Master of Science (MS)


Renewable Natural Resources

Document Type



I examined nest attendance patterns for 132 Gadwall (Anas strepera) females breeding in the prairie pothole region located in Towner County, North Dakota from May to July 2000 - 2001. Overall, Gadwall had a daily incubation constancy of 76.5 ± 10.8%, and daily recess frequency of 2.2 ± 1.1 with each recess lasting 179.8 ± 133.8 minutes. Unlike other waterfowl species, Gadwall increased incubation constancy and decreased recess frequency as daily high temperature increased and showed no change in constancy with precipitation. Gadwall incubation constancy did not fit the body-size hypothesis, as Gadwall have a lower incubation constancy compared to species smaller in size. This may be because Gadwall have the latest peak clutch initiation of all dabbling ducks, providing the advantage of dense nesting cover and warmer ambient temperature compared to earlier nesting species. Of the 132 females, 19 (14%) delayed nocturnal incubation resulting in a significant difference in incubation constancy (P= 0.001) and recess frequency (P = 0.001) from those that did not delay nocturnal incubation. However, components of the incubation rhythms, after the onset of nocturnal incubation were similar for both groups.



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Committee Chair

Frank Rohwer