It was common in the subtropical forests of the island until the early twentieth century, when its decline began.

The causes of its extinction include the introduction of predators (such as the Polynesian rat, small Indian mongoose, and the domestic pig), mosquito-borne diseases, and habitat destruction.

The Kauaʻi ʻōʻō was very vocal, making hollow, erratic, flute-like calls.

The species became extinct from a large range of problems, including mosquito-transmitted diseases (which caused the species to retreat to higher ground, ultimately retreating to high-altitude montane forests in the Alakaʻi Wilderness Preserve), introduction of mammalian predators, and deforestation.

[10] Higher elevation forests lack tree cavities, so few, if any, nests could be made.

The final blows were two hurricanes, Iwa and Iniki, occurring within ten years of each other.

The male bird was last sighted in 1985, and the last sound recording was made in 1987 by David Boynton.

[14] However, it has a loud and distinctive call, and intensive surveys that occurred from 1989 to 2000 failed to find any.