The Po’ouli History and Recovery Efforts
The history of this cryptic Hawaiian honeycreeper is a brief and unfortunate one. In 1973, a small group of researchers from the University of Hawaii made a surprising discovery in the remote mountains of Haleakala. They discovered a new species of bird that was not known even to historical collectors or the Hawaiian oral tradition. This bird was eventually given the name Po'ouli, which means "black-faced" in Hawaiian. This was a major addition to the avifauna of the Hawaiian Islands, as the po'ouli, because of its uniqueness, was placed into a monotypic genus, ( Casey and Jacobi 1974). Because the area of discovery was frequented so rarely, not
much more was learned about the po'ouli for another next decade. A 1980 survey of the birds of the Hawaiian Islands estimated the population of the po'ouli at 140 birds. This estimate was based on very few sightings with a very large margin of error (Scott et al. 1986). Anecdotal data from observations in the late 1970s to mid 1980s do suggest a decline in the population of the species. This closely correlates with a large increase in the amount of damage that feral pigs were doing to the understory of the forest within the po’ouli habitat at this time (Mountainspring et al. 1990).
In the 1980s, greater attention to the plight of Hawaiian forest birds and their decline helped generate more research into the biology of the po'ouli. From dietary analyses, it was determined that the po'ouli was unique in the existing Hawaiian honeycreeper lineage in relying predominately on native land snails for food (Baldwin and Casey 1983). In 1986, the first two nests of the po'ouli were found high in native ohia trees and remain the only ones ever discovered. These nests were studied intensively and one fledgling was reared from the second attempt (Kepler et al. 1996). Investigations into the ecology and life history of the po'ouli seemed to indicate a bird that relied on pristine forest and was declining rapidly (Mountainspring et al. 1990).
Late on in 1986, the first step in the conservation of Maui's endangered forest bird community was taken when a 3,000-hectare portion of the Koolau Forest Reserve was designated as the Hanawi Natural Area Reserve. This forest contained some of the highest densities of native birds on Maui and included the only habitat area where the po'ouli was found. In the early 1990s, the upper forests of Hanawi were fenced to exclude feral pigs and allow the understory to regenerate.
Due to a lack of funds from state or federal research groups, little research was done in the Hanawi area from the late1980s to the mid 1990s, thus the population status of the po'ouli during this time was little known. A survey in 1988 did reveal that the species had disappeared from the westernmost portion of its range possibly due to pig activity (Engilis 1990). New searches for many of the critically endangered forest birds in Hawaii were again initiated in 1994. Searches detected fewer than ten po'ouli remaining in Hanawi, and then by 1997, only three of these birds could be found. These three po'ouli were located in three geographically separate home ranges across the Hanawi Natural Area Reserve and its vicinity, and would thus, not naturally come into contact with one another (Baker 2001, Reynolds and Snetsinger 2001).
The three known po’ouli were all captured and banded in 1997 and 1998. This allowed researchers to determine that they were indeed seeing the same individuals in each area. In the late 1990s, many more
searches were carried out in the areas of the remaining po'ouli, in the hopes that more birds would be discovered. Despite many hours in the field, no more birds have ever been seen. A new decision had to be made about the future of the po'ouli and how to respond to the extremely low numbers.
In 1998, experts around the world were consulted about the po'ouli and how to implement a recovery plan to save it. Many of the experts recommended that increased management of the habitat was the most important aspect of a recovery strategy. During this time, grids were
laid out in each of the remaining home ranges and a predator control program was initiated.