Northern Prairie Wildlife Research Center
Status: Regular migrant and nesting species.
Migration: Rare spring and fall migrant in the Western Upland, casual or absent elsewhere. Spring migrants arrive during the second week of April (earliest-8 April 1959, Burnett County). Dates of peak abundance cannot be determined because of low numbers. Nonbreeding migrants have departed by 20 May. The first fall migrants arrive 25 September to 5 October and the last depart by 1 November (latest-10 November). During both seasons migrants are usually observed in central St. Croix County and at several areas along the St. Croix River in Washington, Polk, and St. Croix counties.
Nesting Season Distribution: The red-necked grebe is a very rare and local nesting species. Green and Janssen (1975) showed a nesting record for Washington County. Apparently this species no longer nests on the Minnesota side of the St. Croix River. Presently, nesting occurs only on prairie wetlands in central St. Croix and extreme southern Polk counties.
The first nesting for the Valley in Wisconsin was recorded in 1973 from East Twin Lake near Roberts. During the summer of 1976, three pairs produced young on Twin Lakes and an additional pair was successful on Oakridge Lake near New Richmond. In 1977, four pairs produced young on Oakridge Lake, one pair on East Twin Lake, and a sixth pair produced young on a small wetland near Star Prairie in Polk County. During 1978-79 breeding populations were greatly reduced with activity restricted to Oakridge Lake (M. Schmidt, personal communication).
Habitat: All 12 nesting records have been obtained on semipermanently and permanently flooded wetlands. These wetlands range in size from 8.5 to 93 ha. Extensive beds of submerged aquatic plants are present on these wetlands. All nests have been located in large beds of softstem bulrush.
Status: Regular migrant, casual nesting species.
Migration: Common migrant throughout the Valley. Spring migrants begin to arrive in the Western Upland during the second week of April (earliest-24 March) and the Northern Highland 1-5 May. Peak abundance occurs during the first week of May and departure by 15 May. Fall migrants begin to arrive during the third week of September. Peak abundance occurs about 15 October when occasional flocks of 50 to 60 individuals are observed on larger lakes. Fall migrants have departed by November 20.
Nesting Season Distribution: One nesting record exists for this region. On 2 July 1951 an adult with a brood of four was observed at the Crex Meadows Wildlife Area, Burnett County. On 14 June 1974, I observed an adult in breeding plumage near Range, Polk County.
Habitat: Horned grebes use a wide range of wetland classes including seasonally, semipermanently, and permanently flooded wetlands. In the Northern Highland, extensive use is made of Forest Bordered Wetlands and occasional use is made of acidic bog wetlands and larger rivers. The Burnett County nesting pair were using a large sedge meadow wetland.
Status: Regular spring and casual fall migrant; four summer records.
Migration: Rare migrant in the Western Upland and Central Plain. There are no records except from Crex Meadows in the Northern Highland. Spring migrants begin to arrive during the last week of April (earliest-20 April 1975, Polk County) and remain through 5 June. Sightings are most often of single or paired birds. Dates for fall migrants are too few to establish a pattern. Fall observations are rare, noted between 10-20 September.
Nesting Season Distribution: One nesting record exists for the Valley. S. D. Robbins found an adult carrying young on its back during the summer of 1968 on East Twin Lake near Roberts, St. Croix County (Robbins 1969a). This is the only known nesting record of the eared grebe in Wisconsin. On 21 July 1952, three eared grebes were observed on Phantom Lake, Crex Meadows, and on 12 July 1956, a single bird was observed at Crex Meadows (Lound and Lound 1956b). During the summer of 1977, a single adult remained on Oakridge Lake, St. Croix County, until 8 August.
Habitat: Eared grebes in the Valley have been found primarily on large permanently flooded wetlands with extensive growths of emergent and submerged aquatic vegetation. The St. Croix County nesting pair used a large semipermanently flooded wetland. Vegetation of that wetland was characterized by extensive beds of coontail surrounded by hardstem bulrush and cattail.
Status: Casual migrant.
Records: Western grebes have been observed twice in spring and once in fall at Crex Meadows, Burnett County. The first record was 30 May 1974, and the second 8 June 1976. The fall observation was on 26 August 1975. All Crex Meadows records were obtained from the Phantom Lake flowage. J. O. Evrard observed a single western grebe on the Fish Lake Wildlife Area near Grantsburg, Burnett County, on 3 June 1979. This bird was observed on Crex Meadows on 11 June 1979 (Tessen 1979b). This species has been recorded three times in St. Croix County: 2 October 1976, two birds on Oakridge Lake near New Richmond; 6 October 1967, three birds on Cedar Lake near Star Prairie; and 12 October 1974, on Oakridge Lake.
Status: Regular migrant and nesting species.
Migration: Common migrant throughout the Western Upland and Central Plain, fairly common in the Northern Highland. Spring migrants arrive during the last week of March (earliest-9 March 1957, Burnett County). Peak abundance occurs 20 April to 1 May. During peak migration, concentrations of 75 to 100 individuals occur on several larger lakes in Chisago, Polk, and Burnett counties. Fall migrants begin to concentrate in early September. Peak fall abundance occurs during the second week of October and departure by 10 November (latest-19 December 1974, Pierce County).
Nesting Season Distribution: Common nesting species throughout the Valley. The largest numbers occur on prairie wetlands of the Central Plain and in the extensive marshes of southwestern Burnett County.
Habitat: The pied-billed grebe occurs most commonly on seasonally and semipermanently flooded wetlands with lush stands of emergent aquatics; cattail and bulrush appear to be preferred for nesting. Nesting pied-billed grebes are also found on large permanently flooded and Alder Thicket wetlands in the Northern Highland. Breeding populations in these habitat types are lower than on seasonally or semipermanently flooded wetlands.