Pied billed Grebe (Podilymbus podiceps)

[order] Podicipediformes | [family] Podicipedidae | [latin] Podilymbus podiceps | [UK] Pied-billed Grebe | [FR] Grebe a bec bigarre | [DE] Bindentaucher | [ES] Zampullin Picogrueso | [IT] Podilimbo | [NL] Dikbekfuut

Subspecies

Physical charateristics

A small grebe with a thick, relatively short bill, the Pied-billed Grebe is greyish-brown with lighter underparts. Juveniles and adults have similar plumages, but during the breeding season adults have black at the throat and a whitish bill with a black band.
Pied-billed Grebes are less social than most species of grebes and are rarely found in flocks. When disturbed, they dive headfirst under water, or they sink slowly into the water until only their heads are above water, like submarine periscopes. The courtship displays of Pied-billed Grebes are less ritualized than those of other grebes, but still include much calling, sometimes in duet.

Listen to the sound of Pied-billed Grebe

[audio:http://www.aviflevoland.nl/sounddb/P/Pied-billed Grebe.mp3]

Copyright remark: Most sounds derived from xeno-canto

Range

Pied-billed Grebes are still common and widespread in the Nearctic region, although there is evidence of recent declines, especially in the Northeast, where they have become extremely rare in some places for reasons unknown. Habitat loss is the major threat, although Pied-billed Grebes will nest in created and restored wetlands. Rare vagrant to Europe. In suriname an uncommon inhabitant and breeder of marshes and vegetated swamps.

Habitat

During the breeding season, Pied-billed Grebes are found at low elevations in ponds, lakes, and marshes. Nesting areas typically have emergent vegetation to which these birds anchor their nests and open water in which they can forage. During the winter they are found on both fresh and salt water, although they are much more likely to be found on fresh water. More open water is used during winter, as the birds do not have nests to anchor at this time. Pied-billed Grebes often use areas near rivers, typically bodies of still water. In migration Pied-billed Grebes can be found at higher elevations, even in mountain lakes.

Reproduction

Both parents build a nest in shallow water in a marsh. Floating, or built up from the bottom, the nest is a dense mat of plant material anchored to emergent vegetation. The nest can be approached from under water. The female lays five to seven eggs that both parents help incubate for about 23 days. When the nest is unattended for a prolonged period of time, the adults cover the nest with nesting material to protect it. Both parents feed the young and may carry them around on their backs, even while swimming underwater. Soon after hatching, the young can swim on their own.

Feeding habits

Insects, fish, and other aquatic creatures make up the bulk of the Pied-billed Grebe’s diet. The birds’ heavy bills are adapted to crushing large crustaceans, but Pied-billed Grebes are also opportunistic feeders, preying on a wide variety of aquatic creatures including fish. Like other grebes, Pied-billed Grebes will eat and feed their own feathers to their young. It is thought that these feathers help them regurgitate bones and other non-digestible parts of their diet.

Conservation

This species has a large range, with an estimated global Extent of Occurrence of 21,000,000 km². It has a large global population estimated to be 110,000-130,000 individuals (Wetlands International 2002). Global population trends have not been quantified, but the species is not believed to approach the thresholds for the population decline criterion of the IUCN Red List (i.e. declining more than 30% in ten years or three generations). For these reasons, the species is evaluated as Least Concern.

Migration

Migratory, dispersive, and sedentary. Breeding birds from much of central, north, and north-east North America migrate south for winter, apparently chiefly to south USA and Mexico, where overlap largely sedentary nesting population. Autumn passage begins August, with main body of migrants moving over protracted period September-November. Return movements begin March; re-occupation of breeding waters dependent on thaw, mostly April and early May.

Distribution map