A small, stocky, and poorly buoyant water bird, 31 to 38 cm in length (Cramp 1977), with small, narrow wings, feet placed far back, and a blunt-ended posterior. During the non-breeding period, the bill is unmarked, the throat is white, and the white rear becomes more conspicuous. As adults, sexes are alike, whereas juveniles are distinguished by the lack of a white orbital ring, an unmarked bill, darker brown sides of the head and neck, and a whiter underbelly (Palmer 1962). Downy chicks have a striking, zebra-like pattern of black and white stripes, interspersed with reddish-brown spots, and a bare loral area (Palmer 1962, Storer 1967).
VOCALIZATIONS: During territorial defense, males emit a distinctive prolonged call, a loud "cow-cow-cow-cow-cow- cowp...cowp...cowp...
". This call is reminiscent of cuckoos (Palmer 1962), and enables communication over several hundred meters in nesting habitats dominated by dense, visually restricting vegetation. A variety of other calls are also produced during the breeding season (see Palmer 1962), but during the non-breeding season generally silent.
NEST: Build sodden, floating nests of rotting and green plant material and mud. Often anchored to growing, emergent plants. In Iowa, 138 nests averaged 38 cm in diameter (Glover 1953).
EGGS: elliptical to sub-elliptical, approx. 44.3 by 30.1 mm, smooth and nonglossy (Baicich 2005, Arnold 1989). Although white or tinted bluish or buff when laid, eggs gather a heavy, brown stain from the wet, organic matter comprising the nest.
MOLT: Molt is poorly known. Palmer (1962) noted that a complete molt into basic plumage takes place in autumn, with considerable individual variation in its timing and duration (Cramp et al. 1977). Flight feathers are lost simultaneously, prior to loss of body feathers. Complete molt takes one to two months. Basic molt and late nesting may occur simultaneously (Otto and Strohmeyer 1985). A partial molt into alternate plumage occurs in spring (Palmer 1962).
For a comprehensive review of the conservation status, habitat use, and ecology of this and other Montana bird species, please see Marks et al. 2016, Birds of Montana.
A short, stout, chicken-like bill with a broad, black band in the middle, large head and elongated neck, white orbital ring, black throat patch and forehead, and drab, brownish plumage throughout except for white under the tail (Palmer 1962, Cramp 1977).
Western Hemisphere Range
There are no noticeable migration periods in Bozeman area, other than early and late dates (Skaar 1969).
In the fall, Bozeman area, the birds move away from marshes and into open water (Skaar 1969). It seeks similar habitat during migration and wintering, as long as it is ice free. Fresh water to moderately brackish ponds are part of its breeding area. (Muller & Storer, 1999)
The Pied-billed Grebe is opportunistic. It takes what is available and will eat fish, crustaceans (especially crayfish) and aquatic insects and their larvae (Muller and Storer 1999)
Active nests seen in late April and early May. Chicks observed in July (Skaar 1969). In the Fortine area, third-grown young seen June 18, half-grown young August 6, and nearly grown young on Ninepipe NWR on July 11. A complete clutch is laid in 4 to 10 days. The hatch last 2 to 7 days after approximately 23 days of incubation. A second brood is common if nest or eggs are lost (Muller and Storer 1999)