American Wigeon - Anas americana
American Wigeon, Standing - Anas americana - Drake (Male)
General Description
Commonly know as the "Baldpate". Adult male: forehead and crown white; broad dark green patch surrounding eye passing to nape; rest of head and uper neck buffy white heavily speckled with black; breast, sides, and flanks pinkish brown contrasting with white belly and sides of rump, scapulars and back pinkish brown. Bill bluish gray with black tip. Adult female: crown brownish black, streaked with creamy white; rest of head and upper neck whitish with dusky streaking; back and scapulars grayish brown; breast, sides, and flanks pale reddish brown contrasting with white belly. Bill grayish with black tip. (Mowbray, Thomas. The Birds of North America, No. 401, 1999).
Distribution
Montana Range
Migration
At Red Rock Lakes National Wildlife Refuge in June 1959, numbers rose to 40,000. Normal migration in the Bozeman area is from March 10 to May 20 and from September 10 to November 20. Peak numbers are reached in April and September (Skaar 1969).
Habitat
Breeds near shallow, freshwater wetlands: sloughs, ponds, small lakes, marshes, and rivers. For nesting prefers areas with upland cover of brush/grass vegetation in the vicinity of lakes or marshy sloughs. (Mowbray 1999). Comments on habitat use are in Holm 1984. In the Bozeman area, they prefer lakes and ponds, except in winter when they prefer open streams (Skaar 1969).
Food Habits
During winter and migration almost entirely vegetarian - stems and leafy parts of acquatic plants, leafy parts of upland grasses and leafy parts and seeds of various agricultural crops. During breeding season there is a shift toward a greater proportion of seeds and fruits and a substgantial shift toward more nonplant foods - insects, mollusks and crustaceans. (Mowbray 1999).
Ecology
At Freezeout Lake, the major cause of unsuccessful nests was skunk predation. Numbers are increasing in the Fortine area.
Reproductive Characteristics
Brood size averages 6.1 on rest-rotation grazing pastures in north-central Montana (Gjersing MS). Nesting occurs from mid-May to mid-August, with the peak early in July. Hatching dates at Freezeout Lake were from June 11 to July 20, and in the Fortine area the average brood size was 7.