Bonin Grosbeak

It was found only on Chichi-jima in the Ogasawara Islands. While reports that it was also found on islands of the Haha-jima group (母島列島, known as "Baily Islands" to early Western explorers) are almost certainly erroneous, it might have occurred on Anijima and Otōtojima of the Chichi-jima group (父島列島, formerly "Beechey Islands"). Chichi-jima proper 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.

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.