The tooth-billed pigeon (''Didunculus strigirostris''), also known as the ''manumea'', is a large pigeon found only in

Samoa Samoa, officially the Independent State of Samoa; sm, Sāmoa, and until 1997 known as Western Samoa, is a Polynesian island country consisting of two main islands (Savai'i and Upolu); two smaller, inhabited islands (Manono Island, Manono an ...

. It is the only living

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

Didunculus The tooth-billed pigeons are the only genus (''Didunculus'') of the subfamily Didunculinae, in the pigeon and dove family, (Columbidae). It has no close living relatives, but it has been shown to be genetically close to the dodo, and the genus n ...

''. A related

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

species, the

Tongan tooth-billed pigeon The Tongan tooth-billed pigeon (''Didunculus placopedetes''), is an extinct species of pigeon that was endemic to Tonga that lived in the Quaternary period. A related species, the tooth-billed pigeon (''Didunculus strigirostris''), is the only kn ...

(''Didunculus placopedetes''), is only known from

subfossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in ...

remains in several archeological sites in

Tonga Tonga (, ; ), officially the Kingdom of Tonga ( to, Puleʻanga Fakatuʻi ʻo Tonga), is a Polynesian country and archipelago. The country has 171 islands – of which 45 are inhabited. Its total surface area is about , scattered over in ...

. The tooth-billed pigeon is the

national bird This is a list of national birds, including official birds of overseas territories and other states described as nations. Most species in the list are officially designated. Some species hold only an "unofficial" status. National birds See al ...

of Samoa and featured on the 20 '' tālā'' bills and the 50 ''sene'' pieces of the 2008/2011 series. Native only to Samoa's primary rainforest, it is considered to be endangered, with only a few hundred individuals thought to remain in existence.

Description

The tooth-billed pigeon is a medium-sized, approximately 31 cm long, dark

pigeon Columbidae () is a bird family consisting of doves and pigeons. It is the only family in the order Columbiformes. These are stout-bodied birds with short necks and short slender bills that in some species feature fleshy ceres. They primarily ...

with reddish feet and red bare skin around the eye. The underparts, head and neck are greyish with a slight blue-green iridescence, and the tail, wings-coverts and

tertials Flight feathers (''Pennae volatus'') are the long, stiff, asymmetrically shaped, but symmetrically paired pennaceous feathers on the wings or tail of a bird; those on the wings are called remiges (), singular remex (), while those on the tail ...

are rufous chestnut, while the remaining remiges are blackish. It has a large, curved, and hooked bright red

bill Bill(s) may refer to: Common meanings * Banknote, paper cash (especially in the United States) * Bill (law), a proposed law put before a legislature * Invoice, commercial document issued by a seller to a buyer * Bill, a bird or animal's beak Plac ...

with tooth-like projections on the lower mandible. Both sexes are similar, but the juvenile is duller with a browner head, with a black bill with only the base a pale orange. Behaviourally, it is unusual - perhaps unique - among members of Columbiformes in drinking by scooping water up in its bill, in the manner of the great majority of bird species, rather than sucking it up using the tongue as a straw.

Taxonomy and systematics

The species was probably found in October or November 1839, by the United States' Exploring Expedition under Commander Wilkes. The discovery of the bird was announced by

Hugh Edwin Strickland Hugh Edwin Strickland (2 March 1811 – 14 September 1853) was an English geologist, ornithologist, naturalist and systematist. Through the British Association, he proposed a series of rules for the nomenclature of organisms in zoology, known a ...

in September 1844 as being among the rarities obtained by Mr. Titian Peale, the naturalist of the expedition. The formal description was made by William Jardine (Ann. Nat. Hist. xvi. p. 175, plate 9), under the name of ''Gnathodon strigirostris'', although that genus name was already in use for a mollusc. It has no close living relative, but it has been shown to be genetically close to the

dodo The dodo (''Raphus cucullatus'') is an extinct flightless bird that was endemic to the island of Mauritius, which is east of Madagascar in the Indian Ocean. The dodo's closest genetic relative was the also-extinct Rodrigues solitaire. The ...

