32 



NORTH AMERICAN FAUNA 73 



Willow River near New Richmond. 



Habitat: Washington and St. Croix county colonies exist in live trees of 

 Lowland Deciduous Forest. Nests at Fish Lake WildUfe Area occur in jack 

 pine trees killed by the rising waters of Grettum Flowage. 



Snowy Egret [Egretta thula) 

 Status: Accidental, one record. 



Record: Norman Stone observed a single snowy egret at Crex Meadows, 

 Burnett County, on 4 and 5 May 1959 (Stone 1959a). 



Louisiana Heron {Hydranassa tricolor) 

 Status: Accidental, one record. 



Record: One Louisiana heron was observed at Crex Meadows, Burnett 

 County, on 7 July 1977 (Tessen 1977). 



Black-crowned Night Heron (Nycticorax nycticorax) 

 Status: Regular migrant and nesting species. 



Migration: Uncommon and local migrant in the Western Upland, rare in 

 other regions. Spring migrants arrive in the Western Upland 10-15 April, 

 reaching peak abundance 1-10 May. Average date of spring arrival in Bur- 

 nett County is 10 May. Fall migration begins 25 August to 1 September and 

 departure by 1 October (latest— 28 November 1967, Washington County). 



Nesting Season Distribution: Rare and local nesting species. Confirmed 

 breeding records have been reported only from St. Croix and Burnett coun- 

 ties; however, several summer observations have been made in Washington 

 County. Roberts (1932) stated that one of the most northerly colonies in 

 Minnesota occurred on the St. Croix River in Pine County. Unfortunately no 

 dates or locations are provided. 



Habitat: Three nesting colonies of black-crowned night herons are known in 

 this region. Habitats associated with these colonies include wetland habitat 

 dominated by bulrush and cattail. In proximity are small groves of alder and 

 willow used for nest platforms. 



Yellow-crowned Night Heron (Nyctanassa violacea) 

 Status: Accidental, one record. 



Record: Green and Janssen (1975) cite a 6 June 1964 record from St. Croix 

 State Park, Pine County. 



Least Bittern {Ixobrychus exilis) 

 Status: Regular migrant and nesting species. 



