Pacific Islands Fish and Wildlife Office
Pacific Region

Endangered Species in the Pacific Islands

‘Akiapōlā‘au (hammerhead) / Hemingnathus munroi

Photo of ‘akia pola‘au The ‘akiapōlā‘au measures 4-1/2 to 5-1/2 inches in length. The male bird has a yellow head and lower body and an olive-green upper body. The female is smaller and duller in color. Their upper bill is curved and longer than the lower straight bill. This forest bird has a black bill and legs.
‘Akiapōlā‘au - Photo credit © Jack Jeffrey

Habitat & Behavior:
The ‘akiapōlā‘au only lives in high elevation ‘ōhi‘a-koa forests of the Big Island. This forest bird creeps along branches and uses its unique bill to pick out insect larvae.

When searching for food, it makes a tapping noise that can be mistaken for a woodpecker. These birds travel in family groups and like to fly with other flocks of forest birds.

The ‘akiapōlā‘au has two primary songs: a long warbling voice with a clear, rising whistle at the end "pit-er-ieu." Call note is a descending "cheew," repeated regularly. A soft and more variable whisper song had been reported. This endangered bird only lays one egg during the nesting season.

Past & Present:
The ‘akiapōlā‘au was fairly abundant and widely distributed on the Big Island until the 1970s. They once inhabited forests from central Kona to Hilo. Dwindling forests and competition from alien plants and animals have reduced the population to only 1,900 birds. The largest ‘akiapōlā ‘au population (about 900 birds) now lives in Hamakua; other smaller populations are at Ka‘u and Kona forests. This bird appears to favor koa forest at all locations. Scientists believe that the fragmentation and separation of the once connected Hamakua, Mauna Kea, Ka‘u, and Kona forests might have contributed to the decline in numbers. It is not known if different populations move from one area to another.

Conservation Efforts:
Scientists believe that linking the remaining ‘akiapōlā‘au populations would improve their survival into the future. Aggressive reforestation and fencing to keep goats, sheep, and cattle out would give the ‘akiapola‘au and other forest birds a fighting chance.

The ‘akiapōlā‘au was listed as an endangered species in 1967 under the Federal Endangered Species Act. The Hakalau Forest National Wildlife Refuge, the first such refuge established solely for the Hawaiian forest birds, provides a protected environment to live in for the ‘akiapōlā‘au and many other threatened and endangered birds. This species is also found in the Kona Forest Unit of Hakalau Forest NWR.


Last updated: September 20, 2012
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