Traditionally, a number of wading and terrestrial bird families that did not seem to belong to any other order were classified together as Gruiformes. These include 14 species of large cranes, about 145 species of smaller crakes and rails, as well as a variety of families comprising one to three species, such as the Heliornithidae, the limpkin, or the trumpeters. Other birds have been placed in this order more out of necessity to place them somewhere; this has caused the expanded Gruiformes to lack distinctive apomorphies. Recent studies indicate that these "odd Gruiformes" are if at all only loosely related to the cranes, rails, and relatives ("core Gruiformes").
|Crested crane, Balearica regulorum|
Some 5–10 living, see article text.
|Global distribution of the cranes and allies.|
There are only two suprafamilial clades (natural groups) among the birds traditionally classified as Gruiformes. Rails (Rallidae), flufftails (Sarothruridae), finfoots and sungrebe (Heliornithidae), adzebills (Aptornithidae), trumpeters (Psophiidae), limpkin (Aramidae), and cranes (Gruidae) compose the suborder Grues and are termed "core-Gruiformes" (Fain et al. 2007). These are the only true Gruiformes. The suborder Eurypygae includes the kagu (Rhynochetidae) and sunbittern (Eurypygidae). These are not even remotely related to Grues. The families of mesites or roatelos (Mesitornithidae), button-quails (Turnicidae), Australian plains-wanderer (Pedionomidae), seriemas (Cariamidae), and bustards (Otididae) each represent distinct and unrelated lineages. Many families known only from fossils have been assigned to the Gruiformes, e.g., Ergilornithidae, Phorusrhacidae, Messelornithidae, Eogruidae, Idiornithidae, Bathornithidae, to name just a few (see below). Though some of these are superficially 'crane-like' and the possibility that some may even be related to extant families traditionally included in the Gruiformes, there are no completely extinct families that can be confidently assigned to core-Gruiformes.
The traditional order Gruiformes was established by the influential German avian comparative anatomist Max Fürbringer (1888). Over the decades, many ornithologists suggested that members of the order were in fact more closely related to other groups (reviewed by Olson 1985, Sibley and Ahlquist 1990). For example, it was thought that sunbittern might be related to herons and that seriemas might be related to cuckoos. Olson and Steadman (1981) were first to correctly disband any of the traditional Gruiformes. They recognized that the Australian plains-wanderer (family Pedionomidae) was actually a member of the shorebirds (order Charadriiformes) based on skeletal characters. This was confirmed by Sibley and Ahlquist (1990) based on DNA–DNA hybridization and subsequently by Paton et al. (2003), Paton and Baker (2006) and Fain and Houde (2004, 2006). Sibley and Ahlquist furthermore removed button-quails (Turnicidae) from the Gruifomes based on large DNA–DNA hybridization distances to other supposed Gruiformes. However, it was not until the work of Paton et al. (2004) and Fain and Houde (2004, 2006) that the correct placement of buttonquails within the shorebirds (order Charadriiformes) was documented on the basis of phylogenetic analysis of multiple genetic loci. Using 12S ribosomal DNA sequences, Houde et al. (1997) were the first to present molecular genetic evidence of gruiform polyphyly, although apparently they were not convinced by it. However, on the basis of numerous additional sequence data, it has been shown decisively that the traditionally recognized Gruiformes consist of five to seven unrelated clades (Fain and Houde 2004, Ericson et al. 2006, Hackett et al. 2008).
Fain and Houde (2004) proposed that Neoaves are divisible into two clades, Metaves and Coronaves, although it has been suggested from the start that Metaves maybe paraphyletic (Fain and Houde 2004, Ericson et al. 2006, Hackett et al. 2008). Sunbittern, kagu, and mesites all group within Metaves but all the other lineages of "Gruiformes" group either with a collection of waterbirds or landbirds within Coronaves. This division has been upheld by the combined analysis of as many as 30 independent loci (Ericson et al. 2006, Hackett et al. 2008), but is dependent on the inclusion of one or two specific loci in the analyses. One locus, i.e., mitochondrial DNA, contradicts the strict monophyly of Coronaves (Morgan-Richards et al. 2008), but phylogeny reconstruction based on mitochondrial DNA is complicated by the fact that few families have been studied, the sequences are heavily saturated (with back mutations) at deep levels of divergence, and they are plagued by strong base composition bias.
