283 
Two large areas which include the best potential breeding habitat in Maryland 
were selected for systematic sampling. Both areas are known to contain relatively 
high populations of breeding waterfowl. One area comprises 144 Square miles and 
is considered a ditched coastal marsh type. It includes marshes from the border 
of Delaware to Chincoteague, Virginia and is marked Area 1 on Map l. A total of 
88 linear miles of transects was flown in this area. 
Another area totaling 538 square miles is considered an unditched estuarine 
type and includes all tidal marshes on the eastern shore from the Little Choptank 
River to Crisfield, Maryland. It is indicated as Area 2 on Map 1. In this type, 
563.2 miles of ‘transects were flown. 
Since little or no data were available for many potential breeding areas, a 
considerable amount of reconnaissance flying over such areas was necessary in 
order to determine if waterfowl populations were high enough to measure by aerial 
methods, Over the Delmarva Peninsula - exclusive of the two areas previously 
described - 438 miles of overland transects were flown for reconnaissance purposes. 
Over the part of Maryland that is located on the western shore between the Potomac 
and Patapsco Rivers, 231 miles were covered. Over the Virginia mainland no over- 
land transects were flown. Flights were confined to the shorelines of rivers and 
creeks, and data was broken down according to miles of rivers and creeks flown. 
Areas covered by reconnaissance flights, exclusive of rivers, are shown on Maps 
1 and 2. 
In addition to the overland transects flown in Maryland, special flights were 
made along the shorelines of all major rivers. A single flight was made over the 
middle of narrow rivers. Both shorelines of wide rivers were covered. 
All flights were made at an altitude of 200 feet. On overland transects, 
waterfowl seen on a strip of 1/16-mile wide on either side of the plane (totaling 
1/8-mile) were tabulated. On river transects all waterfowl along the shoreline 
were counted, The transects were divided into eight mile segments and the number 
of waterfowl recorded for each segment, 
The transects over the Peninsula were flown on July 14, 15, 16 and 17. The 
Virginia mainland transects were flown July 21 and 22. Flights over the Maryland 
mainland were made August 5 and 6. 
Success of the Season 
Table I summarizes the data for the two areas that were systematically 
sampled. It should be noted that the average brood size is computed from the total 
number of broods seen on all flights over the Delmarva Peninsula, and not merely 
from the number observed in either type. Brood sizes varied from two to four. 
All broods were Class III black ducks. Broods of other species were not observed. 
Table I - Brood Counts in Estuarine and Ditched Coastal Types 
a i ag Aa a a WA cea AS me NCO i OR AE SE 
Area in Miles of Area of No. of Average Size 
Sq. Miles Transects Transects Broods of Broods 
Type in Sq. Mi. 
a ace c_ ANSON 
Unditched Estuarine 538 563.2 70.4 26 5.21 
88.0 11.0 4 5.21 
Ditched Coastal 144 
