DIVERS 93 
ceding species. Lobed toes (see Fig. 109, No. 183). Tail almost 
absent. Upper-parts dark brown. Under-parts whitish, except 
the chestnut throat and sides of the neck, and the dusky flanks 
and the black chin. The white on the secondaries is limited to 
the inner webs. Legs dull green. Beak horn colour, with 
yellowish-green at the gape. Female smaller. After the 
autumn moult the chin and throat are white, and the chest- 
nut of the sides of the neck fades to buff. Young much like 
the adult in winter plumage. 
Nest. A mass of aquatic plants placed usually among reeds 
or other water-plants in or by lakes, ponds, and sluggish 
rivers, Also in the open in shallow water, or near the bank 
under overhanging branches. Either floating and attached to 
surrounding elias. or built up from the bottom. Not nor- 
mally floating free. Eggs usually covered when bird not on. 
Eggs. Usually 4-6. Bluish-white, but rapidly stained 
varying shades of dirty browns or reds. Av. size, 1°48 x 1°02 
in. Laying usually begins April. Broods probably two. 
XII. ORDER: COLYMBIFORMES. (2) SUBORDER: 
COLYMBI 
Family : Colymbide—Divers 
185. Great northern-diver [Gavia immer (Briinnich) ; 
Colymbus glacialis Linnzus}. Winter visitor and bird of 
passage to our coasts and inland waters, chiefly northern. 
Occurs also in summer, 
Bird. Length 31 in. ; male the larger. Recognised by the 
black, green, and purple glossed head and neck, broken on the 
throat and neck by two white bands, marked with close set, 
parallel, dark downward streaks, which 
are continued below the green on the 
white of the lower neck. Mantle glossy 
black, with conspicuous cross bands of 
white spots. Under-parts white. Beak 
black, strong and pointed. Legs mostly 
Sosaedanage Wing quills and tail 
ark-brown, the latter short and rounded. 
After the autumn moult the upper-parts, 
including the head and nape, are darkish brown with paler 
margins to the feathers. All under-parts, including throat 
and breast, white with streaks on the neck. The much rarer 
blackthroated-diver, though not unlike the present species, may 
be distinguished at all ages and seasons by the smaller size (27 
in.) and the shorter, more slender bill ; and in breeding plumage 
by the ash-grey crown and nape and the purplish-black throat. 
