Threskiornithidae Temporal range: | |
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Scarlet ibis | |
Scientific classification ![]() | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Aves |
Order: | Pelecaniformes |
Suborder: | Ardei |
Family: | Threskiornithidae Poche, 1904 [1] [2] |
Subfamilies | |
The family Threskiornithidae includes 36 species of large wading birds. The family has been traditionally classified into two subfamilies, the ibises and the spoonbills ; however recent genetic studies have cast doubt on this arrangement, and have found the spoonbills to be nested within the Old World ibises, and the New World ibises as an early offshoot.
The family Threskiornithidae was formerly known as Plataleidae. The spoonbills and ibises were once thought to be related to other groups of long-legged wading birds in the order Ciconiiformes. A recent study found that they are members of the order Pelecaniformes. [4] In response to these findings, the International Ornithological Congress (IOC) recently[ when? ] reclassified Threskiornithidae and their sister taxa Ardeidae under the order Pelecaniformes instead of the previous order of Ciconiiformes. [5] Whether the two subfamilies are reciprocally monophyletic is an open question. The South American Checklist Committee's entry for the Threskiornithidae includes the following comment "Two subfamilies are traditionally (e.g., Matheu & del Hoyo 1992) recognized: Threskiornithinae for ibises and Plataleinae for spoonbills; because the main distinction has to do with bill shape, additional information, especially genetic, is required to recognize a major, deep split in the family." [6]
A study of mitochondrial DNA of the spoonbills plus the sacred and scarlet ibises found that the spoonbills formed a clade with old world genus Threskiornis , with Nipponia nippon and Eudocimus as progressively earlier offshoots and more distant relatives, and hence casts doubt on the arrangement of the family into ibis and spoonbill subfamilies. [7] Subsequent studies have supported these findings, the spoonbills forming a monophyletic clade within the "widespread" clade of ibises, including Plegadis and Threskiornis, while the "new World Endemic" clade is formed by the genera restricted to the Americas such as Eudocimus and Theristicus. [8]
Ibises are a rather old group, with well-preserved definitive fossils known as far back as the Eocene ( Rhynchaeites ), and potential members dating as far back as the Late Paleocene ( Dakotornis ). [9]
Members of the family have long, broad wings with 11 primary feathers and about 20 secondaries. They are strong fliers and, rather surprisingly, given their size and weight, very capable soarers. The body tends to be elongated, the neck more so, with rather long legs. The bill is also long, decurved in the case of the ibises, straight and distinctively flattened in the spoonbills. They are large birds, but mid-sized by the standards of their order, ranging from the dwarf olive ibis (Bostrychia bocagei), at 45 cm (18 in) and 450 g (0.99 lb), to the giant ibis (Thaumatibis gigantea), at 100 cm (39 in) and 4.2 kg (9.3 lb).
They are distributed almost worldwide, being found near almost any area of standing or slow-flowing fresh or brackish water. Ibises are also found in drier areas, including landfills.
The Llanos are notable in that these wetland plains support seven species of ibis in the one region. [10]
All ibises are diurnal; spending the day feeding on a wide range of invertebrates and small vertebrates: ibises by probing in soft earth or mud, spoonbills by swinging the bill from side to side in shallow water. At night, they roost in trees near water. They are gregarious, feeding, roosting, and flying together, often in formation.
Nesting is colonial in ibises, more often in small groups or singly in spoonbills, nearly always in trees overhanging water, but sometimes on islands or small islands in swamps. Generally, the female builds a large structure out of reeds and sticks brought by the male. Typical clutch size is two to five; hatching is asynchronic. Both sexes incubate in shifts, and after hatching feed the young by partial regurgitation. Two or three weeks after hatching, the young no longer need to be brooded continuously and may leave the nest, often forming creches but returning to be fed by the parents.
FAMILY: THRESKIORNITHIDAE
The following fossil genera are known: [9]
The ibis are a group of long-legged wading birds in the family Threskiornithidae that inhabit wetlands, forests and plains. "Ibis" derives from the Latin and Ancient Greek word for this group of birds. It also occurs in the scientific name of the western cattle egret mistakenly identified in 1757 as being the sacred ibis.
Spoonbills are a genus, Platalea, of large, long-legged wading birds. The spoonbills have a global distribution, being found on every continent except Antarctica. The genus name Platalea derives from Ancient Greek and means "broad", referring to the distinctive shape of the bill. Six species are recognised, which although usually placed in a single genus have sometimes been split into three genera.