, and the genus name ''Didunculus'' means "little dodo". the English name of dodlet was suggested by Sir Richard Owen. The jaw and tongue structure, and the superficially

parrot Parrots, also known as psittacines (), are birds of the roughly 398 species in 92 genera comprising the order Psittaciformes (), found mostly in tropical and subtropical regions. The order is subdivided into three superfamilies: the Psittacoid ...

like bill have suggested a relationship to the parrots, but these features have arisen from its specialised diet rather than any real relationship. The following

cladogram A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to d ...

, from Shapiro and colleagues (2002), shows the tooth-billed pigeon as the basal member of the clade and closest relationships within Columbidae, a

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...

consisting of generally ground-dwelling island endemics of which the Dodo is the most prominent. A similar cladogram was published in 2007, differing only in the inverted placement of ''Goura'' and ''Didunculus'', as well as in the inclusion of the

pheasant pigeon The pheasant pigeon (''Otidiphaps nobilis'') is a species of large terrestrial pigeon. It is the only species of the monotypic genus ''Otidiphaps''. The pheasant pigeon is found in the primary rainforests of New Guinea and nearby islands. It rang ...

and the

thick-billed ground pigeon The thick-billed ground pigeon (''Trugon terrestris''), also known as the jungle pigeon or the slaty/grey ground pigeon, is a species of bird in the family Columbidae. It is monotypic within the genus ''Trugon''.del Hoyo, J. Elliott, A. & Sargat ...

at the base of the clade.

Distribution and habitat

The tooth-billed pigeon is confined to undisturbed forests of

in the

Pacific The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...

. Natural habitats for the tooth-billed pigeon in Samoa include the

Central Savai'i Rainforest Central is an adjective usually referring to being in the center of some place or (mathematical) object. Central may also refer to: Directions and generalised locations * Central Africa, a region in the centre of Africa continent, also known as ...

, Tafua Preserve, Fagaloa Bay – Uafato Tiavea Conservation Zone on

Upolu Island Upolu is an island in Samoa, formed by a massive basaltic shield volcano which rises from the seafloor of the western Pacific Ocean. The island is long and in area, making it the second largest of the Samoan Islands by area. With approximatel ...

, and Nu'ulua island. Little is known about the ecology and biology of the species but it is believed to feed on the fruits of ''

Dysoxylum ''Dysoxylum'' is a flowering plant genus of trees and shrubs from the mahogany family, Meliaceae. Botanical science has recorded about eighty species in this genus, growing widely across the regions of Malesia, the western Pacific ocean, Austra ...

'', a tree in the

mahogany Mahogany is a straight-grained, reddish-brown timber of three tropical hardwood species of the genus ''Swietenia'', indigenous to the AmericasBridgewater, Samuel (2012). ''A Natural History of Belize: Inside the Maya Forest''. Austin: Unive ...

family. Manuscripts from the 1800s suggest chicks are confined to the forest floor. However the location of nests (in a tree or on the ground) is still unconfirmed.

Status

Because of ongoing habitat loss, limited range, small population size, hunting and occasional cyclones as well as the likely impact of introduced species such as pigs, dogs, rats and cats, the tooth-billed pigeon is evaluated as critically endangered on the

IUCN Red List The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biol ...

of Threatened Species. Surveys suggest numbers are critical and that 70 to 380 individuals survive in the wild, and there is currently no captive population. No juveniles had been sighted during any recent surveys until the 2013 sighting of a single juvenile in the lowlands of Savaii during a survey of the Samoan Ministry of Natural Resources and the Environment. It is highly likely that chick mortality is high and the observed population are an aged population of adult birds. Actions to save this species will likely require conservation education to reduce hunting risk, and knowledge of the biology of the population and the reasons behind the current decline. Population control for rats and cats is likely to be critical, as is continuing deforestation and disappearance of old-growth forests. In 2020 the bird was both heard and seen during a survey of forests on Savai'i.

References

External links

BirdLife Species Factsheet

* ttps://pigeonpedia.com/tooth-billed-pigeon/ Tooth Billed Pigeon: Breed Guide - Pigeonpedia.com {{Taxonbar, from=Q144053

tooth-billed pigeon The tooth-billed pigeon (''Didunculus strigirostris''), also known as the ''manumea'', is a large pigeon found only in Samoa. It is the only living species of genus '' Didunculus''. A related extinct species, the Tongan tooth-billed pigeon (''D ...

Birds of Samoa Endemic fauna of Samoa