The plumage was general glossy black with yellow feather tufts on the maxillaries, beneath the wings and the undertail coverts.

It was endemic to the montane forests of the Hawaiian islands of Molokai, Maui, and Lanai.

In 1915, Munro tried to verify reports of eventual sightings but he never found live individuals again.

[4] In 1902, Henshaw reported seeing a bird matching the appearance of Bishop's O'o in the Olinda region.

A spat of sightings of a bird with field marks and calls matching Bishop's O'o was reported in the 1980's from the Ko'olau Nature Reserve, most notably by Stephen R. Sabo in 1981.