246 THE DIVING DUCKS 



3. Migration. A resident, and also a winter visitor and a bird of passage 

 from the Continent. The winter visitors arrive between 15th September and 

 13th October, while the seasons of passage are from 29th October to 27th November 

 and from 24th April to 10th May (cf. Clarke, Studies in Bird Migration, 1912, vol. i. 

 pp. 136, 160). Ireland receives most of its winter birds in December, while April 

 is the month of departure (cf. Ussher and Warren, B. of Ireland, 1900, p. 207). 

 In North Wales the species is not a very common whiter visitor, and in Kent it is 

 only numerous in hard seasons (cf . Forrest, Fauna of N. Wales, 1907, p. 286 ; and 

 Ticehurst, B. of Kent, 1909, p. 384). Gregarious as a migrant, and visits both 

 coastal and inland waters. [A. L. T.] 



4. Nest and Eggs. The usual nesting-place is a hollow among rushes, 

 coarse grass, occasionally heather, or under rhododendron and other bushes, 

 generally on islands or the shores of lakes, and as a rule at no great distance from 

 the water. The hollow is lined by the duck with a few grasses or dead leaves, 

 which become mixed with the down, which is dull, dusty brown with indistinct 

 light centres. (PI. Lxvin.) The small greyish white nest feathers are figured by 

 Noble (Brit. Birds, ii. pi. 2, fig. 11), and see PI. U. This duck is of a social disposi- 

 tion, and may be said to nest in colonies as a rule. The eggs vary in number 

 from 8 or 9 to 12, but nests with from 14 to 16 eggs are not infrequently met 

 with. Larger numbers such as 18, 21, and 28 are due to more than one duck 

 laying in a nest. In colour they are a duty olivaceous brown shading into 

 greenish olivaceous or brownish yellow, while the shape is somewhat characteristic, 

 many eggs being elongated, sometimes approaching those of the sand-grouse in 

 shape. The shell is rather coarse and has little gloss. Average size of 150 

 eggs, 2-32x1-61 in. [59-0x40-9 mm.]. (PI. S.) Incubation is performed by the 

 duck alone, and the period seems to vary somewhat. Noble estimates it as 23 

 days (in incubator), Heinroth at 25 to 26 days, W. Evans 25 to 28 days, while 

 a writer in the Field finds that his results for three years vary from 23 to 28 

 days. The breeding season is late, full clutches being rarely found before mid- 

 May and often not till the end of the month or early in June, while the normal 

 date for Scotland is about the first week of June. Only one brood is reared in the 

 season. [F. c. B. J.] 



5. Food. Both animal and vegetable food is eaten by this duck. On 

 inland waters it subsists to a great extent on the buds, seeds, roots, bulbs, and 

 leaves of various aquatic plants obtained by diving. Jackel mentions Polygonum 

 amphibium, persicaria, and lapathifolium, Rumex and Potamogeton. Newstead found 