The kagu and sunbittern are one another's closest relatives. It had been proposed (Cracraft 2001) that they and the recently extinct adzebills (family Aptornithidae) from New Zealand constitute a distinct Gondwanan lineage. However, sunbittern and kagu are believed to have diverged from one another long after the break-up of Gondwanaland and the adzebills are in fact members of the Grues (Houde et al. 1997, Houde 2009). The seriemas and bustards represent distinct lineages within neoavian waterbirds.
Rallidae based on the work by John Boyd.
When considered to be monophyletic, it was assumed that Gruiformes was among the more ancient of avian lineages. The divergence of "gruiforms" among "Metaves" and "Coronaves" is proposed to be the first divergence among Neoaves, far predating the Cretaceous–Paleogene extinction event c. 66 mya (Houde 2009). No unequivocal basal gruiforms are known from the fossil record. However, there are several genera that are not unequivocally assignable to the known families and that may occupy a more basal position:
Aramus paludigrus is an extinct species of limpkin, semi-aquatic birds related to cranes (order Gruiformes), which are similar. Aramus paludigrus was found in the famous Konzentrat-Lagerstätte of the Honda Group at La Venta, dating from the mid-Miocene period, in central Colombia.Ardeae
Ardeae is a clade that of birds that contains Eurypygimorphae and Aequornithes, named in 2014 by genome analysis. Initially members of Eurypygimorphae were originally classified in the obsolete group Metaves, and Aequornithes were classified as the sister taxon to Musophagiformes or Gruiformes.Balearica
The bird genus Balearica (also called the crowned cranes) contains two extant species in the crane family Gruidae: the black crowned crane (B. pavonina) and the grey crowned crane (B. regulorum).The species today occur only in Africa, south of the Sahara Desert, and are the only cranes that can nest in trees. This habitat is one reason the relatively small Balearica cranes are believed to closely resemble the ancestral members of the Gruidae.
Like all cranes, they eat insects, reptiles, and small mammals.Buff-spotted flufftail
The buff-spotted flufftail (Sarothrura elegans) is a species of bird in the family Sarothruridae.
It is found in Angola, Botswana, Burundi, Cameroon, Republic of the Congo, Democratic Republic of the Congo, Ivory Coast, Equatorial Guinea, Ethiopia, Gabon, Guinea, Kenya, Liberia, Malawi, Mozambique, Nigeria, Rwanda, Sierra Leone, Somalia, South Africa, South Sudan, Swaziland, Tanzania, Uganda, Zambia, and Zimbabwe.Eurypygiformes
Eurypygiformes is an order formed by the kagus, comprising two species in the family Rhynochetidae endemic to New Caledonia, and the sunbittern (Eurypyga helias) from the tropical regions of the Americas. Its closest relatives appear to be the tropicbirds of the tropical Atlantic, Indian, and Pacific oceans.Eurypygimorphae
Eurypygimorphae is a clade of birds that contains the orders Phaethontiformes (tropicbirds) and Eurypygiformes (kagu and sunbittern) recovered by genome analysis The relationship was first identified in 2013 based on their nuclear genes. Historically these birds were placed at different parts of the tree, with tropicbirds in Pelecaniformes and the kagu and sunbittern in Gruiformes, though in the last decade various genetic analysis had found in the almost obsolete clade Metaves of uncertain placement within that group. Their sister taxon is possibly Aequornithes.Gastornithiformes
Gastornithiformes were an extinct order of giant flightless fowl with fossils found in North America, Eurasia, and possibly Australia. Members of Gastornithidae were long considered to be a part of the order Gruiformes. However, the traditional concept of Gruiformes has since been shown to be an unnatural grouping. Beginning in the late 1980s and the first phylogenetic analysis of gastornithid relationships, consensus began to grow that they were close relatives of the lineage that includes waterfowl and screamers, the Anseriformes. Recognizing the apparent close relationship between gastornis and waterfowl, some researchers even classify them within the anseriform group itself. Others restrict the name Anseriformes only to the crown group formed by all modern species, and label the larger group including extinct relatives of anseriformes in the