THE BLACK-BBOWED ALBATBOS. 447 



becoming blackish on longer scapulars, feathers margined slightly 

 paler (in worn plumage tips become whitish-brown on mantle) ; 

 rump and upper tail -coverts white ; under -parts white ; axillaries 

 white some tinged grey basally ; under wing-coverts white or 

 greyish -white in centre with broad margin round edges of wing 

 brown -grey ; tail-feathers grey, when fresh with silvery tinge 

 especially on outer webs, shafts white ; wing-feathers with outer 

 webs and tips dark grey-brown, inner webs silvery-grey, shafts 

 pale yellow basally ; all wing-coverts dark (often blackish) grey as 

 scapulars. This plumage is acquired by complete moult Jan.- 

 July and probably later. 



Nestling . — (Not examine d . ) 



Measurements and structure. — £ wing 50.5-54 cm., tail 185- 

 210 mm., tarsus 80-95, middle toe with claw 115-130, bill from 

 feathers 115-125 (10 measured). $ wing 49-53 cm., bill 105-120 mm. 

 Primaries : 1st narrow, pointed and hidden by primary- coverts, 

 2nd longest, 3rd 5-20 mm. shorter, 4th 30-45 shorter, 5th 60-90 

 shorter ; outer web of 2nd much narrower than in rest. Secondaries 

 short, tips gently sloped off on outer webs. Tail slightly rounded, 

 12 feathers, tips slightly rounded. Bill large, deep, compressed, and 

 strong, ridge of culmen somewhat concave, tip abruptly decurved 

 and sharply pointed, lower mandible with no groove on side, but 

 the two rami joined at their distal ends with a separate piece 

 projecting below the under line of the mandible. Nostrils with 

 short and semi -tubular opening projecting upwards and slightly 

 forwards on sides of upper mandible near its base. Tarsus short, 

 toes long and somewhat slender, no hind toe, claws short, broad, 

 and rounded. 



Soft parts. — Bill yellow, tip orange (adult), blackish or with 

 blackish tip (" young ") ; legs and feet flesh-grey darker on joints 

 and webs, claws yellow-horn ; iris brown. 



Chabactebs. — Several forms have been separated but do not seem 

 to be satisfactory. Colour, large size, long narrow wings, large, 

 deep, hooked bill with short nasal tubes on sides at once distinguish 

 species from other birds on British list. 



Bbeeding-habits. — Breeds in large colonies up to 1800 ft. on 

 islands. Nest. — Earth and moss obtained from ground near and 

 thus forming a trench round nest, which is raised to a height of 

 4 inches or so. Egg. — One only, but 2 said to have occurred, white 

 with a few red-brown spots, chiefly at big end. Average of 8 eggs, 

 103.9x62.6. Max.: 108.5x65 and 113x68. Min. : 96x63 and 

 97x53.5 mm. Breeding -season. — Nov. and Dec. Incubation. — By 

 female alone. Period about 60 days during which she does not 

 leave nest, but is fed by her mate. Single brooded. 

 Food. — Cephalopoda (cuttle-fish), and according to Saunders also 

 medusae and mollusca, as well as floating refuse from ships. Remains 

 of a Diving Petrel have been found in stomach, and it is said to 

 force other birds, especially Great Shearwater, to disgorge food. 



