Kauaʻi ʻōʻō

The Kauai oo, Moho braccatus, was a Hawaiian honeyeater of the family Mohoidae, a family that originated more than 15 to 20 million years ago during the Miocene and of which this species was the last surviving member. Among the smallest of the oo, it measured just over 20 centimeters long, with a black head, wings and tail, slaty brown upperparts, golden-yellow leg feathers, and was the only oo known to have yellow irises. It was endemic to the Hawaiian island of Kauai, living in densely forested canyons and eventually surviving only in the higher-elevation Alakai Wilderness Preserve, where its decline was driven by introduced predators such as rats, mongooses and pigs, mosquito-borne disease and deforestation, and accelerated by Hurricanes Iwa and Iniki. It was last seen in 1985 and last heard in 1987, was declared extinct by the IUCN in 2000 and formally delisted in October 2023, an extinction that marked the first loss of an entire bird family in over 500 years.