The 'Akikiki is an energetic, bicolored Hawaiian honeycreeper endemic to the island of Kaua'i in the Hawaiian Archipelago. Appearing gray above, white below, with a short and slightly decurved pale-pink bill, the 'Akikiki can be found only in montane forests of the central section of the island. Also called the Kaua'i Creeper, the 'Akikiki is known for its characteristic creeping behavior when foraging, reminiscent of nuthatches (Sittidae). It is predominantly insectivorous, feeding on caterpillars, beetles, and other arthropods on the bark and leaves of native trees and shrubs; it forages alone, in pairs, or in family groups of 3 or 4. Although now rarely seen outside of the breeding season, the 'Akikiki forms large single-species flocks of 8-12 birds or mixed-species flocks with 'Anianiau (Hemignathus parvus), 'Akeke'e (Loxops caeruleirostris), and Kaua'i 'Amakihi (Hemignathus kauaiensis).
Leonhard Stejneger ( Stejneger 1887 ) first described the species from a specimen collected by Valdemar Knudsen, a local naturalist. Collectors in this early exploratory era described the 'Akikiki as "abundant" ( Perkins 1903 ) and ubiquitous at elevations over 300 m (Rothschild 1893-1899). The Hawaiian Forest Bird Survey on Kaua'i Island in 1981 also found the bird to be common, but only in the more remote parts of its range ( Scott et al. 1986 ). They noted that this contraction in range was particularly distressing because it resembled the "pattern of population decline and retreat" (p. 141) seen in other Kaua'i forest birds that are now extinct or critically endangered. The 2000 Kaua'i Forest Bird Survey (KFBS) verified this contraction of the 'Akikiki's range and indicated that the 'Akikiki population has drastically declined in the past 30 years.
The 'Akikiki has been besieged by the same factors that have devastated other native Hawaiian bird populations, including habitat loss; degradation of habitat by introduced plants, invertebrates, and feral ungulates; introduced predators; and avian diseases. In addition, hurricanes in 1982 and 1992 heavily impacted forest-bird habitats on Kaua'i Island. Despite the decline of the species, the 'Akikiki has never been the focus of a research study, and it remains one of the least understood of the extant birds in the Hawaiian Islands.
Where relevant, comparisons in this account have been made with the Hawai'i Creeper (Oreomystis mana) and Maui 'Alauahio (Paroreomyza montana newtoni). Classification of the Hawai'i Creeper in the same genus with the 'Akikiki is disputed, however, and additional research is needed to resolve the issue (see Systematics: related species, below).