| Pied-billed grebe | |
|---|---|
 | |
| P. p. podiceps, Summer plumage | |
_Cundinamarca.jpg) | |
| P. p. antarcticus, Colombia | |
Scientific classification | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Aves |
| Order: | Podicipediformes |
| Family: | Podicipedidae |
| Genus: | Podilymbus |
| Species: | P. podiceps |
| Binomial name | |
| Podilymbus podiceps | |
 | |
| Approximate distribution map Breeding Year-round Nonbreeding | |
| Synonyms | |
Thepied-billed grebe (Podilymbus podiceps) is aspecies of thegrebe family of water birds primarily found in ponds throughout theAmericas.[2]
The pied-billed grebe was described byCarl Linnaeus in the10th edition of hisSystema Naturae in 1758 asColymbus podiceps.[3] The binomial name is derived fromLatinPodilymbus, acontraction ofpodicipes ("feet at the buttocks", frompodici-, "rump-" +pes, "foot")—the origin of the name of the grebeorder—andAncient Greekkolymbos, "diver", andpodiceps, "rump-headed", frompodici- +Neo-Latinceps.[4]
Other names of this grebe includeAmerican dabchick,rail,dabchick,Carolina grebe,devil-diver,dive-dapper,dipper,hell-diver,pied-billed dabchick,pied-bill,thick-billed grebe, andwater witch.[5][6]
Since theextinction of theAtitlán grebe (Podilymbus gigas), the pied-billed grebe has become the sole extant member of thegenusPodilymbus.[7] Outside its own genus, the closest relatives of the pied-billed grebe are the small grebes of the genusTachybaptus.[8]
Pied-billed grebes are small, stocky, and short-necked. They are 31–38 cm (12–15 in) in length, with a wingspan of 45–62 cm (18–24 in) and weigh 253–568 g (8.9–20.0 oz).[10] They are mainly brown, with a darker crown and back.[11] Their brown color serves ascamouflage in the marshes they live in.[12] They do not have white visible under their wings when flying, like other grebes.[13] Their undertail is white[11] and they have a short, blunt chicken-like bill that is a light grey color,[2][11] which in summer is encircled by a broad black band (hence the name). In the summer, its throat is black.[2] There is nosexual dimorphism.[13] Juveniles have black and white stripes and look more like winter adults.[2] This grebe does not havewebbed feet. Its toes havelobes that come out of the side of each toe. These lobes allow for easy paddling.[2] When flying, the feet appear behind the body due to the feet's placement in the far back of the body.[11] Because of the feet placement, they are not able to walk on land.[14]
These grebes may be confused with theleast grebe, although that species is much smaller and has a thinner bill. Other similarly sized grebes are very distinct in plumage, i.e. theeared grebe andhorned grebe. Both species bear much more colorful breeding plumage, with rufous sides, golden crests along the side of the head against contrasting slaty color (also a rufous neck in the horned); while in winter, both the eared and horned grebes are pied with slaty and cream color and have red eyes. Because of the pied-billed grebe's duck-like habits, some inexperienced observers may confuse it with a duck.[15] However, pied-billed grebes have a very different bill shape (shorter, pointed at the tip, and flattened along the sides), as well as being shorter-necked and shorter-bodied than a duck. Also, unlike ducks, the closest living relatives of the grebe family areflamingos.[16]
Its call is unique, loud and sounds like a "whoopingkuk-kuk-cow-cow-cow-cowp-cowp."[17] Its call is similar to theyellow-billed cuckoo.[12]
They are most commonly found throughout North andCentral America, theCaribbean, and South America year round. During the summer breeding season, they are most prevalent in central, northern and northeasternCanada.[2] If they live in an area where the water freezes in the winter they will migrate. Migrating birds generally meet with year-round birds in September and October.[18] They migrate at night.[2] Most migratory birds leave in March or April.[18] They make occasional appearances in Europe andHawaii.[2] In theUnited Kingdom, pied-billed grebe visits have numbered 45 sightings as of 2019, appearing generally in October to January.[19] One bird in England bred with alittle grebe, producinghybrid young.[20] It is the only grebe on record to have visited theGalapagos Islands.[21]