The Pelecaniformes are an order of medium-sized and large waterbirds found worldwide. As traditionally—but erroneously—defined, they encompass all birds that have feet with all four toes webbed. Hence, they were formerly also known by such names as totipalmates or steganopodes. Most have a bare throat patch, and the nostrils have evolved into dysfunctional slits, forcing them to breathe through their mouths. They also have a pectinate nail on their longest toe. This is shaped like a comb and is used to brush out and separate their feathers. They feed on fish, squid, or similar marine life. Nesting is colonial, but individual birds are monogamous. The young are altricial, hatching from the egg helpless and naked in most. They lack a brood patch.
The Eurasian spoonbill, or common spoonbill, is a wading bird of the ibis and spoonbill family Threskiornithidae, native to Europe, Africa and Asia. The species is partially migratory with the more northerly breeding populations mostly migrating south for the winter.
The roseate spoonbill is a gregarious wading bird of the ibis and spoonbill family, Threskiornithidae. It is a resident breeder in both South and North America. The roseate spoonbill's pink color is diet-derived, consisting of the carotenoid pigment canthaxanthin, like the American flamingo.
The giant ibis is a wading bird of the ibis family, Threskiornithidae. It is confined to northern Cambodia, with a few birds surviving in extreme southern Laos and a recent sighting in Yok Đôn National Park, Vietnam. It is sometimes placed in the genus Thaumatibis.
The bird genus Pseudibis consists of three South-East Asian species in the ibis subfamily, Threskiornithinae.
The small bird genus Geronticus belongs to the ibis subfamily Threskiornithinae. Its name is derived from the Greek gérontos in reference to the bald head of these dark-plumaged birds; in English, they are called bald ibises.
The royal spoonbill also known as the black-billed spoonbill, occurs in intertidal flats and shallows of fresh and saltwater wetlands in Australia, New Zealand, Indonesia, Papua New Guinea, and the Solomon Islands. It has also been recorded as a vagrant in New Caledonia. The royal spoonbill lives in wetlands and feeds on crustaceans, fish and small insects by sweeping its bill from side to side. It always flies with its head extended. Widespread throughout its large range, the royal spoonbill is evaluated as Least Concern on the IUCN Red List of Threatened Species.
The yellow-billed spoonbill is a gregarious wading bird of the ibis and spoonbill family, Threskiornithidae. It is native to Australia, and is a vagrant to New Zealand, Lord Howe Island and Norfolk Island.
The green ibis, also known as the Cayenne ibis, is a wading bird in the ibis family Threskiornithidae. It is the only member of the genus Mesembrinibis.
The southern bald ibis is a large bird found in open grassland or semi-desert in the mountains of southern Africa. Taxonomically, it is most closely related to its counterpart in the northern regions of Africa, the waldrapp. As a species, it has a very restricted homerange, limited to the southern tips of South Africa in highland and mountainous regions.
Eudocimus is a genus of ibises, wading birds of the family Threskiornithidae. They occur in the warmer parts of the New World with representatives from the southern United States south through Central America, the West Indies, and South America.
The buff-necked ibis, also known as the white-throated ibis, is a fairly large ibis found widely in open habitats of eastern and northern South America. It formerly included the similar black-faced ibis as a subspecies, but that species is almost entirely restricted to colder parts of South America, has a buff lower chest, and lacks the contrasting large white wing-patches.
The sharp-tailed ibis is a species of ibis native to open wet savannas in parts of northern South America.
Theristicus is a genus of birds in the family Threskiornithidae. They are found in open, grassy habitats in South America. All have a long, decurved dark bill, relatively short reddish legs that do not extend beyond the tail in flight, and at least the back is grey.
Rhynchaeites is an extinct genus of wading bird, likely a stem-group ibis, from the Eocene. It is one of the oldest members of the Threskiornithidae known from fossil remains.
Vadaravis is an extinct genus of waterbird from the early Eocene period in North America. It contains a single species, Vadaravis brownae, named after American biologist Barbara Elaine Russell Brown. An almost complete skeleton of the bird, lacking the skull, was found in the sediments of the Green River Formation in Wyoming, United States. It was suggested to have possibly been a close relative of the Threskiornithidae family, which includes ibises and spoonbills.
Ardei is a suborder of order Pelecaniformes that include the families Ardeidae and Threskiornithidae. Traditionally the ardeids and threskiornithids were classified in the order Ciconiiformes along with Ciconiidae (storks), Phoenicopteridae (flamingos), Scopidae (hamerkop), Balaenicipitidae (shoebill), and even Cathartidae. However, there were some osteological studies that have questioned the monophyly of Ciconiiformes, suggesting that the ardeids and threskiornithids originated from early gruiforms, with the latter being a transitionary taxon to order Charadriiformes. The non-monophyletic nature of Ciconiiformes is supported by recent genomic studies that have found support for threskiornithids, ardeids, scopids and balaenicipitids being closely related to Pelecanidae (pelicans).