290 
WATERFOWL BREEDING GROUND SURVEY IN DELAWARE 
Everett B. Chamberlain 
Introduction 
For the third consecutive season a breeding ground survey was carried out 
in Delaware. This survey, aimed at finding out as much as possible about water- 
fowl breeding in the State, utilizes both ground and aerial observations and both 
permanent and part-time personnel. In addition to the aerial method (100 percent 
counts) used last year, the aerial transect method was used this year. 
Methods Used in Sampling and Area Covered 
In order to have figures directly comparable to those obtained in 1951, 
broods were again tallied during the regular monthly aerial migration counts, 
These counts cover the entire State and all waterfowl that can be seen from the 
air are counted, Also, and again in order to have comparable data, two of the 
ground study areas used last year were covered again in 1952. Aerial transects, 
based on a sound sampling design, were also used. 
Weather and Water Conditions 
Weather and water conditions in Delaware during the breeding season were 
abnormal. During the early part of the season there was an excess of rainfall, so 
much of an excess that during the drought that followed many farmers had ponds in 
the middle of their cultivated fields. It seems likely that the high waterfowl popula- 
tions in March and April were largely the direct result of this unusual amount of 
surface water. It is felt that many ducks delayed the northward flight because more 
than the normal amount of feeding and resting places were available. The differences 
in square-mile densities during the breeding seasons of 1951 and 1952 are shown in 
the accompanying graph. They are shown numerically, together with total population 
figures in Table I. 
Table I - Comparison of Total and Square Mile Waterfowl Populations in Delaware 
1951 and 1952 
Total Population Waterfowl per Square Mile 
1951 1952 1951 1952 
March 26, 374 38,797 128.48 189.00 
April 5,180 9,919 25.23 48.32 
May 1,193 1,056 5.81 5.14 
June . 1,221 : 1,322 5.95 6,44 
July 1,600 * Z2,007 7.79 * 9.78 
* No count; estimated, 
With the exception of the increases noted in March and April, weather and 
water conditions apparently had no effect on breeding populations of waterfowl in 
Delaware. 