clade Anserimorphae (which this article and related pages have adopted). While the order is generally considered to be monotypic, a 2017 paper concerning the evolution and phylogeny of giant fowl by Worthy and colleagues have found phylogenetic support in finding the mihirungs (Dromornithidae) to be the sister taxon to the gastornis. The mihirungs are also another family of giant flightless birds that have been classified as anserimorphs either as crown anseriforms closely related to the screamers (Anhimidae) or the sister taxon to Anseriformes. Worthy et al. (2017) incorporated several new taxa and character traits into existing matrices of Galloanserae resulted in several of their phylogenies to support this grouping. The authors did note the bootstrap support is weakly supported and one of their phylogenies even found gastornithiforms to be stem galliforms instead. These too were also weakly supported as well. Below is a simplified phylogeny showing their one phylogeny supporting gastornithiforms as anserimorphs.Gruimorphae
Gruimorphae is a clade of birds that contains the orders Charadriiformes (plovers, gulls, and allies) and Gruiformes (cranes and rails) identified in 2014 by genome analysis. This grouping has had historical support, as various charadriiform families such as the families Pedionomidae and Turnicidae were classified as gruiforms. The relationship between these birds is due similar anatomical and behavioral characteristics. A morphological study went further to suggest that the gruiforms might be paraphyletic in respect to the shorebirds, with the rails being closely related to the buttonquails.Lesser moorhen
The lesser moorhen (Paragallinula angulata) is a species of bird in the family Rallidae. It is sometimes placed into the genus Gallinula. It is the only species in the genus Paragallinula.It is found in Angola, Benin, Botswana, Burkina Faso, Burundi, Cameroon, Central African Republic, Chad, Republic of the Congo, Democratic Republic of the Congo, Ivory Coast, Egypt, Equatorial Guinea, Ethiopia, Gabon, Gambia, Ghana, Kenya, Lesotho, Liberia, Malawi, Mali, Mozambique, Namibia, Niger, Nigeria, Oman, Rwanda, São Tomé and Príncipe, Senegal, Sierra Leone, Somalia, South Africa, Sudan, Swaziland, Tanzania, Togo, Uganda, Zambia, and Zimbabwe.List of Gruiformes by population
This is a list of Gruiformes species by global population. While numbers are estimates, they have been made by the experts in their fields. For more information on how these estimates were ascertained, see Wikipedia's articles on population biology and population ecology.
This list is not comprehensive, as not all Gruiformes have had their numbers quantified.Nkulengu rail
The Nkulengu rail (Himantornis haematopus) is a species of bird in the family Rallidae. It belongs to the monotypic genus Himantornis.For long, this singular rail was considered a member of a distinct subfamily Himantornithinae. This was based on the assumption that it was a sort of "living fossil", as it resembles other Gruiformes rather than other rails in many traits. But as it seems, the supposed plesiomorphies are actually atavistic or otherwise re-evolved traits in reaction to its African rainforest habitat. Its closest living relatives seem to be the Asian genera Amaurornis, Gallicrex, Megacrex, and the widespread African Aenigmatolimnas, with Megacrex and Himantornis representing ancient and ecologically quite similar lineages at the extreme ends of the group's distribution.It is found in Angola, Cameroon, Central African Republic, Republic of the Congo, Democratic Republic of the Congo, Ivory Coast, Equatorial Guinea, Gabon, Ghana, Guinea, Liberia, Nigeria, Sierra Leone, Togo, and Uganda.Red-chested flufftail
The red-chested flufftail (Sarothrura rufa) is a species of bird in the family Sarothruridae.
It is found in Angola, Botswana, Burundi, Cameroon, Central African Republic, Republic of the Congo, Democratic Republic of the Congo, Ethiopia, Gabon, Kenya, Liberia, Malawi, Mozambique, Namibia, Nigeria, Rwanda, Sierra Leone, South Africa, Swaziland, Tanzania, Togo, Uganda, Zambia, and Zimbabwe.Sarothruridae
Sarothruridae is a family of small- to medium-sized ground-living birds found in Madagascar and sub-Saharan Africa. The species in this family were once considered to sit with the larger rail family Rallidae. The family contains 2 genera.
