36 



NORTH AMERICAN FAUNA 73 



ing from 3 April 1968 and 8 April 1971 in Burnett County and 26 March 

 1976 in St. Croix County, to 12 April 1971 in Washington County. Most rec- 

 ords occur during 5-20 May; the latest record was 2 June 1961 at Crex 

 Meadows, Burnett County. 



Rare fall migrant with records only from Burnett and St. Croix counties. 

 Fall dates range from 16 September to 10 November 1964 (Crex Meadows). 

 Most records are from 5-20 October. White-fronted geese are usually ob- 

 served in fall in flocks of three to six. The largest flock recorded (12) was 

 observed in St. Croix County on 28 March 1978. 



Habitat: Spring migrants are usually observed on temporarily or semiper- 

 manently flooded wetlands. During fall migration most observations consist 

 of birds in feeding flocks with other geese in corn or oat stubble fields. 



Snow Goose {Chen caerulescens) 



Status: Regular migrant, accidental in summer and winter. 



Migration: Rare spring and fairly common fall migrant throughout the 

 Valley; locally common at Crex Meadows, Burnett County, during fall 

 migration. Spring migration begins with the arrival of small scattered flocks 

 5-15 April (earliest— 16 March 1966, Washington County). No large popula- 

 tions occur during spring migration and most birds depart by 15 May 

 (latest— 3 June 1977, St. Croix County). Fall migrants arrive about 20 Sep- 

 tember (earUest— 13 September 1974, Burnett County). Peak faU popula- 

 tions usually consist of groups totaling 200 to 300 individuals per county. 

 Occasionally, exceptionally large concentrations occur at Crex Meadows 

 WildHfe Area, including 11,650 on 2 November 1971 (WDNR files). Normal 

 peak fall populations occur 15 October to 1 November and departure by 

 20 November. 



Summer: N. R. Stone recorded a blue phase snow goose in molt in Black 

 Brook Township, Polk County, on 20 June 1951. Another blue phase goose 

 was recorded at Crex Meadows, Burnett County, on 7 July 1953. 



Winter: P. D. Tweet observed a flock of six in Troy Township, St. Croix 

 County, on 1 January 1977. These birds were probably late migrants. 



Habitat: Primary habitat use of migrant snow geese consists of temporarily 

 or semipermanently flooded wetlands. Adjacent agricultural fields, both row 

 crops and hay, are heavily used for feeding. 



Mallard (Anas platyrhynchos) 



Status: Regular migrant, nesting species, and winter resident. 



Migration: Common to locally abundant spring migrant in the Western 

 Upland and Central Plain, fairly common to locaUy abundant in the North- 

 ern Highland. Determination of spring arrival dates is compounded by the 

 presence of wintering birds. Movements of birds into the region are observed 

 in late February with increases along the St. Croix River. Birds gradually 

 move north arriving in the Northern Highland about 15 March. Peak spring 



