. Bulletin. Histoire naturelle ; l'histoire naturelle. Août, 1959 Anderson : Les habitudes alimentaires de canards migrateurs sauvages 331 mil, fig. 9, au troisième rang parmi les plantes alimentaires indigènes sauvages en pourcentage du total des matières organiques de l'ensemble de la GIZ canard- zards examinés, tableau 38. Bien que sa présence était inégale dans l'Illinois et du Mississippi River Valleys dans les années de l'étude, il s'est classé cinquième dans la se produire- rence index de pourcentage, tableau 37. Au cours de 1939 et 1940, les conditions de niveau d'eau dans certaines régions ont été très favorables pour la croissance et l'ant luxuri- la production de semences de millet lourds (Bellrose, 1941:253). Graines de la

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. Bulletin. Natural history; Natural history. August, 1959 Anderson: Food Habits of Migratory Ducks 331 Wild millet, fig. 9, ranked third among wild native food plants in percentage of the total organic contents of all duck giz- zards examined, table 38. Although its occurrence was spotty in the Illinois and Mississippi river valleys in the years of this study, it ranked fifth in the occur- rence-percentage index, table 37. During 1939 and 1940, water level conditions in some areas were very favorable for luxuri- ant growth and heavy seed production of millets (Bellrose 1941:253). Seeds of the wild millet were found in the gizzards of most ducks and were especially numer- ous in those of pintails, mallards, and green-winged teals. A few pintail gizzards held as many as 1, 000 seeds each, and the craws another 3, 500. Wild millet seeds or other plant parts appeared in 715 gizzards and constituted 6.08 per cent of the total organic contents of the gizzards examined. The heaviest consumption of wild millet occurred in October, when this plant represented 10.76 per cent of the plant foods in the gizzards; the consumption decreased to 3.90 per cent by December, probably as a result of a decline in availability of millet seed and a shift by the mallard and the pintail to a corn diet. Because the seeds remained on the plants until late fall, wild millet proved to be an excellent source of food for ducks; also, the rank stem growth provided pro- tective cover. Longleaf Pondweed Potamogeton nodosus The longleaf pondweed, fig. 10, is con- sidered one of the good duck food plants. Fig. 9.—Wild millet [Echi- iincliloa criisgalli). Known also as barnyard-grass, this moist - soil plant produces seeds that are consumed in large quantities by mallards, pintails, teals, and other ducks. The inset shows wild millet growing on a mud flat from which water has re- ceded. In 1939 and 1940, water levels along the Illi- nois River were especially favorable for growth and seed production of

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