FOOD HABITS OF SHOAL-WATER DUCKS. 45 



VINE FAMILY (viTACEAE), 0.82 PER CENT. 



The estimated average percentage, 0.82, of the remains of grapes 

 actually found in the wood duck stomachs, undoubtedly is much 

 less than the true proportion of grapes consumed, for the skins, 

 pulp, and juice are very quickly digested, leaving nothing but the 

 seeds, or much more commonly, fragments of seeds, to show that 

 grapes had been eaten. It is probable that most of these grapes 

 are picked up from the ground in the woods, though some may be 

 taken from the vines. Traces of grapes (always in the form of seeds 

 or seed-fragments) were present in 141 of the wood duck stomachs. 



OLIVE FAMILY (OLEACEAE), 0.72 PER CENT. 



Two wood ducks had eaten seeds of ash (Fraxinus americana and 

 other species). The remainder of the food from this family of plants 

 consisted of the seeds of swamp privet (Adelia acuminata), which 

 were present in 31 stomachs. This is a favorite food for wild ducks 

 in some southern localities, according to the testimony of numerous 

 hunters. "Wood ducks in particular are said to feed extensively 

 upon its seeds. Weeks before other species of ducks arrive these 

 birds are abundant in the country where swamp privet grows and 

 are said to consume most of the crop of seeds, leaving little for other 

 ducks." 20 The plant is a shrub or small tree, and the seed, which 

 has a fibrous, ridged coat, is inclosed in a watery blue berry from 

 one-half to three-fourths of an inch in length. These berries ripen 

 in May and June and fall into the water; many of them are picked 

 up from the bottom by the ducks later in the season. The swamp 

 privet grows in the same kind of localities as the water elm, and its 

 seeds usually were found in company with the seeds of that plant 

 in the stomachs of wood ducks. One stomach and distended crop 

 were found which held 157 of these large seeds, with remains of 

 several more. A sprig of swamp privet was sent to the Biological 

 Survey by C. G. Wright, of Dallas, Tex., with the statement that it 

 was grown from seed taken from a wood duck's gizzard, which was 

 absolutely full of them. 



MISCELLANEOUS VEGETABLE FOOD, 9.4 PER CENT. 



A great number of smaller items, each of which amounted to less 

 than 1 per cent, made up the remainder of the wood duck's vegetable 

 food. In some localities the ducks had fed upon the tubers and 

 seeds of arrowheads (Sagittaria latifolia and other species) ; and three 

 from Caruthersville, Mo., had stuffed themselves with the stems, 

 leaves, and rootstocks of a crowfoot (Ranunculus sp.). Three taken 

 in Okefenokee Swamp, Georgia, in December, 1916, had been feeding 

 upon the crimson rootstocks of red-root or paint-root {Gyrotheca 



20McAtee, W. L., Eleven Important Wild-duck Foods, Bull. No. 205, U. S. Dept. of Agr., pp. 12-13, 1915. 



