica; probably main foraging area for nesting adults. After breeding, quickly moves N, passing through Hawaiian waters between Feb and Jun (2 Brooke, M. (2004). Albatrosses and Petrels Across the World. Oxford University Press, Oxford, UK. Close , 1 Howell, S. N. G. (2012). Petrels, Albatrosses, and Storm-Petrels of North America: A Photographic Guide. Princeton University Press, Princeton, New Jersey, USA. Close ), to Bering Sea (in waters of 5–10·9ºC) (2 Brooke, M. (2004). Albatrosses and Petrels Across the World. Oxford University Press, Oxford, UK. Close ), where concentrates off Aleutian Is and in Gulf of Alaska, to 59º N, and is present May–Oct (mainly Jun–Oct) (1 Howell, S. N. G. (2012). Petrels, Albatrosses, and Storm-Petrels of North America: A Photographic Guide. Princeton University Press, Princeton, New Jersey, USA. Close ), exceptionally from third week of Apr (4 Day, R. H. (2006). Seabirds in the northern Gulf of Alaska and adjacent waters, October to May. Western Birds 37(4):190–214. Close ); uncommon off W coast of North America (mainly Feb–Apr), although 100s may pass through waters off British Columbia in late Apr (1 Howell, S. N. G. (2012). Petrels, Albatrosses, and Storm-Petrels of North America: A Photographic Guide. Princeton University Press, Princeton, New Jersey, USA. Close ). Moves S again through Hawaiian waters in Oct–Nov (2 Brooke, M. (2004). Albatrosses and Petrels Across the World. Oxford University Press, Oxford, UK. Close ), with records off W coast of North America between late Oct to Dec (mainly mid Nov to mid Dec), especially in cold-water years, and usually > 370 km offshore at latitude of California (1 Howell, S. N. G. (2012). Petrels, Albatrosses, and Storm-Petrels of North America: A Photographic Guide. Princeton University Press, Princeton, New Jersey, USA. Close ). A few records off extreme South America, mainly dating from times when more abundant, although there are recent records SE of Cape Horn (Dec 1993) (5 Meltofte, H. and Horneman, C. (1995). Mottled Petrel Pterodoma inexpectata off Tierra del Fuego. Bull. Brit. Orn. Club. 115(1): 71–72. Close ) and the Falkland Is (6 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 ). One record from NW Atlantic, inland in New York, USA (early Apr 1880) (1 Howell, S. N. G. (2012). Petrels, Albatrosses, and Storm-Petrels of North America: A Photographic Guide. Princeton University Press, Princeton, New Jersey, USA. Close ). Infrequently recorded in Australian waters (7 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 ).

Mostly squid and fish; also some crustaceans. Analysis of 69 stomachs reported dietary composition (by weight) as 20% cephalopods, 42% fish (mainly myctophids), 30% crustacea and 8% tunicates (2 Brooke, M. (2004). Albatrosses and Petrels Across the World. Oxford University Press, Oxford, UK. Close ). Feeds by surface-plunging, pursuit-plunging (6 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 surface-seizing, although hovering like storm-petrel also reported (2 Brooke, M. (2004). Albatrosses and Petrels Across the World. Oxford University Press, Oxford, UK. Close ). Sometimes associates with Ardenna grisea and Pterodroma mollis (6 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 ). Rarely follows ships and is generally recorded alone or in small groups at sea (6 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 ). Off-duty incubating birds typically feed in Antarctic waters of 0·7–2ºC and between 2200 km and 4000 km S of colony (2 Brooke, M. (2004). Albatrosses and Petrels Across the World. Oxford University Press, Oxford, UK. Close ).

Main call, far-carrying, hysterical-sounding “ti-ti-ti...”, has 8–15 syllables and is given either in the air, as males chase females, or from the ground; can also utter “gor-wik”, either in alone or in association with previous call, and pairs calling from the ground may duet using both; various, deeper-pitched growling and crooning noises, e.g. “quurrr, quurrr” or “goo-oo”, have been heard from birds in burrows (2 Brooke, M. (2004). Albatrosses and Petrels Across the World. Oxford University Press, Oxford, UK. Close , 6 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 ). Not known to call at sea (6 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 ).

Starts Oct, with pre-laying exodus suspected to last 9–16+ days and egg-laying usually commencing around end of first week of Dec, with two-thirds of eggs laid between 15 and 22 Dec, hatching period typically extending over c. 3 weeks (mean 7 Feb) and fledging in early May (2 Brooke, M. (2004). Albatrosses and Petrels Across the World. Oxford University Press, Oxford, UK. Close ). Monogamous with long-lasting pair-bonds (6 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 ). Strictly nocturnal at nest-sites and shows strong faithfulness to burrows, with at least 95% of birds returning to same site in subsequent seasons during one study (2 Brooke, M. (2004). Albatrosses and Petrels Across the World. Oxford University Press, Oxford, UK. Close ). Forms dense colonies; nests in burrows (c. 1 m long) (2 Brooke, M. (2004). Albatrosses and Petrels Across the World. Oxford University Press, Oxford, UK. Close ) or rock crevices. Single white egg, mean size 58·6 mm × 42·7 mm, mass 61·1 g (2 Brooke, M. (2004). Albatrosses and Petrels Across the World. Oxford University Press, Oxford, UK. Close ); incubation c. 50 days (range 48–53 days) (6 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 12–14 days (typically longer by female) (2 Brooke, M. (2004). Albatrosses and Petrels Across the World. Oxford University Press, Oxford, UK. Close ); chicks  have grey down, brooded for 1–2 days (2 Brooke, M. (2004). Albatrosses and Petrels Across the World. Oxford University Press, Oxford, UK. Close ); fledging 90–105 days, but few data on chick growth or feeding rates, although one chick almost doubled its weight, from 360 g to 715 g, with one meal at 29 days (2 Brooke, M. (2004). Albatrosses and Petrels Across the World. Oxford University Press, Oxford, UK. Close ). No other data, e.g. on nesting success or life expectancy.

Not globally threatened. Currently considered as Near Threatened. Total population was formerly estimated at 10,000–50,000 breeding pairs, but more recently at 1,500,000 birds, with perhaps 300,000–400,000 pairs on Codfish I, off Stewart I, alone (in 1996), where Wekas (Gallirallus australis) were eradicated in 1984 and black rats (Rattus rattus) in 1998, with an additional 10,000+ pairs in the Snares group (2 Brooke, M. (2004). Albatrosses and Petrels Across the World. Oxford University Press, Oxford, UK. Close ). Formerly much more numerous and widespread, with breeding on North I and South I, New Zealand, where affected by forest clearance, and on Chatham, Bounty, Antipodes and Auckland Is. Local extinction from these island groups mainly due to predation by mammals introduced by both Polynesians and Europeans, and Wekas, and by harvesting for human consumption (e.g. by Maoris) (2 Brooke, M. (2004). Albatrosses and Petrels Across the World. Oxford University Press, Oxford, UK. Close ). Elimination of alien predators from present and former breeding stations advisable in order to maintain present numbers and encourage recolonization of former range. Extreme El Niño events may lead to large numbers of birds washing ashore dead (8 Taylor, G.A. (2004). Beach patrol scheme: seabirds found dead on New Zealand beaches, 1997 - 1999. Notornis 51(3):176–191. Close ).