Fall migration usually is during the period 
from October 20-30 to December 15-25, with 
the peak between November 15 and December 
10, The normal spring migration extends from 
February 15-25 to May 5-15, with the peak 
between March 5 and April 25. 
Habitats 
Most Common Mergansers are fairly evenly 
distributed over the fresh estuarine bays of 
the Upper Potomac, Upper Western Shore, 
Susquehanna Flats, and Upper Eastern Shore 
sections. Many also inhabit the fresh estuarine 
bay marshes of the Blackwater-Nanticoke sec- 
tion, and a few range into slightly brackish 
estuarine bays and estuarine river marshes 
throughout the region. Flocks often visit many 
of the larger interior impoundments during 
spring and fall and during open winters. 
Food Habits 
The gullet and gizzard food contents of 2 
Common Mergansers collected on fresh es- 
tuarine bays of the Potomac River during 
December and January were examined. These 
birds had fed chiefly on pumpkinseed sunfish 
(Lepomis gibbosus) and yellow perch (Perca fia- 
vescens). 
RED-BREASTED MERGANSER 
Mergus serrator Linnaeus 
Red-breasted Mergansers are characteris- 
tic inhabitants of the more saline tidewaters, 
in contrast to the Common Mergansers, which 
occupy the fresh tidewaters. Transient Red- 
breasted Mergansers are widespread and lo- 
cally common in the Upper Chesapeake region, 
and many remain during the winter. Highlocal 
counts of Red-breasted Mergansers are as 
follows: 5,000 on Sinepuxent Bay on November 
2, 1945; 153 in the Ocean City Inlet area on 
April 6, 1946; 77 in the St. Michaels area, 
Eastern Bay, on December 29, 1953; 71 on the 
Northeast River, Cecil County, on March 3l, 
1955; and 54 on the Patuxent River on January 
12, 1955. The fall migration usually is during 
the period from October 15-25 to December 
10-20, with the peak between November 1 
and November 30. The normal spring migra- 
tion period extends from March 5-15 to May 
15-25, with the peak between March 25 and 
April 25. 
Habitats 
Red-breasted Mergansers are most abundant 
on the coastal bays. They also are fairly 
common on the ocean, on the salt estuarine 
bays of the Lower Eastern Shore and Lower 
60 
Western Shore sections, and on the brackish 
estuarine bays of the Choptank River, Eastern 
Bay, and Lower Potomac sections. Smaller 
numbers are present at times on the various 
slightly brackish and fresh estuarine bays, 
particularly during the migration periods. 
A few birds stop over on interior impound- 
ments during migration. 
Food Habits 
The gullet and gizzard food contents of 5 
Red-breasted Mergansers were examined. 
Three of these were collected on the fresh 
estuarine bays of the Potomac River, and two 
were taken in salt estuarine bays of the Lower 
Eastern Shore section. The Potomac River 
birds had fed on fish, chiefly sunfish (Lepomis 
sp.) and minnows (Cyprinidae); and on amphipod 
crustaceans (Parathemisto gandichaudii). The lower 
eastern shore birds had fed on fish, including 
Fundulus sp., and on common prawns (Palaemonetes 
vulgaris). 
AMERICAN COOT 
Fulica americana Gmelin 
Transient American Coots occur in fairly 
large local concentrations in the Upper Chesa- 
peake region, and many birds usually remain 
during the winter. ''Crowbill'' is the common 
colloquial name for this species. January in- 
ventories for 1953-58 show that the wintering 
population ranged from 8,700 in 1958 to 74,800 
in 1955, averaged approximately 31,800. This 
average figure represents nearly 2% of the 
continental wintering population and about 5% 
of the Atlantic population. Most hunders donot 
consider the American Coot to be a particu- 
larly desirable game bird, and as a conse- 
quence relatively few birds are harvested, 
Fall migration usually is during the period 
from September 20-30 to December 10-20, 
with the peak between October 20 and Decem- 
ber 1. The normal spring migration period 
extends from March 10-20 to May 5-15, with 
the peak between March 25 and April 25. 
Habitats 
Most of the transient populations of American 
Coots in the Upper Chesapeake region are on 
fresh, slightly brackish, and brackish estuarine 
bays that contain extensive beds of submerged 
plants. Wintering birds appear to prefer brack- 
ish estuarine bays, although many also are 
present on slightly brackish estuarine bays, 
and, during mild winters, quite a few remain 
on fresh-water areas, Occasional transient 
flocks and a few wintering birds occur inother 
waterfowl habitats, including fresh estuarine 
bay marshes, estuarine river marshes, coastal 
impoundments, and interior impoundments, 
