The Bonin grosbeak or Bonin Islands grosbeak (''Carpodacus ferreorostris'') is an

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 ...

finch The true finches are small to medium-sized passerine birds in the family Fringillidae. Finches have stout conical bills adapted for eating seeds and nuts and often have colourful plumage. They occupy a great range of habitats where they are usua ...

. It is one of the diverse bird taxa that are vernacularly called "

grosbeak Grosbeak is a form taxon containing various species of seed-eating passerine birds with large beaks. Although they all belong to the superfamily Passeroidea, these birds are not part of a natural group but rather a polyphyletic assemblage of dist ...

s", but it is not closely related to the grosbeaks ''sensu stricto''. Many authorities place the species in the genus ''

Carpodacus The rosefinches are a genus, ''Carpodacus'', of passerine birds in the finch family Fringillidae. Most are called "rosefinches" and as the word implies, have various shades of red in their plumage. The common rosefinch is frequently called the " ...

'', but some place it in its own genus, ''Chaunoproctus''. A 2013 genetic analysis found it to be a relatively basal member of the group, more derived than the

common rosefinch The common rosefinch (''Carpodacus erythrinus'') or scarlet rosefinch is the most widespread and common rosefinch of Asia and Europe. Taxonomy In a molecular phylogenetic study of the finch family published in 2012, Zuccon and colleagues found t ...

, but with no close relatives, with an estimated divergence time from other members of the group around 12.5 million years ago.

Behaviour

It was a retiring although not shy bird, and was usually found singly or in pairs. It fed on fruits and buds which were primarily picked up from the ground or low shrubs; it rarely was observed to perch in trees, being apparently rather phlegmatic and somewhat reluctant to fly. Only one kind of vocalization has been described: a soft, pure and high note, sometimes short, sometimes drawn out; sometimes given singly, sometimes in a short series.

Habitat

It was found only on

Chichi-jima , formerly known as Peel Island, is the largest island in the Ogasawara Islands, Ogasawara archipelago. Chichijima is about north of Iwo Jima. The island is within the political boundaries of Ogasawara, Tokyo, Ogasawara Village, Ogasawara Subpref ...

in the

Ogasawara Islands The Bonin Islands, also known as the , are an archipelago of over 30 subtropical and tropical islands, some directly south of Tokyo, Japan and northwest of Guam. The name "Bonin Islands" comes from the Japanese word ''bunin'' (an archaic readi ...

. While reports that it was also found on

Haha-jima , native_name_link = , image_caption = Map of the Hahajima Rettō (Imōtojima is mislabeled as Tori-shima) , image_size = , pushpin_map = Japan complete , pushpin_label = Hahajima , pushpin_label_position = , pushp ...

are almost certainly erroneous, it might have occurred on Anijima and Otōtojima. Chichi-jima is the only place, however, where the bird was observed. Several specimens were taken; some 10 remain at present. Contemporary illustrations show considerable differences, especially in males. Whether these are due to seasonal variation or whether several subspecies or even species existed could only be determined by a thorough review of the available material.

Extinction

The Bonin grosbeak was discovered by the Beechey Pacific expedition, which collected two specimens on Chichi-jima in 1827. The following year, Kittlitz took several more specimens, but he only gave the locality "Boninsima" (="Bonin-shima": Ogasawara Islands). Following the report of two shipwrecked sailors, picked up by Beechey, that the island would make a good stopover station for

whaler A whaler or whaling ship is a specialized vessel, designed or adapted for whaling: the catching or processing of whales. Terminology The term ''whaler'' is mostly historic. A handful of nations continue with industrial whaling, and one, Japa ...

s, settlement was begun in 1830. When the

Rodgers Rodgers is a patronymic surname of Old English origin derived from the Norman personal name "Roger", with the addition of the genitive suffix "-s" and meaning “son of Roger.” The intrusive “d” in Rodgers is either a Welsh or Scottish addi ...

- Ringgold

North Pacific Exploring and Surveying Expedition The North Pacific Exploring and Surveying Expedition, also known as the Rodgers-Ringgold Expedition was a United States scientific and exploring project from 1853 to 1856. Commander Cadwalader Ringgold (1802–1867) led the expedition until ...

called at Chichi-jima in 1854, naturalist

William Stimpson William Stimpson (February 14, 1832 – May 26, 1872) was a noted American scientist. He was interested particularly in marine biology. Stimpson became an important early contributor to the work of the Smithsonian Institution and later, direc ...

could not find the birds. What he did find, however, were rats and feral goats, sheep, dogs and cats, in addition to the pigs that were already present in 1828 (and which might have been left there by Beechey to provision future castaways). Just like the

Bonin thrush The Bonin thrush (''Zoothera terrestris''), also known as Kittlitz's thrush or the Bonin Islands thrush, is an extinct species of Asian thrush. It is sometimes separated as the only species of the genus ''Cichlopasser''. The only place where thi ...

, the Bonin grosbeak probably succumbed soon after 1830 to habitat destruction and predation by the introduced mammals. The collector A. P. Holst was told by settlers on Chichi-jima in 1889 that some birds had persisted on Haha-jima until the early 1880s. However, given that the species was not reported from there neither during the 1853 visit of the first

Perry Perry, also known as pear cider, is an alcoholic beverage made from fermented pears, traditionally the perry pear. It has been common for centuries in England, particularly in Gloucestershire, Herefordshire, and Worcestershire. It is also made ...

mission to

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...

nor in 1854, this seems either erroneous or a misunderstanding for some other island in the Chichi-jima group. The sedentary habits of the Bonin grosbeak make it unlikely that it was present anywhere outside the ''Chichijima Rettō''.

Behaviour

Habitat

Extinction

References

Further reading