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 plants, 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 '48x1*02 

 in. Laying usually begins April. Broods probably two. 



XII. ORDER : COLYMBIFORMES. (2) SUBORDER : 

 COLYMBI 



Family : Colymbidce Divers 



185. Great northern-diver [Gavia immer (Briinmch) ; 

 Colymbus glacialis Linnseus]. 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 

 ape 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 

 greenish-black. Wing quills and tail 

 dark-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. 



