populations also were present in the Eastern 
Bay, Choptank River, and Upper Eastern Shore 
sections. 
Seasonal changes in numbers are shown in 
table 46. During all five surveys, the Chester 
River section contained much higher popula- 
tions than any of the other areas. Fairly 
large numbers were in the Blackwater- 
Nanticoke section, and, during some of the 
surveys, considerable numbers were in the 
Eastern Bay, Upper Eastern Shore, Choptank 
River, Patuxent River, and Coastal sections. 
The central Chester River was the outstanding 
local concentration area for Mallards in the 
Upper Chesapeake region. Other important 
concentration areas were in the upper Black- 
water River area, the upper Chester River, 
upper Eastern Bay, Kent County bay shore, 
and the Patuxent River marsh. 
Food Habits 
The gullet and gizzard food contents of 85 
wild Mallards were examined (tables 47-51), 
A single bird not referred to in the tables 
was collected in the coastal marshes at 
Newport Bay during March. 
Seeds and leaves of widgeongrass and clasp- 
ingleaf pondweed, and corn were the more 
important foods in the complex of estuarine 
bays and agricultural fields (table 47), In the 
river marshes, the more important foods in- 
cluded the seeds of dotted smartweed, soft- 
stem bulrush, common three-square, halberd- 
leaf tearthumb, and arrow-arum (table 48), 
Principal foods in the estuarine bay marshes 
were seeds, leaves, stems, and rootstalks of 
widgeongrass; seeds of Olney three-square 
and twigrush; and corn (chiefly bait) (table 49). 
Principal foods in the river bottomland were 
beech and white-oak mast, seeds of hornbeam, 
and vegetative parts of the alga nitella (table 
50). Principal foods in the draw-down marsh 
impoundments were seeds of common burreed; 
other foods taken in fairly large quantities in 
this habitat included the seeds of weak bulrush, 
buttonbush, sedge (Carez lurida), dotted smart- 
weed, and rice cutgrass (table 51). The single 
bird collected in the coastal marshes had fed 
chiefly on the seeds of Olney three-square and 
common three-square. 
Local Distribution of Hunting Kill 
Information concerning local distribution of 
the hunting kill of Mallards within the Upper 
Chesapeake region was obtained through an 
analysis of the distribution of 244 weighted 
recoveries of wild birds banded outside of 
Maryland and Virginia (table 52), These re- 
coveries were reported during the years 1953- 
57. The number per year ranged from 31 
in 1953 to 80 in 1957. 
36 
Nearly 25% of the kill occurred in the 
Chester River section alone. Approximately 
53% of the kill occurred in the area from the 
Bohemia River to the Choptank River; shallow 
estuarine bays with adjoining agricultural 
fields are common in this area. Eighteen 
percent of the kill was distributed over the 
Blackwater-Nanticoke and Lower Eastern 
Shore sections, areas that contain extensive 
estuarine bay marshes, Approximately 13% of 
the total kill was reported from the salt 
marshes and adjacent impoundments in the 
Coastal section, and 14% of the kill came 
from the various areas west of Chesapeake 
Bay (including the Susquehanna Flats, Patuxent, 
and Potomac River sections), Two percent of 
the kill occurred in the coastal plain interior, 
away from tidewater. The central and lower 
portions of the Chester River were the only 
local areas in which the kill was heavily 
concentrated (22% of total). The kill of Mallards 
as related to their local populations was 
proportionally lowin the Blackwater-Nanticoke 
section. Kill data arranged by months showed 
that 24% of the kill was in November, 52% in 
December, and 24% in January. 
Harvest Areas of Birds Banded in Upper 
Chesapeake Region 
Data concerning harvest areas of wild Mal- 
lards banded inthe Dorchester County marshes 
and in the Chester River-Eastern Bay area 
during the years 1950-58 came from 170 
indirect recoveries (table 53), About half of 
the kill of birds banded in fall and winter, 
and two-fifths of the kill of those banded in 
spring were shot in the mid-Atlantic States. 
A third of the recoveries of fall-banded 
birds, and a fourth of the recoveries of 
winter- and spring-banded birds were from 
Maryland alone. Most of the other recoveries 
were fairly evenly distributed over the eastern 
Great Lakes area, the north-central States, 
east-central Canada, and the Prairie Provinces 
of Canada. 
BLACK DUCK 
Anas rubripes Brewster 
Black Ducks are the only waterfowl that 
are widely distributed over the Upper Chesa- 
peake region throughout the year. They occur 
regularly as summer residents, winter resi- 
dents, and spring and fall transients. 
January inventories for 1953-58 show that 
the wintering population ranged from 49,500 
in 1958 to 229,500 in 1955, averaged 129,700, 
This average figure represents about 19% of 
the continental wintering population and 28% 
of the Atlantic population. The pre-eminence 
of the wintering populations in Maryland, as 
compared with those of other States, is shown 
