FOOD HABITS OF SHOAL-WATER DUCKS. 41 



Seeds or other parts of five species of true pondweeds (Potamogeton 

 americanus, P. natans, P. Jieteropliyllus, P. zosterifolius, and P. pecti- 

 naius) each were found in from one to three stomachs, and unidentified 

 pondweeds in 44. The gullet and stomach of one wood duck taken 

 at Rush Lake, Michigan, in August, 1908, contained about 350 

 tubers of a species of Potamogeton. The gizzards of three from De- 

 lavan Lake, Wisconsin, were filled with the winter buds of eelgrass 

 pondweed {Potamogeton zosterifolius). Only one wood duck had 

 eaten seeds of bushy pondweed (Najas jiexilis), and the seeds and 

 leaves of widgeon grass (Ruppia maritima) , which form so important 

 an element of food for the gadwall and widgeon, were entirely lacking. 



BEECH FAMILY (FAGACEAE), 6.28 PER CENT. 



Acorns and beech nuts furnish one of the most important items 

 of the wood duck's food, and had the collection of stomachs avail- 

 able been from localities more evenly distributed throughout its 

 range, the percentage of this food very probably would have been 

 much larger. As it was, 3 of the gizzards contained beech nuts and 

 19 contained acorns. Of the latter, 5 species were identified : Red 

 oak (Quercus rubra) from 1 stomach, pin oak (Q. palustris) from 5, 

 water oak (Q. nigra) from 2, black-jack (Q. marylandica) from 2, 

 and valley oak (Q. lobata) from 1, while fragments of acorns found in 

 8 gizzards were not identified. Several of the stomachs containing 

 acorns were crammed with them, the gullet and gizzard of one from 

 Arkansas containing 15 entire acorns of pin oak, with fragments of 

 one or two others. The wood duck's habit of eating acorns is well 

 known, many writers testifying to its fondness for this kind of food. 

 According to the late D. G. Elliot, 15 the wood duck is called " acorn 

 duck" in Louisiana. Wilson and Bonaparte, 16 in 1831, wrote that 

 its food " consists principally of acorns, seeds of the wild oats, and 

 insects." Kumlien and Hollister 17 state that the wood duck "takes 

 to the oak groves about the streams and lakes, and seems to be 

 especially partial to the acorns of the bur oak. These it eats in 

 large quantities." ' 



Without doubt the wood duck's usual method of gathering acorns 

 is by picking them up off the ground or from the water. However, 

 one author, Mr. N". S. Goss, 18 is authority for the statement that, 

 "Their food consists chiefly of insect life, the tender shoots and seeds 

 of aquatic plants, grains, wild grapes and acorns, which they gather 

 as well from the vines and tree tops as upon the ground. . . ." 



is Elliot, D. G. . Wild Fowl of North. America, p. 87, 1898. 



16 WilsoruA., and C. L. Bonaparte, Amer. Ornith., in, p. 203, 1831. 



" Kumlien, L., and N. Hollister, op. cit., Ill, p. 21, 1903. 



™ Goss, N. S., History of the Birds of Kansas, p. 73, 1891. 



