BIRDS OF THE ST. CROIX RIVER VALLEY 



41 



birds are gone by 20 October (latest— 2 December 1973, Washington 

 County). 



Nesting Season Distribution: Abundant nesting duck on prairie wetlands of 

 St. Croix, Polk, and Washington counties. Prehminary data collected by the 

 WDNR (Peterson 1978) show a breeding density of about 1.7 pairs per km=^ 

 in St. Croix and Polk counties. At Crex Meadows, blue-winged teal are the 

 most abundant breeding duck, averaging nearly 42% of all breeding pairs 

 observed from 1957-78 (WDNR files). 



Habitat: Blue-winged teal use a wide variety of wetland types for nesting, 

 ranging from sedge meadows to bog wetlands. Largest densities occur on 

 seasonally, semipermanently, and permanently flooded wetlands containing 

 an abundance of submerged and emergent aquatic vegetation. To a lesser 

 extent, breeding pairs also use stock ponds and dugout ponds created by the 

 Soil Conservation Service. Lowland Deciduous Forest habitat along streams 

 and rivers is regularly used. 



Cinnamon Teal (Anas cyanoptera) 

 Status: Casual spring and fall migrant. 



Records: Cinnamon teal have been observed four times at Crex Meadows, 

 Burnett County: 14 April 1953 (six birds); 25 April 1955 (two); 8 May 1956. 

 Hunt and Jahn (1968) observed a male cinnamon teal at Crex Meadows on 

 21 April 1968. One bird was observed in Washington County on 16 April 

 1963 (Honetschlager 1963). Roberts (1932) cited the collection of a male 

 cinnamon teal near Stacy, Chisago County, "sometime between October 5- 

 15, 1923." A second male was obtained "at almost identically the same 

 place" on 15 September 1924. 



American Wigeon {Anas americana) 



Status: Regular migrant and casual nesting species. 



Migration: Fairly common migrant in the Western Upland; uncommon in 

 the Central Plain and Northern Highland. Goddard (1975) found that Ameri- 

 can wigeon made up 2.2% of all waterfowl and 4.5% of the dabbhng ducks 

 using St. Croix County wetlands during spring migration. 



Spring Migrants arrive in the Western Upland 20-30 March; the earliest 

 birds occur along the St. Croix River. Arrival is somewhat later at Crex 

 Meadows, Burnett County, where the average arrival is 8 April. Movement 

 into the Valley is very rapid and peak populations are usually observed 

 10-25 April. Departure from the Valley usually occurs 10-25 May. 



Fall migrants arrive in late August and build up rapidly, reaching peak 

 populations 25 September to 10 October. The largest number observed at 

 Crex Meadows (400) occurred on 3 October 1970. In St. Croix County, fall 

 peak populations of 200 to 300 birds are common and 720 were observed on 

 3 October 1976. Departure from the Valley occurs 1-10 November (latest— 

 15 December 1974, Washington County). 



