PRELIMINARY CLASSIFIED NOTES 439 



(cf. Ticehurst, B. of Kent, 1909, p. 537 ; and Saunders, III. Man. British Birds, 

 2nd ed., 1899, p. 713). In Ireland the blackthroated-diver has only been recorded 

 some twenty-five times, including, however, both an adult and an immature 

 example obtained late in July 1906 (cf. Ussher and Warren, B. of Ireland, 1900, 

 p. 373; and Ussher, quoted by Witherby and Ticehurst, British Birds, vol. ii. 

 p. 421). [A. L. T.] 



4. Nest and Eggs. In Scotland the favoured nesting-haunts are islets on 

 mountain lochs. As a rule it is placed close to the water's edge, less frequently a few 

 yards inland, and in most cases there is no real nest, the vegetation being merely 

 pressed down by the weight of the incubating bird, and withered by the heat of its 

 body. Sometimes a few fragments of heather, grass, or rushes may be found roughly 

 arranged round the eggs. (PI. LXXVII.) Exceptionally, however, in Norway this 

 diver has been recorded as building a substantial nest for itself of weeds, grasses, 

 moss, etc., but the share of the sexes in building is apparently not mentioned. 

 The eggs are normally 2, sometimes 1 only, though this is exceptional, but three 

 young have been seen together in Norway. The eggs are as a rule much larger 

 than those of the redthroated-diver, and at times rival those of the great-northern 

 in length, though narrower. The colour varies from deep brown to brownish 

 olivaceous and light olive-green, with similar markings to those on the eggs of the 

 great northern-diver. Some eggs are extremely elongated in shape. (PL W.) 

 Average size of 78 eggs, 3*33x2-04 in. [84 '6x51 '8 mm.]. Incubation is stated 

 in Tiedemann's table to last 28 days, but recent observations on this point are 

 altogether lacking. 1 The male takes part in incubation, sharing the duty in turn 

 with the female (Graf Zedlitz). The breeding season in Scotland begins early in 

 May, but is more general after the middle of the month. As two or even three 

 clutches may be laid by a pair which has been robbed, eggs may be found 

 throughout May and June. In Norway near the coast eggs may be found in the 

 first week of May, but often not till a month or five weeks later on the high fjeld, 

 and in the high north eggs may be found in July. Only one brood is reared in 

 the season. [F. c. R. J.] 



5. Food. To a great extent, though not entirely, fish. In the breeding 

 season probably chiefly trout, at times also salmon fry; in Norway chiefly Salmo* 

 eriox. In winter, however, one was found to contain eight herrings, and Collett 

 records Palcemon squilla and various species of Odbius. One specimen contained 

 Algae (tang), sand, small fragments of wood, and vegetable matter, but no animal 



1 Graf Zedlitz apparently records the period on Tiedemann's authority. 



