220 TADORNA TADORNA 



nests are robbed each day, the duck will continue to lay, even up to twenty or 

 thirty eggs. The normal clutch, however, is seven to twelve, though as many as 

 sixteen have been noted. The down is also utilized and is said to be nearly as good as 

 that of the Eider. In color the eggs are yellowish white, with the slightest greenish 

 sheen. They are very fine in texture, and measure 64.7 to 68.7 mm. in length by 

 48.1 to 49.1 mm. in breadth. On the breeding colonies of Sylt, the reader is referred 

 to the excellent accounts of Naumann (1896-1905), Mobius, Zool. Garten, vol. 11, 

 p. 133, 1870, and Hagendefeldt, Zeitschr. f. Ornith., vol. 30, p. 121, 1906. 



In wild colonies the male stays in the vicinity of the nest, and is ready to join the 

 female when she leaves the burrow to feed. At times he enters the hole, but there is 

 no adequate evidence that he takes part in the incubation, as stated by Bewick 

 (1821), Stevenson and Southwell (1890), and others. The incubation period is 

 twenty-eight to thirty days in length. There is a difference of opinion as to whether 

 the female leaves any tracks on entering the burrow. Some writers have maintained 

 that the female dashes in on the wing without leaving any tracks (Cordeaux, 1896), 

 but most others insist that the nest may easily be found by the prints of the feet, 

 though these are soon covered by drifting sand. 



When the young are hatched, they are conducted by both parent birds to the 

 water, which in some cases may be at a distance, thus entailing a long walk through 

 dangerous neighborhoods. There are the usual stories of the young being carried 

 down from elevated cliffs, etc., in the bill, or on the back of the female. Payne- 

 Gallwey (1882) claims to have seen ten to twelve ducklings carried down on 

 the mother's back. Such stories have been repeated in many ornithologies, but 

 these occurrences are at best very exceptional. Bodinus (1862) proved to his own 

 satisfaction that the young are allowed to drop from elevated nesting sites. 



During the walks to the water many of the young are captured by fishermen, 

 who attempt to raise them in captivity. Cordeaux (1896) noticed a brood of ten 

 young with the female leading and the male bringing up the rear some six yards be- 

 hind and guarding the flock. This brood walked about one-half mile in half an hour. 

 The young are not always taken directly to the sea, and the early growing period 

 may frequently be spent on some small body of fresh water near the nest, where 

 grasses and rushes offer a place for concealing the young in case of danger. It is not 

 known exactly how long the male remains with his family, but he probably does so 

 for a short time only, as he moults in late June or in early July. The female stays 

 with her young until they are active on the wing, her moult taking place at least 

 a month later. In the British Isles home-bred birds leave by mid-October, and there 

 is a period of five or six weeks between this time and the arrival of more northern or 

 eastern breeders that winter in the islands. Many non-breeding birds spend the 

 summer months on the coasts (Cordeaux, 1896; and others). Before migrating the 

 old and young birds assemble in separate flocks, the former on the sea-coast, the 