Genus Sarothrura (flufftails; 9 species)
White-spotted flufftail, Sarothrura pulchra
Buff-spotted flufftail, Sarothrura elegans
Red-chested flufftail, Sarothrura rufa
Chestnut-headed flufftail, Sarothrura lugens
Streaky-breasted flufftail, Sarothrura boehmi
Striped flufftail, Sarothrura affinis
Madagascar flufftail, Sarothrura insularis
White-winged flufftail, Sarothrura ayresi
Slender-billed flufftail, Sarothrura watersi
Genus Canirallus (wood rails; 3 species)
Madagascan wood rail (Canirallus kioloides)
Tsingy wood rail (Canirallus beankaensis)
Grey-throated rail (Canirallus oculeus)Slaty-breasted rail
The slaty-breasted rail (Gallirallus striatus) is a species of rail found in the Indian Subcontinent and Southeast Asia.
Breeding has been recorded in July near Dehradun in the foothills of the Indian Himalayas.Spotted rail
The spotted rail (Pardirallus maculatus) is a species of bird in the family Rallidae.
It is found in Argentina, Belize, Bolivia, Brazil, Cayman Islands, Chile, Colombia, Costa Rica, Cuba, the Dominican Republic, Ecuador, El Salvador, French Guiana, Guyana, Haiti, Jamaica, Mexico, Panama, Paraguay, Peru, Suriname, Trinidad and Tobago, the United States, Uruguay, Venezuela, and possibly Honduras.
The spotted rail's natural habitat is a swamp.Striped crake
The striped crake (Aenigmatolimnas marginalis) is a species of bird in the family Rallidae. It is the only species in the genus Aenigmatolimnas, having formerly been included in Porzana or in the defunct genus Poliolimnas. Its precise relationships, however, are still enigmatic.Sunbittern
The sunbittern (Eurypyga helias) is a bittern-like bird of tropical regions of the Americas, and the sole member of the family Eurypygidae (sometimes spelled Eurypigidae) and genus Eurypyga. It is found in Central and South America, and has three subspecies. The sunbittern shows both morphological and molecular similarities with the kagu (Rhynochetos jubatus) of New Caledonia, indicating a gondwanic origin, both species being placed in the clade Eurypygiformes.White-naped crane
The white-naped crane (Antigone vipio) is a bird of the crane family. It is a large bird, 112–125 cm (44–49 in) long, approximately 130 cm (4.3 ft) tall and weighing about 5.6 kg (12 lb) with pinkish legs, grey and white striped neck, and a red face patch.
The white-naped crane breeds in northeastern Mongolia, northeastern China, and adjacent areas of southeastern Russia where a program at Khingan Nature Reserve raises eggs provided from U.S. zoos to bolster the species. Different groups of the birds migrate to winter near the Yangtze River, the DMZ in Korea and on Kyūshū in Japan. They also reach Kazakhstan and Taiwan. Only about 4,900 and 5,400 individuals remain in the wild.
Its diet consists mainly of insects, seeds, roots, plants and small animals.
Due to ongoing habitat loss and overhunting in some areas, the white-naped crane is evaluated as Vulnerable on the IUCN Red List of Threatened Species. It is listed on Appendix I and II of CITES.
In South Korea, It has been designated natural monument 203.
The white-naped crane was formerly placed in the genus Grus but a molecular phylogenetic study published in 2010 found that the genus, as then defined, was polyphyletic. In the resulting rearrangement to create monophyletic genera, four species, including the white-naped crane, were placed in the resurrected genus Antigone that had originally been erected by the German naturalist Ludwig Reichenbach in 1853.Yellow-breasted crake
The yellow-breasted crake (Porzana flaviventer) is a species of bird in the family Rallidae. It was formerly sometimes placed in the obsolete genus Poliolimnas or united with the Ocellated crake in Micropygia, and is now occasionally separated in a monotypic genus Hapalocrex. Phylogenetic analyses of mitochondrial DNA revealed that it is not a part of Porzana proper, and instead belongs within the Coturnicops–Laterallus clade. While its precise relationships are still insufficiently resolved, it is not closely related to Micropygia, and Stervander et al. (2019) suggested that it should be referred to as Laterallus flaviventer pending further data.It is found in most of Central and South America. Its natural habitat is swamps and marshes. This small rail has yellow legs, buff underparts, black barring on the flanks and a dark-streaked back, and a black crown.
15 living species in four genera