413 A PRACTICAL HANDBOOK OF BRITISH BIRDS. 



4th 2-6 shorter, 5th 15-20 shorter, 6th 24-32 shorter. Tail very 

 slightly forked. Tarsus very long. Claws rather flat. Bill short 

 but comparatively broad at base. Rest of structure as in Storm - 

 Petrel. 



Soft parts. — Bill, legs and feet black, webs black with broad 

 orange streak margined with black and extending from near base 

 for about three -fourths of length, longer on outer web ; iris deep 

 brown. 



Characters and allied forms. — 0. o. exasperatus (N. Zealand) 

 appears to be larger but measurements overlap. Long tarsus, 

 comparatively short bill, yellow webs and pure white upper tail- 

 co verts distinguish species. 



Field -characters. — Small black Petrel with apparent size of 

 Leach's and with white rump but square tail. Wavering flight 

 compared by Murphy to that of a Goat -sucker (Chordeiles). Legs 

 and toes comparatively longer than in Leach's and in flight protrude 

 nearly half an inch beyond tail. When flying low over water in 

 search of food often patters with feet on surface. (P. R. Lowe.) 



Breeding-habits. — On Kerguelen breeds under stones and bould- 

 ers, sometimes scratching away an entrance : depth of cup of typical 

 nest -hole about 5 in., while a rough nest was built of Azorella stalks 

 (R. Hall). In the S. Orkneys eggs were laid in narrow clefts and 

 fissures of rock, often far in, at varying heights in face of cliffs or 

 under stones : no nest being made. Egg. — One only, white, without 

 gloss, elongated in shape, sometimes with fine brown specks round 

 large end. Average of 16 eggs 33.3x23.6. Max.: 36x24. Min. : 

 32x23 and 32.7x22.7 mm. Breeding -season. — Jan. and Feb. in 

 Kerguelen : and from Dec. 11 onwards on S. Orkneys. Incubation. 

 — Apparently by both sexes : male caught on egg at 7 a.m. (Hall). 

 Period not ascertained. Single brooded. 



Food. — Small fishes, mollusca, Crustacea, marine plants and 

 floating oil (Audubon), also refuse thrown away after cleaning 

 fish. 



Distribution. — British Isles. — Very rare vagrant. England. — 

 Many seen off Land's End, May, 1838. Following authentic 

 examples since obtained : Cornwall (one), Wilts, (one), Isle of Wight 

 (two), Sussex (two), Yorks. (one), Cumberland (three). Scotland. — - 

 One, Jura (I. Hebrides), Oct., 1891. Ireland. — Two, Lough Erne 

 (Antrim), and Mossvale (Down), Oct. 1 and 2, 1891. 



Distribution. — Abroad. — Breeds on Kerguelen and S. Georgia Is. 

 and apparently in South Polar regions, migrating northwards 

 during antarctic winter as far north as British Isles and Labrador, 

 having been found in all seas except north Pacific. A subspecies 

 from New Zealand and Australia has been separated, but requires 

 confirmation. This form would breed on coast S. Polar continent L 

 (See Mathews, B. Austr., n, p. 11, 1912.) 



