The Kauaʻi nukupuʻu is an extinct species of nukupuʻu once found throughout parts of the Hawaiian island of Kauaʻi. It was an insect eater that picked out its tiny prey from tree bark. The males were yellowish with brown wings, while the females were grayish brown with a yellow throat streak.
Region
Hawaiian Islands
Typical Environment
Historically restricted to the island of Kauaʻi, especially in native wet and mesic forests dominated by ʻōhiʻa (Metrosideros polymorpha) and koa (Acacia koa). It foraged along trunks and larger branches, probing bark crevices and prying loose flakes to reach concealed insects. The species likely persisted longest in the remote Alakaʻi Plateau and adjacent cloud forests where mosquitoes were less common. Loss and degradation of lowland forests pushed it into higher, cooler elevations until it disappeared.
Altitude Range
600–1300 m
Climate Zone
Highland
Ease of Keeping
Beginner friendly: 1/5
The Kauaʻi nukupuʻu was a Hawaiian honeycreeper specialized for extracting insects from bark with its markedly decurved upper bill and shorter lower mandible, a woodpecker-like niche in forests without woodpeckers. Males were mostly yellow with brown wings, while females were gray-brown with a yellow throat streak. It vanished due to habitat loss, introduced diseases spread by mosquitoes, and severe storms that degraded high-elevation refugia. It is considered extinct, with no confirmed records in many decades.
Illustration from The Ibis, the brighter bird in the back
Temperament
solitary and territorial
Flight Pattern
short rapid wingbeats
Social Behavior
Typically observed singly or in pairs within forest territories. Likely formed monogamous pairs during the breeding season and defended foraging areas. Nests were presumably cup-shaped and placed in native trees, similar to related honeycreepers.
Migratory Pattern
Resident
Song Description
Calls were soft, thin whistles and chips, sometimes given as short series while foraging. Song was modest and high-pitched, often difficult to locate in dense canopy.
Plumage
Males bright yellow on head and underparts with brown wings and tail; females grayish-brown overall with a distinct yellowish throat streak. Both sexes show a clean contrast between the yellow tones and darker flight feathers. The bill is long with a strongly decurved upper mandible and a shorter, straighter lower mandible.
Diet
Primarily arthropods, especially beetle larvae, caterpillars, and other insects gleaned or pried from beneath bark and lichen. The specialized two-part bill allowed it to probe and then lever bark flakes to expose prey. It occasionally took small spiders and other invertebrates encountered on branches.
Preferred Environment
Forages on trunks and thicker branches of ʻōhiʻa and koa in mid to upper canopy. Prefers intact native forest with rough-barked trees and abundant epiphytes and lichens that harbor insects.
