The Rapa fruit dove (''Ptilinopus huttoni'') is a species of bird in the family

Columbidae 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 ...

, which includes pigeons and doves. It is endemic to the island of

Rapa Iti Rapa, also called Rapa Iti, or "Little Rapa", to distinguish it from Easter Island, whose Polynesian name is Rapa Nui, is the largest and only inhabited island of the Bass Islands in French Polynesia. An older name for the island is Oparo. The ...

French Polynesia )Territorial motto: ( en, "Great Tahiti of the Golden Haze") , anthem = , song_type = Regional anthem , song = " Ia Ora 'O Tahiti Nui" , image_map = French Polynesia on the globe (French Polynesia centered).svg , map_alt = Location of Frenc ...

. The species was classified as Critically Endangered by 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 ...

in 2018 because of its small population and predicted continued decline. The Rapa fruit dove primarily feeds on fleshy fruit. Its

natural habitat In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...

is subtropical or tropical moist lowland forests and it has an extent of 30 km2. It is threatened by habitat loss due to deforestation and

invasive species An invasive species otherwise known as an alien is an introduced organism that becomes overpopulated and harms its new environment. Although most introduced species are neutral or beneficial with respect to other species, invasive species ad ...

. Effective land protection and management could increase the quality of habitat for the species. Additional research into population dynamics and the impact of threats to the species can give a better understanding of the conservation practices needed.

Description and range

The Rapa fruit dove is approximately 31

centimeters 330px, Different lengths as in respect to the Electromagnetic spectrum, measured by the Metre and its deriveds scales. The Microwave are in-between 1 meter to 1 millimeter. A centimetre (international spelling) or centimeter (American spellin ...

tall, making it a medium-sized dove. It is a colorful bird, with mostly green plumage, especially on its wings. Its foreparts (head, neck, chest, upper back) have blue-gray plumage. It has a yellow lower belly with a rose-purple band below its chest feathers. A distinguishing feature of the Rapa fruit dove is its bright pink crown, located on the face between the eyes. This species is endemic to the small island of

in the

Austral Islands The Austral Islands (french: Îles Australes, officially ''Archipel des Australes;'' ty, Tuha'a Pae) are the southernmost group of islands in French Polynesia, an overseas country of the French Republic in the South Pacific. Geographically, ...

and has an estimated extent of 30 km2. The population was estimated at 160 individuals in 2017, with all individuals in one subpopulation. Surveys carried out in 1989-1990 found a population of approximately 274, resulting in a 42% decline in population between the two surveys.

Ecology

The Rapa fruit dove lives in the remaining undisturbed forest fragments on the island and prefers an elevation between 40 – 450 meters. Rapa Iti has a tropical climate and the dove can be found in the moist lowland forests. They prefer the most wooded areas but can occasionally be found in the

Caribbean pine The Caribbean pine (''Pinus caribaea'') is a hard pine species native to Central America and the northern West Indies (in Cuba, the Bahamas, and the Turks and Caicos Islands). It belongs to subsection '' Australes'' in subgenus ''Pinus''. It inha ...

plantations. As indicated by their name, the Rapa fruit dove primarily feeds on fleshy fruit from the various trees on the island, as well as nectar from some flowers. There are many productive native berry trees on Rapa Iti to sustain the dove. While the strawberry guava is an invasive species and a cause for habitat decline, it is possible that it is also a source of food for the dove. They eat while perched in the tree and pick or reach for the fruit. Since they are heavier than some other fruit doves, the Rapa fruit dove does not move out to the end of the branches, and instead must perform many contortions to reach the fruit.

Conservation threats to habitat

The Rapa fruit dove's decreasing population size is caused by habitat loss. It lives in the forests of Rapa Iti, but very little of the island's original native forests remain. The destruction of the habitat was caused by logging, fires, and an increased need for grazing land for cattle and goats. The quality of the remaining habitat has diminished since the introduction of the invasive

strawberry guava ''Psidium cattleyanum (World Plants : Psidium cattleianum)'', commonly known as Cattley guava, strawberry guava or cherry guava, is a small tree (2–6 m tall) in the Myrtaceae (myrtle) family. The species is named in honour of English hor ...

from

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southe ...

. When left unchecked, the strawberry guava can grow uncontrollably in dense thickets and wreak havoc on ecosystems, choking out native species that the fruit dove relies on. Other invasive species, like

feral cat A feral cat or a stray cat is an unowned domestic cat (''Felis catus'') that lives outdoors and avoids human contact: it does not allow itself to be handled or touched, and usually remains hidden from humans. Feral cats may breed over dozens ...

s, predate on the fruit doves and have been a factor in their decline.

Use and trade

Historically, the Rapa fruit dove was hunted for food by the indigenous Polynesians. But an improvement in the standard of living on the island had ceased the hunting of the doves. Currently, they are not used for human benefit.

Conservation action in place

While there are no plans for conservation efforts to directly increase the population of the Rapa fruit dove, the necessity of habitat conservation and restoration has recently become recognized on the island. In 2017, a project began with the goal of restoring the forests, controlling the growth of the strawberry guava, and controlling the populations of grazing animals.

Conservation/research needed

Additional conservation efforts are needed to protect the Rapa fruit dove and the rest of the biodiversity on Rapa Iti. Ecological impacts due to humans are the main cause of declines and extinctions of birds in the Polynesian islands, especially Rapa Iti. More land needs to be effectively protected and managed to decrease grazing pressures and exclude fires from upland areas. There also needs to be increased control of invasive species populations. To directly increase the population of the fruit dove, an introduction to another island to establish a second population is recommended after the introduced mammals are eradicated from the islands. There is also the option of establishing a captive population of fruit doves as a precaution. Education and awareness are needed for the local community to gain their support for creating protected land areas. Further research into the actual impacts of the threats to the Rapa fruit dove is needed. It is unknown how feral cats are affecting the population of the fruit dove, and if its predation is a serious problem for their survival. It is also unclear how the Rapa fruit dove uses the strawberry guava, if at all. Additional research into these factors can give a better understanding of the population trends of the fruit dove and help guide conservation practices on the island.

References

{{Taxonbar, from=Q1274866 Rimatara reed warbler Birds of the Austral Islands Rimatara reed warbler Taxonomy articles created by Polbot Endemic fauna of French Polynesia Taxa named by Otto Finsch