Hemignathus wilsoni
The Akiapolaau, *Hemignathus wilsoni*, is a critically endangered Hawaiian honeycreeper renowned for its extraordinary and highly specialized bill. This iconic passerine measures approximately 14 cm (5.5 inches) in length and weighs about 20-25 grams. Its most distinctive field mark is its unique bill, featuring a long, decurved upper mandible used for probing, and a short, stout, chisel-like lower mandible for excavating wood. Males typically exhibit bright olive-green upperparts, yellowish ...
Found exclusively in high-elevation (1,000-2,300 m) wet and mesic montane forests dominated by *Acacia koa* and *Metrosideros polymorpha* trees.
Primarily wood-boring insect larvae, especially from beetles, along with spiders, supplementing their diet with small amounts of nectar and tree sap.
Akiapolaau are diurnal birds, spending their days meticulously foraging, often alone or in pairs, rarely joining mixed-species flocks. Their foraging strategy is unique: the upper mandible probes crevices for insects, while the powerful lower mandible is used to chisel and hammer into wood, excav...
The Akiapolaau is endemic to Hawaiʻi Island, where its highly fragmented population persists in several key high-elevation montane forest tracts. Historically, it was also found on Maui, but these populations are now extinct. On Hawaiʻi Island, significant populations are found on the slopes of M...
Critically Endangered
- The Akiapolaau's bill is often called a 'Swiss Army knife' due to its two distinct parts: a long, curved upper mandible for probing and a short, stout lower mandible for chiseling. - Its Hawaiian name, 'Akiapolaau', translates roughly to 'axe-bill' or 'chip-axe', aptly describing its unique for...