Northern Prairie Wildlife Research Center
Breeding Range. (Fig. 9). Common in the Turtle Mountains, throughout the Northeastern and Southern Drift Plains, and Missouri Coteau; locally common on the Northwestern Drift Plain, particularly on the J. Clark Salyer, Upper Souris, and Des Lacs National Wildlife Refuges; fairly common in the northern portion of the Agassiz Lake Plain Region (Pembina, Walsh, and Grand Forks Counties); uncommon and local elsewhere in the state.
Breeding Habitat. This species is of regular occurrence in most fresh, slightly brackish, and moderately brackish seasonal and semipermanent ponds and lakes that cover 1 acre or more. Occasionally, it also inhabits brackish semipermanent ponds, river impoundments, and stock ponds. Ordinarily, breeding Pied-billed Grebes are more closely associated with emergent cover than other species of grebes. They are especially characteristic of wetlands that contain fairly extensive stands of emergent shallow-marsh or deep-marsh vegetation with adjacent open-water areas. Common emergent plants in wetlands inhabited by Pied-billed Grebes include giant burreed, tall mannagrass, whitetop, slough sedge, cattails, hardstem bulrush, slender bulrush, and river bulrush.
Nesting. Breeding Season: Early May to mid-September; peak, late May to early August. Extreme egg dates (140 nests): May 7 [1963] in Stutsman County (H. A. Ranted) to August 20 [1962] in Stutsman County (RES). Extreme dates of dependent young (109 broods): First week of June [year ?] in Towner County (Judd 1917) to September 14 [1962] in Stutsman County (RES).
The floating nests of this species are usually located in semiopen or dense emergent cover, rarely on open water. Common variations in recorded species composition of nesting cover were: hardstem bulrush, 32 nests; whitetop, 7 nests; mixture of hardstem bulrush and whitetop, 6 nests; mixture of whitetop and slough sedge, 5 nests; cattails, 5 nests; mixture of cattails and hardstem bulrush, 5 nests; and mixture of hardstem bulrush and slough sedge, 5 nests. Other emergent species that comprised nesting cover with less frequency included giant burreed, tall mannagrass, river bulrush, alkali bulrush, and softstem bulrush. Nests were composed of sodden, often partially decayed vegetative debris, including stems and leaves of emergent plants and submerged aquatic vegetation. Water depths at 82 nest sites ranged from 11 to 37 inches and averaged 25 inches.
Indicated clutch size (74 nests): 4 to mean, 6.7 eggs. 11 eggs;
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| Figure 9. Breeding Range of Pied-billed Grebe. |
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U.S. Department of the Interior |
U.S. Geological Survey
URL: http://www.npwrc.usgs.gov/resource/birds/bbofnd/species/60.htm
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Menlo Park, CA [caww54]
