LIFE HISTORIES OF NORTH AMERICAN WILD FOWL. 83 



As computed from the contents of 3G2 stomachs collected during the six montlis 

 from September to March, 97.85 per cent of the food of the gadwall consists of vege- 

 table matter. Tliis is made up as follows: I'ondweeds, 42. S3 per cent; sedges, 19.91; 

 algae, 10.41; toon tail, 7.82; grasses, 7.59; arrowheads, 3.25; rice and other cultivated 

 grain, 1.31; duckweeds, 0.61; smartweeds, 0.59: wild celery and water weed, 0.5:!; 

 water lilies, 0.52: madder family, 0.37; and miscellaneous, 2.(il per cent. 



Considerably more animal food is taken in summer than in winter, owing, of 

 course, to the fact that more is available at that time oi the year. The percentage 

 of animal food for the summer months is higlier also because there are included in 

 the averages analyses of numerous stomach contents of ducklings, which feed to a 

 great exteJit upon insects. All of the 11 stomachs collected during the month of 

 July (9 from North Dakota and 2 from Utah) were of young ducklings. A computa- 

 tion of the a\ erage contents of this series produced the following results: Water bugs, 

 56.18 per cent; beetles, 7.09; flies and their larvae, 2; nymphs of dragon flies and 

 damsel flies, 0.27; other insects, 2; total animal food, 07.54 per cent; pondweeds, 

 12.55 per cent; grasses, 5.09; sedges, 2; water milfoils, 0.55; smartweeds, 0.09; mis- 

 cellaneous, 12.18; total vegetable food, 32.40 per cent. 



The animal food of adults includes small fishes, crustaceans, tad- 

 poles, leeches, small mollusks, water beetles and other insects, larvae, 

 and worms. 



BeJiavior.'-rhe gadwall can walk well on land,, where it forages for 

 oak mast in the woods and for grain in the o]>en fields, often a long 

 distance from water. It takes flight readily from either land or water, 

 springing into the air and flying swiftly away in a straight line. 

 When migrating, it flies in small flocks of about a dozen birds; in 

 appearance and manner of flight it greatly resembles the baldpato, 

 but the male can usually bo distinguished from the latter by the 

 white speculum and the brown ^ving coverts; a similar difference 

 exists between the females, but only to a slight degree; practiced 

 gurmers claim to recognize other field marks, but they have proven 

 too subtle for my eyes, and I have frequently mistaken one species 

 for the other. The gadwall ought not to be mistaken for any other 

 species, except the baldpate or the European widgeon, but it fre- 

 quently is confused, by ignorant gunners, with the young males and 

 females of the pintail, though its flight and general appearance are 

 entirely different; the name "gray duck" has been applied to both 

 the gadwall and the pintail, which has led to much confusion of 

 records and to erroneous impressions as to the former abundance 

 of the gadwall in New England, where, I believe, it has always been 

 a rare bird. 



Doctor Wetmore (1920) describes the notes of the gadwall as fol- 

 lows: 



The call note of the female is a loud quack that is similar to that of the female 

 mallard but is pitched slightly higher and is not quite so loud and raucous. Consider- 

 able experience is required, however, to distinguish with certainty the calls of the two 

 birds. Tlie male has a loud call like kach hack, a deep reedlike note resembling the 

 syllable vhurk, and a shrill whistled call. 



