BLUE GOOSE 
Chen caerulescens (Linnaeus) 
Small flocks or scattered birds occasionally 
occur along the eastern shore of Chesapeake 
Bay. There are a few records of their pres- 
ence in the western shore areas and along the 
coast. These small groups or individuals usu- 
ally are associated with small numbers of 
Snow Geese. Dates of records of Blue Geese 
in the Upper Chesapeake region extend from 
mid-October to mid-May. 
Habitats 
These geese have been observed in open 
estuarine waters, in artificial impoundments, 
and in agricultural fields nearby. A few 
occasionally are seen in the large estuarine 
bay marshes of Dorchester and Somerset Coun- 
ties, and in the coastal salt marshes of Wor- 
cester County. 
Food Habits 
The gullet and gizzard food contents of one 
Blue Goose were composed entirely of leaf 
fragments of saltmarsh cordgrass. The bird 
was collected in the brackish estuarine bay 
marshes of Dorchester County on November 
25, 1955. 
MALLARD 
Anas platyrhynchos Linnaeus 
The mallard is a locally common transient 
during spring and fall, and a winter resident, 
throughout most of the Upper Chesapeake 
region. A few scattered pairs of birds breed 
in the region during the summer months. The 
breeding birds probably are derived from 
introduced game-farm stock. January inven- 
tories for 1953-58 show that the wintering 
population ranged from 16,300 in 1953 to 
150,900 in 1956, averaged approximately 
68,700. This average figure represents less 
than 1% of the continental population and about 
24% of the Atlantic population. The fall migra- 
tion usually is during the period of September 
10-20 to December 15-25, with the peak 
between October 25 and December 5. The 
normal spring migration extends from Feb- 
ruary 5-15 to May 1-10, with the peak between 
Feburary 20 and March 20, 
Habitats 
Shallow brackish estuarine bays with adja- 
cent extensive agricultural areas apparently 
are the optimum combination of habitats for 
35 
Mallards in the Upper Chesapeake region. 
These conditions are widespread in the Chester 
River section, where the greatest numbers of 
birds occur. Large numbers also are present 
in the complex of brackish estuarine bays and 
agricultural fields of the Eastern Bay and Chop- 
tank River sections. Mallards also are nu- 
merous in the complex of fresh estuarine 
bays and agricultural fields of the Upper 
Eastern Shore section. Mallards in these 
areas feed chiefly in the larger grain fields. 
They roost in the shallow open estuarine 
waters and also feed there to a limited ex- 
tent. Many Mallards roost on the artificial 
ponds that are scattered through the farm- 
lands. 
Mallards usually are locally common in the 
scattered estuarine river marshes throughout 
the region, and in the fresh estuarine bay 
marshes of the Blackwater-Nanticoke section. 
Fair numbers occasionally are present in the 
brackish estuarine bay marshes in the Black- 
water-Nanticoke section and in the various 
river swamps, flood-plain forests, and draw- 
down marsh impoundments that are scattered 
throughout the coastal plaininterior. Relatively 
small numbers are ordinarily present in the 
coastal salt marshes or in the salt estuarine 
bay marshes of the Lower Eastern Shore sec- 
tion. The birds generally feed and roost in 
these habitats, although locally they may feed 
in adjacent grain fields. When Mallards are 
unduly disturbed by excessive hunting or other 
human activities, they sometimes shift to 
some of the larger estuarine bays nearby. 
The ecological distribution of Mallard popu- 
lations during the 1958-59 season is shown in 
table 44. From 50% to 86% of the total 
population was found in the complex of shallow 
estuarine bays and agricultural fields in the 
Chester River, Upper Eastern Shore, Eastern 
Bay, and Choptank River sections. Fairly 
large numbers also were counted in the es- 
tuarine river marshes that are scattered 
through the region, and in the fresh estuarine 
bay marshes of the Blackwater-Nanticoke 
section. j 
Two nests were found of Mallards believed 
to be wild birds. One nest, containing 12 eggs, 
was found on April 22, 1944, at the Patuxent 
Wildlife Research Center; the nest was ona 
small brushy hummock about 50 feet from 
shore in one of the larger impoundments. The 
other nest, also containing 12 eggs, was 
found June 26, 1957, on one of the small 
islands in Sinepuxent Bay; it was in a patch of 
saltmeadow cordgrass under a groundselbush. 
Biogeographic Sections 
The average distribution of Mallards during 
the January inventories of 1955-58 is shownin 
table 45, The Blackwater-Nanticoke and Ches- 
ter River sections contained about two-thirds 
of the total Upper Chesapeake population, Fair 
