Bonin Grosbeak

Bonin Grosbeak ( Chaunoproctus ferreorostris )

The Bonin Grosbeak or Bonin Finch ( Chaunoproctus ferreorostris ) is an extinct Fink, the only species in the genus Chaunoproctus. He belongs to the various Vogeltaxa, known colloquially as grosbeak, but are not closely related to the grosbeaks in the strict sense.

Description

It reached a length of 20 cm. In the male forehead, eye-streak, cheeks, throat and upper chest were orange. The lower chest was broad and walked toward the abdomen into whitish on. The rest of the plumage was olive brown with dark brown stripes on its back. Beak, feet and legs were probably black brown. The females were generally medium brown, had a yellowish forehead and flank feathers had dark brown tips. Contemporary pictures show considerable differences, particularly in the males. Whether these were due to seasonal variations, or whether several subspecies or even species existed, could only be determined after complete examination of the existing material.

Lifestyle and food

He was a reclusive, but not shy bird and was usually seen singly or in pairs. His diet consisted of fruits and buds, which he aufpickte primarily from the ground or low shrubs. He was rarely observed perching on trees, was apparently quite sluggish and flew only reluctantly. His singing consisted of soft, pure and high notes, sometimes elongated, sometimes individually and sometimes in quick succession.

Dissemination

He was only found on Chichi -jima ( bonuses Islands). While reports that he seemed on Haha -jima, almost certainly are wrong, he could have lived on Anijima and Ototojima. However, Chichi -jima is the only place where this bird was observed.

Extinction

The Bonin Grosbeak was discovered on Captain Beechey's Pacific expedition collected two specimens in 1827 on Chichi -jima. The following year, Heinrich von Kittlitz imposed several additional copies. As a reference, however, he was only Boninsima ( Ogasawara Islands). After two absorbed by Beechey shipwrecked sailors reported that the island would make a good stopover for whaling ships, began in 1830 the settlement. When the North Pacific Exploring Expedition of Rodgers - Ringgold visited 1854 Chichi -jima, the naturalist William Stimpson could not demonstrate any single bird more. What he found were rats, feral goats, sheep, dogs and cats, and pigs, which were already present since 1828 ( and which have been left behind by Beechey as provisions for future Schiffbrüchtige on the island). Just like the Bonin Erddrossel succumbed to the Bonin Grosbeak soon after 1830 due to habitat destruction and the looting by introduced mammals. In 1889 settlers had the bird collector Holst AP reported that some birds are said to have survived until the early 1880s on Haha -jima. However, this was never confirmed, especially since this species was not detected in 1853 during the visit of the officer Matthew Perry in 1854 on Haha -jima. His sedentary habits made ​​it largely unlikely that it occurred on islands outside the Chichi -jima Island group.

Of the specimens that were once collected, there are still 10 in museum collections.