372 A PRACTICAL HANDBOOK OF BRITISH BIRDS. 



black wing, sooty-brown in females and young birds, and acuminate 

 tail distinguish 0. n. nigra from allied species. 



Field -characters. — Except in nesting season seldom seen on 

 inland waters, but from autumn to spring common on most parts 

 of coast, where some remain during summer. Scattered birds in 

 small parties may be seen diving for food usually at some distance 

 from shore and these pack at times in immense flocks. Despite 

 its heavy build is very buoyant, riding lightly on water in roughest 

 weather or taking short nights with rapid wing-beats just clear of 

 waves. Male is unmistakable ; plumage entirely black, relieved 

 only by patch of apricot yellow on bill ; short pointed tail elevated 

 like Pintail's when bird is swimming. Grey cheeks coupled with 

 her bulky build identify the brown female. Call a hoarse " kr-r-r-r " 

 similar to that of many diving ducks. Male has a double note 

 " tuk-tuk " (second syllable strongly accented), which when 

 uttered by many birds in chorus comes in from the sea as a pleasing 

 murmur. In autumn I have heard this chorus punctuated by a 

 littering cry. Cordeaux mentions another note, a soft, musical 

 whistle " peu-peu-peu " like the call of a Wader. 



Breeding-habits. — Haunts lakes on moors or tundra. Nest. — 

 Generally near water or on island, well lined with sooty- brown 

 down, showing indistinct light centres (feathers from nest see 

 Brit. Birds, n, PL 2), mixed with lichens, moss, etc., in hollow 

 among heather. Eggs. — Usually 5 to 8, but 9-10 on record, creamy 

 to buff. Average of 100 eggs, 65.2 x 44.9. Max. : 72 x 44.3 and 64.1 

 X47.5. Min. : 59x42.5 and 60.9x42 mm. Breeding -season. — 

 Usually early June ; occasionally late May in Scotland. Incuba- 

 tion. — By female alone. Period 4 weeks ; once 32 days. Single 

 brooded. 



Food. — At sea mainly mollusca, especially mussels (Mytilus edulis), 

 also Cardium, Solen, Margarita, etc. On freshwater besides 

 mollusca (Anodonta, etc.), worms, insects and small fish, and roots 

 of waterplants (Potamogeton, etc.). Grain and beans washed out 

 of wrecks also recorded and small Crustacea (sandhoppers and 

 shrimps). 



Distribution. — British Isles. — Resident, passage - migrant and 

 winter-visitor (early Sept.-end Oct. to end April-early June). 

 Breeds Caithness, Sutherland, Cromarty, and parts of Ross 

 and Inverness, also in 1921 near Loch Tummel (Perths.), 

 said to have bred Tiree, 1897, bred Shetland, 1911, and one 

 pair has bred in a lough in Ireland since 1905 (probably 1904) 

 (cf. Brit. B., ii, pp. 39, 86, 134 ; m, p. 197 ; iv, p. 154 ; v, p. 79), 

 17 pairs 1918, 7 pairs 1919 (op. c, xn, p. 215 ; xiii, p. 87), has also 

 bred on another Irish lough. Common winter-visitor (young birds 

 often remaining through summer) east and south coasts Great 

 Britain, but in Orkneys, Shetlands, O. Hebrides and west coast 

 generally, less plentiful, though usually very common Morecambe 



