New York Natural Heritage Program
Pied-billed Grebe
Podilymbus podiceps (Linnaeus, 1758)
Birds

Identifying Characteristics [-]
Pied-billed grebes are small, stocky, poorly buoyant waterbirds, about 31-38 cm in length, with small, narrow wings, and feet placed far back, with 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, the 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 zebra-like pattern of black and white stripes, interspersed with reddish-brown spots (Palmer 1962). VOCALIZATIONS: Territorial males have a distinctive prolonged call, a loud "cow-cow-cow-cow-cow- cowp...cowp...cowp...". Several other calls are also produced during the breeding season, but during the non-breeding season they are mostly silent. NEST: Grebes build sodden, floating nests of rotting and green plant material and mud averaging 38 cm in diameter (Glover 1953), often anchored to growing emergent plants. EGGS: Elliptical to subelliptical, approximately 44 x 30 mm, smooth and nonglossy (Harrison 1978). Although white or tinted bluish when laid, the eggs gather a heavy, brown stain from the wet, organic matter in the nest.

Best Life Stage for Proper Identification [-]
Mature adults are easiest to identify and the sexes are similar. However, the downy chicks of pied-billed grebes have a striking, zebra-like pattern of black and white stripes, interspersed with reddish-brown spots, that makes them readily identifiable as well.

Behavior [-]
Grebe's are very secretive birds that will slowly submerge underwater with only their eyes and nostrils showing in order to escape danger. Downy chicks ride on the adults back, even when they dive underwater. Adults consume their own feathers and also feed them to young, presumably to protect the stomach and trap fish bones. Hard indigestible items are felted together with feathers and regurgitated as pellets. Grebes migrate nocturnally, landing before dawn at the nearest waterbody and are more social outside the breeding season. During breeding pied-billed grebes are an aggressive, highly territorial bird, threatening, chasing and attacking conspecifics and other species. They are reluctant to take flight, needing a long running start across open water to become airborne. Seasonally monagamous, both sexes build the nest and add plant material and mud as the season progresses and the nest slowly sinks. Air-pockets and trapped gases generated by the fermenting and rotting vegetation give buoyancy to the nest. The floating, rotting nest generates substantial quantities of heat (Davis et al. 1985) and may allow the adults to abandon the nest at night to avoid predation risk (Nuechterlein and Buitron 2002). The young are precocial, making their first successful catches of food (fish, insects) at 10-12 days post-hatching and they are capable of flight only 35 days after hatching.

Diet [-]
Pied- billed grebes are opportunistic carnivores, the diet being dominated by crayfish (31% by volume), insects (46%), primarily Odonates (dragonflies), Heteroptera (true bugs), Coleoptera (beetles) and fish (24%), including catfish, eels, perch, sunfish, suckers, carp, sciulpins, killifish, sticklebacks, and minnows. There is a strong seasonal shift in the diet, fish being most important during the nonbreeding season, while dragonfly nymphs constituted 34% of the diet in late summer and are an important food item for chicks (Muller and Storer 1999). The diet also includes smaller amounts of snails, small frogs, tadpoles, aquatic worms and leeches. In wetlands where fish are not prevalent, Ambystomatid salamander adults and larvae play a key role in the diet (Osnas 2003).
Pied-billed Grebe Images
click to enlarge
The Best Time to See
In New York, the pied-billed grebe is a rare to uncommon local breeder; a fairly common migrant, more numerous in the fall; and a rare but regular winter visitant (Levine 1998). Migratory grebes usually arrive on the nesting grounds by early March, shortly after ice out, and courtship commences in early April with nesting activity initiated by mid-April. The peak vocalization period for pied-billed grebes at study sites in western New York was from late-April through mid-May with breeding activity vocalizations dropping off through June (Lor and Maleki 2002).
J F M A M J J A S O N D
Present Breeding
The time of year you would expect to find Pied-billed Grebe present (blue shading) and breeding (orange shading) in New York.
Similar Species
  • Common Moorhen (Gallinula chloropus)
    The moorhen's call can be mistaken for a pied-billed grebe's, but is more nasal. This species has a reddish forehead shield, yellow tipped bill, with a white streak on its flanks.
  • American Coot (Fulica americana)
    Coots have an all black body and pale bill extending onto the forehead.