The po'ouli was a small Hawaiian forest bird, a unique and ancient type of Hawaiian Honeycreeper, present on the islands for millions of years before its discovery on Maui in 1973 by a group of University of Hawaii students.

Discovered in inaccessible rain forest high on Maui's Haleakala volcano during the same year that Congress passed the Endangered Species Act , the bird was declared endangered shortly after its discovery. Despite that designation, a lack of interest, urgency and funding meant little was done to save the bird for almost two decades.

By the mid-1990s,the known population had dwindled to just three, living in different home ranges in Hawaii's inaccessible Hanwai Natural Area Reserve. State and federal agencies mounted a recovery effort that featured habitat management, an attempt at matchmaking in the wild, and, finally, captive breeding that ultimately ended with the last known bird's death.

A subsequent autopsy showed that the last po'ouli was very old and died of age-related causes. Efforts to find the other two birds in the wild failed. Though some biologists hold out hope that a few po'ouli still exist somewhere in the tangled rainforest they call home, even those optimists acknowledge that a small remnant population presents little hope for recovery.