American Wigeon Anas americana Gmelin        Field Guide IDs: NG-80; G-48; PE-5O; PW-pl 14; AE-pl 106; AW-pl 119; AM (I)- 170 Nest Location Nest Type Eggs & Mating System Dev. & Parental Care Primary & 2ndary Diet.. Foraging Strategy F I: 23-25 DAYS PRECOCIAL 2 F 7-10 (6-12) MONOG F: 37-48 DAYS F AQUATIC INVERTS BREEDING: Marshes, freshwater areas with exposed shoreline, lakes, islands. 1 brood. DISPLAYS: See: Duck Displays. NEST: Often far from water. Concealed; filled with dry grass and plant stems, lined with finer materials. Down added as incubation advances. EGGS: White. 2.1" (54 mm). DIET: Grass, grain, aquatic veg, fewer seeds than most dabblers; aquatic invertebrates, mollusks, insects. CONSERVATION: Winters s to n S.A NOTES: Pair bond lasts through first or second week of incubation. Male reproductive success related to persistent aggression, dominance, mate attentiveness, and displaying, esp aerial chases. Males in full plumage acquire mates earliest; males unable to acquire mates usu smaller and have lower energy (protein and lipid) reserves. If young disturbed, female feigns injury while young scatter; when young hidden, female flies away. STANFORD. NOTES: Uncommon winter visitor at Lagunita, usually seen foraging in shallows at the edge of the lake. ESSAYS: Bird Communities and Competition; Dabblers vs. Divers; Diet and Nutrition; Metallic Poisons; Monogamy; Feathered Nests; Distraction Displays. REFERENCES: Bellrose, 1976; Gooders and Boyer, 1986; Wishart, 1983.