Northern Prairie Wildlife Research Center
Platte River Status: An abundant migrant (especially in the Rainwater Basin area), rare summer and casual winter resident. Occurrence dates at the Mormon Island Crane Meadows, Hall County, extend from 19 February to 10 May. Tout (1947) recorded American wigeon as a migrant in Lincoln County, present 18 March to 18 May, and 11 October to 14 November. Rosche (1979) found American wigeon in the lower North Platte River Valley as a migrant during 8 October to 15 June.
Breeding Range: A rare summer resident in the Sandhills, Platte River Valley, and the Rainwater Basin area of the Eastern Plain. Accidental elsewhere within the study area.
Breeding Population: The population in 1979-1980 was estimated at 530 breeding pairs. Three breeding pairs were present on Waterfowl Production Areas in the Rainwater Basin in 1983 (USFWS files).
Habitat: We found a mean density of 3.2 pairs per km2 on wetlands. American wigeon appears to prefer shallow wetland basins surrounded by wet meadows or partly wooded areas within the study area. Faanes (1982) recorded American wigeon pairs primarily on moderately brackish permanent wetlands on a central North Dakota study area. Kantrud and Stewart (1977) reported that highest densities among American wigeon across North Dakota occurred on temporary (6.0 pairs/km2) and seasonal wetlands (5.0 pairs/km2).
Effect of Habitat Alteration: Loss of water from the Platte River system for agricultural production, drainage of wetlands in the Rainwater Basin area, and conversion of wet meadows and low prairie to cropland have adversely impacted nesting and brood rearing habitat for this species.
Nesting Data: We have no confirmed records of nests or eggs within the study area. Because of the proximity of the Sandhills and Rainwater Basin areas to our study, we believe that American wigeon nests regularly in small numbers here. Egg dates in North Dakota extend from 31 May to 13 July (Stewart 1975).