By Autumn Smith
Geographic Range
Pied-billed grebes breed on the Alaskan coasts, and throughout Canada and the United States. They also breed in some areas of the Caribbean, such as Bermuda and the West Indies and in South America to central Chile and southern Argentina (American Ornithologists' Union, 1998; McLaren, 1998).
Pied-billed grebes migrate with other birds from the northern United States and Canada where bodies of water tend to freeze to southern parts of North America and along South America and the Caribbean (Muller and Storer, 1999). (American Ornithologists' Union, 1998; McLaren, 1998)
Biogeographic Regions:
nearctic 
(native ); neotropical (native ).
Habitat
During the breeding season, pied-billed grebes reside in freshwater ponds or lakes to moderately brackish waters. They usually live in areas with emergent or aquatic vegetation which provides good nest site locations. In the winter season, they use the same type of habitat as long as the water is not frozen. (Muller and Storer, 1999)
These animals are found in the following types of habitat:
temperate ; terrestrial ; freshwater .
Aquatic Biomes:
lakes and ponds; rivers and streams; brackish water .
Wetlands: marsh .
Other:
agricultural ; riparian .
Physical Description
(8.91 to 19.99 oz; avg. 15.84 oz)
(12.01 to 15 in; avg. 13 in)
(6.3 in)
In breeding season, pied-billed grebes have dark brownish plumage on their upper parts and grayish plumage on the sides of their neck and flanks. They have a black patch on their throat with a whitish outline; the black extends to the malars. They have a conspicuous white ring around the eye. Their bill has a slight hook and is very distinct in breeding season when it has a bluish white color with a distinct black vertical bar. The belly and underwing are whitish as are the under tail-coverts (Godfrey, 1986).
The winter plumage tends to consist of a pale throat, and a fleshy colored bill with no black markings. Upper parts are similar to breeding plumage, however, the sides of the neck and flanks are reddish brown.
The only distinguishing characteristic of juvenile plumage is that the bill is a dull orange color and there are sometimes white markings on the side of the head. Sexes are alike (Muller and Storer, 1999).
Pied-billed grebes weigh 253 to 568 g, are 30.5 to 38.1 cm long and have a wingspan of 16 cm on average. (Godfrey, 1986; Muller and Storer, 1999)
Some key physical features:
endothermic ; bilateral symmetry .
Sexual dimorphism: sexes alike.
Reproduction
Pied-billed grebes breed once per year. Pairs in the southern part of the range may raise two broods during a single breeding season.
Pied-bill grebes begin breeding around April or May and continue through about October.
Like other grebes, P. podiceps is monogamous on a seasonal or multi-seasonal basis. However, unlike other grebes, it has no intricate courtship display. Courtship has five different stages: Advertising, the Pirouette Ceremony, Ripple Dive, Circle Display, and Triumph Ceremony.
Advertising marks the beginning of courtship, swimming around with sleek feathers and elongated neck allow the single bird to let birds of opposite sex take notice of his or her availability. In the pirouette ceremony, each bird approaches the other and then takes an upright posture and may give a greeting call followed by a series of head turning jerks. The Ripple Dance involves dives and races underwater to show the other bird his or her swimming prowess. The Circle Display is self explanatory and can be initiated by either sex; during the Circle Display the pair are several meters apart on the water surface. The Triumph Ceremony, which takes place after mates have been established, consists of each mate circling around the other in a stooped position. (Palmer, 1962)
Mating systems:
monogamous .
Pied-billed grebes first breed when they are one or two years old. Grebes breeding in the north raise one brood each summer. Some pairs breeding in the south may raise two broods in a summer. Pied-billed grebe nests float and are anchored to marsh vegetation in shallow waters. Both sexes gather soft, flexible, decomposed or fresh plants from the lake bottom to construct the nest. The nest itself resembles a bowl (Muller and Storer, 1999).
The eggs are oval in shape and are bluish white to greenish white and occasionally turquoise. Within two days, the eggs become white and then take on the nest stains and turn brown (Muller, 1995). The typical clutch size is between two and ten (Glover, 1953) with incubation between 23 and 27 days. The chicks are able to leave the nest within an hour of hatching, usually by climbing onto a parent's back. They become independent from their parents within 25 to 62 days.
The breeding season for pied-billed grebes begins in approximately April or May and continues through about October. (Ackerman and Platter-Reiger, 1979; Ehrlich, Dobkin, and Wheye, 1988; Glover, 1953; Muller and Storer, 1999; Muller, 1995)
Key reproductive features:
iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization ; oviparous .
Both male and female pied-billed grebes incubate the eggs. The chicks are precocial and can swim and dive immediately after hatching. However, parents continue to protect the chicks for several weeks, and often carry them on their backs. The parents feed the chicks from the time they hatch until they become independent, up to 10 weeks after hatching. (Ehrlich, Dobkin, and Wheye, 1988; MacVean, 1988; McAllister, 1963; Muller, 1995)
Parental investment:
precocial ; pre-fertilization (provisioning, protecting: female); pre-hatching/birth (protecting: male, female); pre-weaning/fledging (provisioning: male, female, protecting: male, female); pre-independence (provisioning: male, female, protecting: male, female).
