. Bulletin. Natural history; Natural history. August, 1959 Anderson: Food Habits of INIigratory Ducks 337. Fig. 17.—Duck-potato [Sagittaria lafifolia), known also as arrowhead, wapato, or boot- jack. Ducks value it more for its seed than for its tubers. total organic contents of the gizzards col- lected for examination, table 38. The plant apparently increased in duck food value as the fall season waned. In Octo- ber, it represented less than 1 per cent of the plant contents of gizzards, but 3 per cent by December. This plant may be considered a fair duck food throughout the fall, increasing i
. Bulletin. Natural history; Natural history. August, 1959 Anderson: Food Habits of INIigratory Ducks 337. Fig. 17.—Duck-potato [Sagittaria lafifolia), known also as arrowhead, wapato, or boot- jack. Ducks value it more for its seed than for its tubers. total organic contents of the gizzards col- lected for examination, table 38. The plant apparently increased in duck food value as the fall season waned. In Octo- ber, it represented less than 1 per cent of the plant contents of gizzards, but 3 per cent by December. This plant may be considered a fair duck food throughout the fall, increasing in importance as the season advances. River-Bulrush Scirpus fluviatilis River-bulrush seeds occurred in about one-tenth of the duck gizzards collected in 1938-1940 from areas along the Illi- nois and Mississippi rivers, table 38. The total quantity of river-bulrush seeds was only per cent of all the organic food. The number of gizzards in which river- bulrush seeds were found (510) is con- sidered large in view of the fact that seed production of this plant is poor in Illinois (Bellrose & Anderson 1943:430). Evi- dently the seeds are very palatable. Teal Grass Eragrostis hypnoides Teal grass was found to be another moist-soil plant that ranked among the important sources of duck food in the pe- riod of this study, table 37. Under cer- tain conditions, when water levels were sufficiently high to flood the plants grow- ing along ditchbanks and mud flats, it ranked much higher than when conditions were less favorable. It appeared among the important native foods because of large numbers of seeds consumed by a relatively small number of ducks. The green-winged teal, blue-winged teal, and pintail fed more upon this plant than did other spe- cies of ducks. Seeds of teal grass, found in 114 giz- zards, constituted per cent of the total organic contents, table 38. After Novem- ber 15, utilization of this plant rapidly de- creased. The drop was due partly to ice fringes t
Size: 1416px × 1765px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., booka, bookcentury1900, bookdecade1910, booksubjectnaturalhistory
