298 
WATERFOWL NESTING SEASON ON NATIONAL WATERFOWL REFUGES, 1952 
Richard E. Griffith 
Comparison of refuge breeding ground surveys for the past season leaves 
no doubt as to the wide variation in production which may result from heavy run- 
off or excessive rainfall, both of which determine the pattern of water levels on 
nesting grounds. In some instances, flood conditions provided temporary nesting 
habitat, thus compensating for the loss of territory normally available. In several 
cases, however, comparatively abrupt shorelines resulted in progressive loss of 
nesting habitat as water levels rose. This relationship is clearly indicated in 
production records on several refuge nesting grounds. Obviously, the population 
trends exhibited by individual species under these conditions are not a true reflection 
of general species trends for the region. 
Continued observation and study of the relationship between livestock grazing 
and waterfowl nesting indicate considerable local variations in waterfowl production, 
depending upon the growing season, the character of the date when grazing begins 
and the intensity of livestock use. On the Malheur Refuge, grazing intensity con- 
Sistent with good range utilization standards resulted in close cropping of shoreline 
vegetation and considerable loss of nests through trampling. At the present time 
evidence points to the need for reappraising the livestock-waterfowl relationship 
in primary nesting areas where below average precipitation during the nesting 
season may result in increased grazing and livestock movement in neSting habitat. 
Refuge population trends as reported below were established through a combi- 
nation of pre-season surveys to determine the number of nesting pairs and followed 
later by a series of brood surveys so distributed through the season as to determine 
the significant variations in brood size and species, as compared with previous 
years, and, in addition, evaluate management practices which might be modified 
or initiated to increase the total production another season. 
Atlantic Flyway 
A cold, wet spring season delayed nesting somewhat, though appeared to have 
no significant effect on refuge breeding populations, Black duck, mallard and gadwall 
production on the coastal refuges varied little from that of 1951. Prolonged drought 
which began in the Pea Island, North Carolina area during the nesting season did not 
interfere with production on the refuge impoundments. Gadwalls showed an increase 
for the fourth consecutive year. 
Total waterfowl production on the Montezuma National Wildlife Refuge in 
central New York was down 30 percent this year as compared with figures for 1950 
and 1951, although the average brood size was larger. 
There was evidence of increased predation by red foxes, as is to be expected 
in areas where the species has shown a definite upward trend. Predation by 
raccoons is still high on coastal marshes. 
