LIFE HISTORIES OF NORTH AMERICAN WILD FOWL 55 



ends and lighter colors of the tail and under parts. The under parts are not 

 nearly so broadly speckled as the adult, and there is a greater area of white. 

 The flanks are grayer, and have a sandy tinge. Also the white spaces about 

 the eye are always more heavily edged with slaty-brown. 



I should add to this that in the young female the head is usually 

 duller brown and the feathers of the back show more light edgings. 

 Of the eclipse plumage Mr. Millais (1913) says: 



The whole plumage of the adult male in eclipse is a uniform dark slate gray, 

 the head and neck being somewhat darker, as well as the rump, under and 

 upper tail coverts, which are almost black ; the single white ear covert spot is 

 retained, and the white space in front of the eye is dull white, both these parts 

 being edged with black ; long scapulars, lower neck, upper and lower flanks, 

 sooty brown; about the end of August the wings and tail are shed (as usual 

 only once). Like all the diving ducks, the male harlequin is practically in a 

 state of molt from July 1 until it reaches the full winter plumage early in 

 October. 



Food. — Most of the harlequin duck's food is obtained by diving, 

 but much of it is picked up along the shores or about the rocky 

 ledges. On the inland streams where it breeds it consists largely 

 of water insects and their larvae, among which the caddis fly is 

 prominent; it also includes fish spawn, small fishes, small frogs, tad- 

 poles, small fresh-water crustaceans and mollusks, and some aquatic 

 plants. On the seacoast it feeds on similar kinds of marine animal 

 life which it picks up on the kelp-covered rocks at low tide or obtains 

 by diving in the surf along the shore or over the ledges; it ap- 

 jDarently does not often dive for its food in deep water. The com- 

 mon black mussel {Mytelus edulis) is one of its main food supplies; 

 these mollusks grow in immense beds on shallow ledges and are 

 easily obtained; occasionally a large mussel has been known to trap 

 the duck and cause its death by drowning. Small crustaceans, such 

 as sand fleas and small gasteropods, are also picked up. 



R. P. Whitfield (1894) gives the following account of the con- 

 tents of a bird's stomach, taken on Long Island : 



In December, 1893, Mr. William Dutcher brought to me the stomach contents 

 of a harlequin duck {Histrionicusf histrionicus) shot at Montauk Point, 

 Long Island, about the 3d of the month. An examination of the material 

 showed what an industrious collector the bird must have been, for it had in 

 its crop remains of no less than three individuals of the small mud crab of 

 our coast, Panopeus depressa Smith, one carapace being almost entire ; besides 

 remains of some other forms of Crustaceans. Of the little shell Columbella 

 lunata {Astyris lunata of the Fish Commission Reports), there were no less 

 than 39 individuals represented, besides several small Littorinas. This shell 

 is seldom more than one-sixth of an inch long, and is usually quite rare on 

 our shores. It could only have been obtained in such numbers by a sort 

 of sifting of the bottom mud of the bays by the duck, and indicates how 

 carefully the process had been carried on in order to obtain so small an article 

 of food. 



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