Lifespan/Longevity
There is little information available on pied-billed grebes lifespans. However, grebes are thought to be long-lived birds. One wild pied-billed grebe is thought to have lived at least five years. (Storer, 1960)
Behavior
Pied-billed grebes, like all grebes, are excellent swimmers and divers. Their feet are placed far back on their body, giving them greater ability to rotate the tibiotarsus. This allows them to move their feet above, below, or level with the body underwater. Because their feet are placed far back on the body, pied-billed grebes are extremely awkward on land. (Townsends, 1924; Stolpe, 1935; Storer, 1960).
Like other grebes, pied-billed grebes need a long running start on the surface of the water while flapping their wings, in order to fly. Pied-billed grebes are strong fliers, but are not very maneuverable (Bent, 1919; Miller, 1942).
Pied-billed grebes are extremely territorial during the breeding season. Single males or pairs establish territories that they defend. The territory size for a breeding pair is highly variable, with the average size of 13,000 square meters. Pied-billed grebes are more social when not in breeding season. They are often observed chasing fish, playing together and diving for objects underwater (MacVean, 1988; Muller, 1995).
Most pied-billed grebes migrate with other birds from the northern United States and Canada, where bodies of water usually freeze in the winter. They migrate to southern parts of North America and along South America and the Caribbean. Some pairs may remain on their breeding territory through the winter if the water does not freeze over (Muller and Storer, 1999). (Bent, 1919; MacVean, 1988; Miller, 1942; Muller and Storer, 1999; Muller, 1995; Stolpe, 1935; Storer, 1960; Townsend, 1924)
Home Range
We do not have information on home range for this species at this time.
Key behaviors:
flies; natatorial ; diurnal ; motile ; migratory ; solitary ; territorial ; social .
Communication and Perception
Pied-billed grebes use vocalizations and very complex and varied visual displays to communicate in courtship and in territorial matters. During courtship, the male and female of a pair may vocalize in a duet. The songs of pied-billed grebes can vary from a series of calls that sound like "wup, whut, kuk" which continually increases to a "cow" followed by a high pitched "kuk" and low pitched "kow" (Deusing, 1939; Simons, 1969; Godfrey, 1986). (Deusing, 1939; Godfrey, 1986; Muller and Storer, 1999; Simmons, 1969)
Other communication keywords:
duets .
Food Habits
Pied-billed grebes feed on what is most readily available and is not too big for them to grip with their bill. Usually they eat small fish, crustaceans (in particular crayfish), and aquatic insects and their larvae. Some examples of potential food items include crayfish, beetles, minnows, leeches, sticklebacks, and sunfish.
Pied-billed grebes obtain water by dipping thier bill into the water, and then tipping their head back. (Ehrlich, Dobkin, and Wheye, 1988)
Primary Diet:
carnivore (piscivore , insectivore , eats non-insect arthropods).
Animal Foods:
fish; insects; terrestrial non-insect arthropods; terrestrial worms; aquatic crustaceans.
Predation
- glaucous-winged gulls (Larus glaucescens)
- great horned owls (Bubo virginianus)
- American coots (Fulica americana)
- bald eagles (Haliaeetus leucocephalus)
- peregrine falcons (Falco peregrinus)
- cottonmouths (Agkistrodon piscivorus)
- American alligators (Alligator mississippiensis)
- snapping turtles (Chelydra serpentina)
- Norway rats (Rattus norvegicus)
- raccoons (Procyon lotor)
- minks (Mustela)
Known predators of pied-billed grebes include glaucous-winged gulls, great horned owls, American coots, bald eagles, peregrine falcons, cottonmouths, American alligators, snapping turtles, Norway rats, raccoons and mink.
When threatened by a predator, pied-billed grebes may swim away or dive away and resurface hidden among vegetation with only their eyes and nostrils showing. Adult grebes may also flap their wings, fake injury, and vocalize to distract and lure predators away from their nest (Rockwell, 1910; Allen, 1914; Gabrilson, 1914; Wetmore, 1920; Miller, 1942) . They may also lunge at the predator to drive it away. Adults will sometimes carry threatened chicks on their back away from a predator. Chicks may hold onto their parent's tail with their bill and can even hold on while swimming under water for a long distance to escape predators. (Allen, 1914; Eifrig, 1915; Gabrielson, 1914; Miller, 1942; Peck, 1919; Rockwell, 1910; Wetmore, 1920)
Ecosystem Roles
Pied-billed grebes affect populations of their prey. They are also host to some internal and external parasites.
Economic Importance for Humans: Negative
Pied-billed grebes eat small fish which may impact populations of economically important fish.
Economic Importance for Humans: Positive
Pied-billed grebes are a focus of ecotourism and much research.
Ways that people benefit from these animals:
ecotourism ; research and education.
Conservation Status
IUCN Red List: [link]:
Least Concern.
US Migratory Bird Act: [link]:
Protected.
US Federal List: [link]:
No special status.
CITES: [link]:
No special status.
State of Michigan List: [link]:
No special status.
Degradation and destruction of their wetland habitat threaten populations of pied-billed grebes. They are also affected by poisoning from pesticides and other contaminants, such as DDE and PCB. Other sources of mortality include entanglement in fishing lines, accidental shooting when they are mistaken for ducks, and collision with man-made objects such as television towers.
Pied-billed grebes are protected by the US Migratory Bird Treaty Act, but are not listed on the US Federal List, or by CITES or the IUCN. (Muller and Storer, 1999)
Contributors
Kari Kirschbaum (editor), Animal Diversity Web Staff.
Autumn Smith (author), University of Arizona.
Todd McWhorter (editor), University of Arizona. Alaine Camfield (editor), Animal Diversity Web.
