Common Name: Bonin Grosbeak
Scientific Name: Chaunoproctus ferreorostris
Size: 8.25 inches (18-19 cm)
Habitat: Asia; Japan. Nothing is known of its ecology apart from Kittlitz's description, "this bird lives on Bonin-sima, alone or in pairs, in the forest near the coast. It is not common but likes to hide, although of a phlegmatic nature and not shy. Usually it is seen running on the ground, only seldom high in the trees."
Status: Extinct. Global Population: 0. The Bonin Grosbeak was discovered by the Beechey Pacific expedition, which collected 2 specimens on Chichi-jima in 1827. The following year, Kittlitz took several more specimens, but he only gave the locality "as" "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 whalers, settlement was begun in 1830. When the Rodgers-Ringgold North Pacific Exploring and Surveying Expedition called at Chichi-jima in 1854, naturalist William Stimpson 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 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. The Bonin Grosbeak probably succumbed soon after 1830 to habitat destruction (deforestation) and predation by the introduced mammals.
Diet: Fruits and flower buds, picked up from the ground or low shrubs.
Breeding: Male had red markings on the crown and throat; females do not have the markings. Breeding and nesting is assumed to be similar to other Grosbeak species. The nest consisted of a loose, open cup of twigs, plant stems, rootlets, and pine needles, lined with hair, string, and some plant materials. The nest is placed in outer branches of a small tree or shrub and often near a stream. 2-5 eggs are laid,
Cool Facts: Chaunoproctus ferreorostris is only known from specimens collected in 1827 and 1828 on Chichi-jima, Ogasawara-shoto (Peel Island, Bonin), Japan.