Many shovelers begin courtship and pair formation 

 on the Chenier Plain before migrating north in late 

 spring. The western portion of the prairie pothole 

 region in Canada is the main nesting area. 



5.3.47 AMERICAN WIGEON {Anas americana) 



The American wigeon migrates to the Chenier 

 Plain in early fall, usually late September through 

 October (Smith 1961). During years when habitat 

 conditions are unfavorable, many birds remain only a 

 short period on the Chenier Plain, then continue 

 migration to tropical wintering areas. Wigeons migrate 

 north through the Chenier Plain in April. 



Wigeons are "pond ducks" that feed mainly on 

 green vegetation. They are partial to sheltered coastal 

 waters containing submerged aquatic plants and they 

 often pilfer scraps of pondweeds from surfacing ducks 

 and coots (Lynch 1967). Early migrants concentrate in 

 large groups on widgeongrass ponds in brackish 

 marshes of the Chenier Plain. As food supplies there 

 become depleted, wigeons feed in freshwater ponds, 

 along lake shorelines, and in pastures (Chabreck 1978). 

 Wigeons prefer aquatic plants and algae, but also eat 

 grass, seeds, and animal material (Bellrose 1974, Smith 

 1973). Hard seeds are concentrated in the gizzard for 

 grit. 



Courtship and pair formation is usually completed 

 in the Chenier Plain. Their large nesting range coincides 

 with that of both the mallard and gadwall, and extends 

 northwest to the Bering Sea in Alaska (Bellrose 1974). 



5.3.48 WOOD DUCK (Aix sponsa) 



Wood ducks constitute only a minor portion of 

 the waterfowl in the Chenier Plain. Wintering popula- 

 tions consist of both resident and migrant birds. 

 Migrants begin arriving in October, reach peak concen- 

 trations during November, and depart in February and 

 March for northern nesting areas (Smith 1961). 



Wood ducks are predominantly found in fresh- 

 water environments, mostly flooded timber or marsh 

 ponds near wooded areas. The roosting area is usually 

 a secluded pond with low overhead cover, often 

 composed of buttonbush. 



Wood ducks feed by dabbling. They select seeds 

 and vegetative parts of aquatic plants, plus fruits and 

 nuts of trees and shrubs. Brooding areas usually con- 

 tain dense growths of submerged aquatic plants, and 

 emergent plants along the shoreline. These plants har- 

 bor insects which are the major food of the ducklings 

 (Johnsgard 1975). 



This species is a cavity nester and usually selects a 

 hollow tree near water. Cavities range from 10 cm to 

 2 m (4 in to 6 ft) deep. The down-lined nest may be 

 constructed at heights up to 15 m (50 ft). The species 

 readily utilizes artificial nesting structures, and local 

 populations can be greatly increased by supplying arti- 

 ficial nesting sites. The number of natural cavities avail- 

 able for nesting is a limiting factor to the species 

 (Bellrose 1974). 



5.3.49 REDHEAD (Aythya americana) 



Only a small portion of the redhead population 

 that migrates down the Mississippi and Central Flyways 

 winters on the Chenier Plain. Large flocks do, however, 

 winter in the Chandeleur Islands area and Laguna 

 Madre area of southern Louisiana (Smith 1961, Single- 

 ton 1953). Redheads arrive on the Gulf coast in late 

 October and November and remain there for the winter 

 (Smith 1961). Northward migration in the spring 

 begins in early February, and by mid-March most birds 

 have departed. 



In the northern Gulf, redheads commonly inhabit 

 offshore waters; however, in the Chenier Plain, the 

 species limits its activities to inland open waters and 

 impounded marshes. Although redheads are divers, 

 they often use shallow marsh ponds, and feed by 

 tipping. They feed primarily on aquatic plants, and 

 winter in areas where these plants are readily available. 



Redheads nest in the Dakotas and throughout the 

 prairie pothole region of southwestern Canada. Hens 

 often lay eggs in the nests of other redheads or even 

 other waterfowl. The foster parent then hatches the 

 eggs and rears the young (Bellrose 1974). 



5.3.50 RING-NECKED DUCK (Aythya collaris) 



Ring-necked ducks begin arriving on the Chenier 

 Plain in mid-October. Populations gradually increase 

 during the fall and reach a peak in late December and 

 early January. The species begins the northward migra- 

 tion in February, but the major exodus does not take 

 place until mid-March (Smith 1961). This species is 

 found mostly on freshwater lakes that contain submer- 

 ged aquatic vegetation. Largest concentrations of these 

 ducks in the Chenier Plain occur at Lacassine National 

 Wildlife Fefuge (Smith 1961). 



Ring-necked ducks feed on succulent parts of 

 aquatic plants. Seeds of species such as watershield, 

 bulrush, and pondweed are also eaten by the birds. 

 Animal material, mainly mollusks, make up about 25% 

 of the diet (Johnsgard 1975). 



These birds are common nesters in the Great Lakes 

 region and across midwestern Canada (Johnsgard 



1975). 



5.3.51 CANVASBACK {Aythya valisineria) 



Small flocks of canvasbacks begin arriving on the 

 Chenier Plain in early November, continue to arrive 

 throughout the winter, and reach highest numbers in 

 January; however, no more than a few thousand birds 

 usually overwinter. Spring departure begins in Febru- 

 ary and is completed by late March (Smith 1961). 



The coastal lagoons of Louisiana and Texas were 

 once a major winter concentration area for canvas- 

 backs, but numbers gradually dwindled to the point 

 where the bird is rarely seen there. Canvasbacks are 

 excellent divers and frequent lakes that support stands 

 of submerged and floating-leaf plants. 



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