THE SLAVONIAN GREBE. 455 



sides of nape and sometimes cheeks slightly mottled brown, flanks 

 more lightly marked brownish-black. 



First winter. — Like adult but probably never with rufous mark- 

 ings on feathers behind eyes. The juvenile body-feathers and tail 

 but not wing-feathers or wing-coverts are moulted Sept .-Dec. and 

 sometimes not complete until Feb. First summer. — Birds with 

 brownish crown, chin and cheeks and with short feathers in region 

 of tippet and ill-developed ear -tufts are probably first summer. 



Measurements and structure. — $ wing 134-150 mm., tarsus 

 44-49, bill from feathers 22-27 (15 measured). ? wing 129-145, 

 bill 20-25. Primaries : 1st very small and hidden, 3rd longest-, 

 2nd as long or 1-2 mm. shorter, 4th 2-5 shorter, 5th 11-15 shorter , 

 6th 17-23 shorter ; 2nd to 4th emarginated near tips on outer and 

 inner webs. Bill rather stout, straight, upper mandible at tip 

 curving gently downwards and gonys sharply sloped up. Rest of 

 structure as in Great Crested Grebe. 



Soft parts. — Bill blue -grey, tip whitish, base darker tinged 

 flesh ; legs and feet blue to greenish -grey, toes edged yellowish, 

 outside of tarsus and underside of toes brown-black ; iris rose-pink 

 to orange -pink with silvery inner ring round pupil. 



Characters. — No subspecies. Distinguished from Black-necked 

 Grebe by straight and stouter bill, no white or scarcely any on 

 inner primaries, in summer by chestnut fore-neck, in winter and 

 juvenile by more white on sides of head, white extending to eye 

 and on ear-coverts. Considerably larger than Little Grebe and 

 smaller than Great Crested and Bed -necked. 



Field -characters. — In breeding plumage distinguished by chest- 

 nut neck, black head and tippet, with tuft of yellow feathers pro- 

 jecting like horns from eyes beyond back of head. In winter dark 

 colour of crown does not extend below eye ; pure white of cheeks 

 and throat nearly meet on nape, suggesting a white ring round neck, 

 whereas Black-necked Grebe usually has continuous broad dark line 

 down hind-neck, but critical distinction is stout, straight bill, which 

 in Black-neck is slender and tip-tilted. 



Breeding-habits. — Haunts edges of lochs, and several pairs may be 

 found nesting not far apart. Nest. — Similar to those of other Grebes : 

 a mass of water -weeds and decaying vegetable matter in shallow 

 water with a depression in middle ; wet weeds pulled over eggs 

 on leaving. Eggs. — 4, less commonly 3, 5 or even 6 and 7, white 

 when fresh with soft chalky surface, but rapidly becoming stained 

 by contact with nest. Average of 100 eggs, 44.5x30.7. Max. : 

 49x33.3 and 47.2x33.4. Min. : 39.7x30.1 and 47.1x28.4 mm. 

 Breeding-season. — Occasionally from May 12th onward but generally 

 not till early June. Incubation. — Chiefly by female, male only 

 taking small part. Period 20-24 days (Hantzsch). Probably single 

 brooded. 



Food. — Feathers found in large quantities in stomach together with 

 traces of fish (small freshwater species) ; mollusca (Planorbis, etc.) ; 



