The Pied-billed Grebe is the only living species in its genus (Ehrlich et al. 1988). It is known for its ability to disappear quickly when threatened (Cornell Lab of Ornithology 2003, Ehrlich et al. 1988, and Bailey 1931), and is therefore sometimes referred to as 'sac-a-plomb' (Bailey 1931) or 'lead sinker'. This bird is rarely seen flying partially because it migrates at night (Cornell Lab of Ornithology 2003). An unusual physical characteristic of grebes is that they do not have webbed feet, but lobes on each toe for gaining surface area to push through the water.

Length: 13 in (33 cm) (Kaufman 2000).

Physical characteristics: The entire body is dark gray, but with a blackish head. The bill is thick and white with a black ring. The ring is faded during non-breeding seasons. Immature birds are a paler gray with a very faded ring on bill.

Voice: 'kuh-kuh-kuh-kuh-kowp, kuh-kowp' (Kaufman 2000).

Breeding habitat: Breeds in wetlands such as lakes and ponds with an abundance of floating vegetation. It may also breed in slow moving streams and marshes (Ehrlich et al. 1988).

Mating system: This species may be monogamous, but more research is needed. Courtship is vocal, rather than displayed, and is carried out with a duet call (Ehrlich et al. 1988).

Nest: Both the male and female help build the floating nest, which is anchored in the water to emergent vegetation. The nest is a platform type made of decaying vegetation (Ehrlich et al. 1988).

Eggs: The eggs are bluish-white, with no markings, 1.7? (43 mm). They may look marked from brown nest stains. Typically, five to seven eggs are laid in a clutch. Pairs will brood once a year, but in the south, they made brood twice (Ehrlich et al. 1988).

Diet: Feeds mainly on aquatic invertebrates and may also feed on small fish. It forages by diving below the surface to catch organisms (Ehrlich et al. 1988).

Note:
In Tennessee, the breeding population is rare and imperiled and is threatened with extirpation in the state (Withers et al. 2004), but is regularly seen (Tennessee Ornithology Society 2006).