THE SOOTY SHEARWATER. 435 



mottling and markings ; tail-feathers black-brown ; wing-feathers 

 same but imier webs paler brown and tips and outer webs with 

 more or less grey bloom ; wing- coverts as upper -parts. This 

 plumage is acquired by complete moult Feb .-Sept. or even Oct. 

 N.B. — In worn plumage of a more rusty tinge of brown not so 

 blackish. 



Nestling. — One in Tring Mus. (New Zealand, Sir W. Buller) 

 showing both downs, is like nestling Manx Shearwater. A little 

 down remaining on a young feathered bird is, however, rather 

 darker with a greyish-sooty tinge. 



Juvenile. — Apparently like adult. 



Measurements and structure. — $ wing 290 (one 270, one 280)- 

 310 (one 320) mm., tail 84-98, tarsus 52-60, middle toe with claw 

 61-68, bill from feathers 39-44 (14 measured). ? wing 280 (one 

 273)-305, bill 38-44. Primaries : 1st narrow, pointed and about 

 two -thirds primary-coverts, 2nd longest, 3rd 5-8 mm. shorter 

 (exceptionally as long), 4th 16-25 shorter, 5th 40-50 shorter, 6th 

 65-75 shorter. Rest of structure as Manx Shearwater. 



Soft parts. — Bill dark grey, dark brown to purplish-black, 

 paler on ridge of culmen ; legs and feet slate -grey, outer side of 

 tarsus and outer toe dark grey or blackish, webs dark grey or yel- 

 lowish ; iris black-brown. 



Characters. — No subspecies. Grey-brown under -parts and large 

 size distinguish it from other British Puffinus. 



Field -characters. — An all dark sooty-brown bird with black bill 

 and feet and short tail, smaller than P. kuhlii and more elegant and 

 slender. Flight conforms to that characteristic of smaller members 

 of Shearwater group rather than to such species as P. kuhlii. 

 (P. R. Lowe.) 



Breeding-habits. — Nests in burrow, 3 or 4 ft. long in peaty ground. 

 Nest. — Consists only of a few twigs and dead leaves. Egg. — One 

 only, white. Average of 10 eggs, 75.8x49. Max. : 81x49 and 

 75.6x51. Min. : 71.5x49.5 and 74.9x45.4 mm. Breeding-season. 

 — Nov. and Dec. Incubation. — Apparently shared by both sexes 

 as males have been taken on eggs. Period not ascertained. 



Food. — No definite records. 



Distribution. — British Isles. — Autumn-visitor (Aug.-Oct., ex- 

 ceptionally Nov. and Dec). Chiefly noticed off Firth of Forth, 

 coast Yorks., along Channel from Kent to Cornwall, and off coasts 

 Cork, Kerry, and Mayo. Also recorded Northumberland (four and 

 others seen), several Outer Hebrides, two Orkneys, and once each 

 from coasts Haddington, Norfolk, Down. 



Distribution. — Abroad. — Breeds in Southern Hemisphere (New 

 Zealand and neighbouring islands), ranging north after breeding- 

 season to Faeroes and United States, as well as to Kuriles and south 

 Alaska. Said to nest on Pescadores near Formosa, but this requires 

 confirmation. 



