FOOD HABITS OF SHOAL-WATER DUCKS. 4] 
Seeds or other parts of five species of true pondweeds (Potamogeton 
americanus, P. natans, P. heterophyllus, P. zosterifolius, and P. pecti- 
natus) 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 jflexilis), 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, the wood duck is called ‘acorn 
duck” in Louisiana. Wilson and Bonaparte,’ in 1831, wrote that 
its food “consists principally of acorns, seeds of the wild oats, and 
insects.””. Kumlien and Hollister” state that the wood duck ‘takes 
to the oak groves about the streams and lakes, and seems to be 
especially pe 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, 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 ee 
as well from the vines and tree tops as upon the ground. 
16 Elliot, D. G., Wild Fowl] of North America, p. 87, 1898. 
16 Wilson, A., and C. L. Bonaparte, Amer. Ornith., III, p. 203, 1831. 
Vv Kumlien, L., and N. Hollister, op. cit., III, p. 21, 1903. 
18 Goss, N.S., History of the Birds of Kansas, p. 73, 1891. 
