American Wigeon

Anas american
STANFORD LOCATIONS:

Uncommon winter visitor at Lagunita, usually seen foraging in shallows at the edge of the lake.
 
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.
ESSAYS: Bird Communities and Competition; Dabblers vs. Divers; Diet and Nutrition; Metallic Poisons; Monogamy; Feathered Nests; Distraction Displays.
REFERENCES: Eiserer, 1976; Knupp et al., 1977, Paszkowski, 1982; Wheelwright, 1986.

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Except for Stanford Locations, the material in this species treatment is taken, with permission, from The Birder's Handbook (Paul Ehrlich, David Dobkin, & Darryl Wheye, Simon & Schuster, NY. 1988).