for the scattered pairs of breeding Wood Ducks 
and are also of major importance for migrant 
birds. During the fall flight, Wood Ducks often 
concentrate in bottomland areas that contain 
an abundant food supply, especially mast of 
beech and oaks. Locally, considerable numbers 
of breeding and migrant Wood Ducks also 
occur along the wooded margins or marsh 
fringes of the interior impoundments; they 
seem to have some preference for impound- 
ments that contain stands of spatterdock. 
Small numbers may be found in fresh es- 
tuarine bay marshes, especially in areas 
where associations of narrowleaf cattail and 
white waterlily are predominant. 
In spring and fall, and during the post- 
breeding period inlate summer, comparatively 
large numbers of Wood Ducks also occur in 
the various estuarine river marshes through- 
out the region. In these marshes, the greatest 
numbers of Wood Ducks usually are in the 
fresh or slightly - brackish portions, particu- 
larly in areas where arrow-arum is common, 
Wood Duck nests ordinarily are in cavities 
of large deciduous trees, usually more than 
10 feet from the ground. Nest cavities are in 
dead snags as well as in living trees, and 
may include abandoned tree dens of raccoons 
and gray squirrels, and old Pileated Wood- 
pecker holes, The erection of nest boxes for 
Wood Ducks has increased local breeding 
populations. Methods for construction and 
location of predator-proof nest boxes are 
discussed by Webster (1958). 
Biogeographic Sections 
During the migration periods, Wood Ducks 
usually are in small flocks of from 4 to 12 
birds. Larger numbers occasionally are re- 
corded on favorite feeding grounds or on 
roosting areas. Highest 1-day ground or boat 
counts include the following: 600 at Patuxent 
Wildlife Research Center, Prince Georges 
County, on October 19, 1959; 206 in Patuxent 
estuarine river marsh on September 24, 1947; 
145 in Patuxent estuarine river marshon March 
17, 1958; 90 on Nanticoke estuarine river marsh 
on November 3, 1955. Repeated counts of Wood 
Ducks in the Patuxent estuarine river marsh 
area indicate that the total Patuxent marsh 
population usually ranges between 300 and 500 
birds during the migration peak in fall. Other 
important concentrations 
Ducks are in the upper tidewater areas of the 
following rivers: Pocomoke, Wicomico (in 
Wicomico County), Nanticoke, Chicamacomico, 
Transquaking, Blackwater, Choptank, Chester, 
Sassafras, Elk, Bush, and Gunpowder. Local 
concentrations also are found in a few areas 
along the Potomac River, including Allen's 
Fresh, Port Tobacco River, Nanjemoy Creek, 
Mattawoman Creek, and Piscataway Creek, 
In the coastal plain interior, concentrations of 
birds may be found on some of the mill ponds 
of migrant Wood . 
47 
in the eastern shore sections, onthe numerous 
impoundments at the Patuxent Wildlife Re- 
search Center, and in the wooded bottomlands 
along the larger streams, including the 
Patuxent, Nanticoke, and Pocomoke Rivers, 
and Zekiah Swamp. 
Food Habits 
The gullet and gizzard food contents of 79 
Wood Ducks were examined. Data for 77 of 
these are shown in tables 91-92. In addition 
to these, one bird was collected on an interior 
impoundment at Remington Farms in Kent 
County on November 18, and another was 
taken on the Susquehanna Flats on March 24, 
The most important foods of Wood Ducks 
from the river bottomlands (table 91) were 
beech nuts and acorns of various oaks, par- 
ticularly white oak and pin oak. Other foods 
commonly taken by birds in the bottomlands 
included the fruits and seeds of a variety 
of plants, such as halberdleaftearthumb, horn- 
beam, and blackgum; and the leaves of sub- 
merged plants, particularly ribbonleaf pond- 
weed and Nuttall waterweed. Yearly and 
seasonal variation in the selection of par- 
ticular food items seemed to be correlated 
with changes in the availability of the foods. 
The seeds of arrow-arum were the pre- 
dominant food taken by Wood Ducks in the 
estuarine river marshes (table 92), A con- 
siderable variety of seeds of other marsh 
plants also were eaten. There was some 
preference for the larger seeds, including 
giant burreed and halberdleaf tearthumb., 
The Wood Duck collected at Remington 
Farms had fed chiefly on oak acorns and 
seeds of dotted smartweed. The Wood Duck 
collected on the Susquehanna Flats on March 
24 had fed chiefly on winter buds of wildcelery. 
The occurrence of foods in 26 samples of 
droppings from the Patuxent Wildlife Research 
Center (examined by C. G. Webster and F, M. 
Uhler) collected during spring and early sum- 
mer (March-June) was: oak acorns - 27%; 
seeds of dotted smartweed - 15%; redroot 
cyperus - 15%; halberdleaf tearthumb - 12%; 
corn ~ 8%; grape - 4%; swamp smartweed - 
4%; spatterdock - 4%; greenbrier - 4%; sedge 
(Carez canescens) - 4%; and insect fragments - 
11%. 
Local Distribution of Hunting Kill 
Information concerning local distribution of 
the hunting kill of Wood Ducks within the Upper 
Chesapeake region was obtained through an 
analysis of the distribution of 29 weighted 
recoveries of birds banded outside of Mary- 
land and Virginia (table 93), These recoveries 
were reported during the years 1951-56, The 
number per year ranged from three in 1955 
and 1956 to eight in 1954, 
