LIFE HISTORIES OF NORTH AMERICAN WILD FOWL. 133 



Eggs. — Macgillivray (1852) describes the eggs as follows: 



The eggs, from 8 to 12, are of an oval form, rather pointed at one end, smooth 

 glossy, and thin shelled, of a white color, slightly tinged with reddish, their length 

 from 2{l inches to 2y\ inches and their breadth an inch and ten or eleven twelfths. 

 The male continues in the neigliborhood of the nest during incubation, and is said 

 occasionally to take the place of the female. 



Witherby's Handbook (1920) gives the number of eggs as normally 

 8 to 15, but as many as 16, 20, 28, and even 32 have been recorded. 

 The measurements of 100 eggs, therein recorded, average 65.7 by 47.3 

 millimeters; the eggs showing the four extreme measure 71 by 48.8, 

 69 by 50, 60 by 44, and 62.8 by 43.3 millimeters. 



Young. — The period of incubation is given by various writers as 

 from 24 to 30 days or about 4 weeks. It is said to be performed 

 mainly by the female, but apparently partially by the male as well. 

 Bewick (1847) writes: 



During this time the male, who is very attentive to his charge, keeps watch in 

 the daytime on some adjoining hillock, where he can see all around him, and which 

 he quits only, when impelled by hunger, to procure subsistence. The female also 

 leaves the nest for the sime purpose in the mornings and evenings, at which times 

 the male takes his turn and supplies her place. As soon as the young are hatched, 

 or are able to waddle along, they are conducted, and sometimes carried in the bill, 

 by the parents to the full tide, upr>n which they launch without fear, and are not 

 seen afterwards out of tide mark until they are well able to fly; lulled by the roar- 

 ings of the flood, they find themselves at home amidst an ample store of their natural 

 food, which consists of sand lioppers, sea worms, etc., or small shellfish, and the 

 innumerable shoals of the little fry which have not yet ventured out into the great 

 deep but are left on the beach or tossed to the surface of the water by the restless 

 surge. 



If this family, in their progress from the nest to the sea happen to be interrupted 

 by any person, the young ones, it is said, seek the first shelter, and squat close down, 

 and the parent birds fly off, then commences that truly curious scene, dictated by 

 an instinct analogous to reason, the same as in the wild duck and the partridge; the 

 tender mother drops, at no great distance from her helpless brood, trails herself along 

 the ground, flaps it with her wings, and appears to struggle as if she were wounded, in 

 order to attract attention, and tempt a pursuit after her. Should these wily schemes, 

 in which she is also aided by her mate, succeed, they both return when the danger 

 is over, to their terrified motionless little offspring, to renew the tender offices of 

 cherishing and protecting them. 



Food. — Mr. John Cordeaux (1898) says of its feeding habits: 



As far as my own observation goes, on the Lincolnshire coast, the sheld duck ap- 

 pears to live exclusively on various mollusca and crustaceans; the stomach is remark- 

 able for its very thick and strong muscular coat, capable of digesting any tough 

 morsel. In the stomach of one I found some sand and many small shells of the genus 

 Buccinum. The late Mr. Thompson opened the stomachs of 10 shot in Belfast Bay 

 and took from one of them 9,000 specimens of Skeyiea depressa and Montucuta purpurea, 

 and about 11,000 others, making a total of 20,000 shells in the crop and stomach of a 

 sinqle sheld duel". Mr. St. John says: "Its food appears to consist almost wholly of 

 small shellfish, and more especially of cockles, which it swallows whole. It extracts 