Pied-billed grebes are found infreshwaterwetlands withemergent vegetation, such ascattails.[17] They are occasionally found insalt water. When breeding they are found in emergent vegetation near open water, and in the winter they are primarily found in open water due to the lack of nests to maintain. They may live near rivers, but prefer still water. They may be found in higher elevations when migrating.[18] They will breed in restored and man-made wetlands.[18]
Pied-billed grebes live approximately 10–12 years.[13]
Pied-billed grebes rarely fly. They make a slow dive frequently, especially when in danger, diving to about 20 ft (6.1 m) or less.[2][13] They dive for about 30 seconds and may move to a more secluded area of the water, allowing only the head to be visible to watch the danger dissipate.[13] This frequency in diving has earned them the description of being reclusive or shy in nature.[17] It has also earned them nicknames like "hell-diver."[5] Pied-billed grebes can trap air in their feathers, which controls their buoyancy.[22] They rarely spend time in flocks.[18] Theircourtship include calling and sometimes duets.[18] Males will show territorial behaviour if another male is at the edge of his territory. They face each other and then turn their heads and bills up. Then they turn away and start calling. Then they turn back around to look at one another.[13]
The pied-billed grebe breeds in south-centralCanada, throughout the United States,Central America, theCaribbean, and temperateSouth America.[10] These grebes may lay up to two sets of eggs a year.[13] Their nests sit on top of the water, their eggs sitting in vegetation that resides in the water.[17] Grebes lay between three and ten bluish white smooth elliptical eggs with the female starting the incubation process.[2][13] They are incubated for around 23 days by both parents, with the female taking over incubation duties towards the end of that time period.[13][18] They will cover the nest with nesting material if they have to leave it for an extended period of time.[18]
Young grebes may leave the nest within one day of hatching. They aredowny at birth. Yellow skin is seen between thelore and top of the head.[13] They do not swim well and stay out of the water. They sleep on their parents' backs. Within four weeks they start swimming.[2] When alerted they will climb on the back of a parent grebe and eventually mature to dive under the water like their parents.[2][17] Both parents share the role of raising the young – both feeding and carrying them on their backs.[18] Sometimes the parents will dive underwater to get food with the chicks on their backs.[13]
Pied-billed grebes feed mainly on aquaticinvertebrates, and also on smallfish andamphibians (frogs,tadpoles). They dive to obtain food.[2] Their bills allow them to crushcrustaceans, likecrawfish.[2][18] They may also eat plants.[6] They have been shown to eat their own feathers, like other grebes, to aid in digestion (prevent injury from small bones).[23] They will also feed their feathers to their young.[18]
They are extremely sensitive to disturbances, especially by humans. While breeding, if scared, adults may abandon their nests without protecting the eggs. The waves fromboats can destroy the nests and their sounds easily frighten the birds.[12]
Pied-billed grebe feathers are thick and soft. Their feathers were formerly used as decorations on hats andearmuffs and they were hunted in the eastern United States, in the 19th century.[12][13]
The status of pied-billed grebes in theNortheastern United States is dire; they are declining inNew England. The reasons are unknown.[18] The states ofConnecticut andNew Hampshire have declared the pied-billed grebe asendangered. InNew Jersey[12] andMassachusetts, they have been declaredthreatened. InVermont they are of "special concern." InRhode Island they areextirpated.[13] Pied-billed grebes are protected under theMigratory Bird Treaty Act of 1918.
Habitat loss is the grebe's biggest threat. The draining, filling, and general destruction of wetlands causes a loss in their breeding habitats.[12] However, they are still common in the majority of their distribution areas.[18]
