The 'Akikiki, like the other endangered species on the island, is endemic to Kaua'i. Fossil records show that this species once inhabited forests down to sea level. First described in 1887, this small pale gray and white honeycreeper lacks the vibrant red and yellow colors worn by other extant honeycreepers on Kaua'i. Recent population estimates suggest that the population, already small at 3,924 ± 756 birds, is in decline and its range has contracted; these findings led to the federal listing of the species in 2010. Therefore, in 2011 KFBRP initiated long-term studies of 'Akikiki ecology and demography as described in the species' draft Five-year Recovery Plan to assess causes of the species' decline and inform its recovery.
Like the 'Akeke'e, the 'Akikiki has been the subject of only a few studies, many summarized in Hawai'i's Comprehensive Wildlife Conservation Strategy 'Akikiki Fact Sheet. The few 'Akikiki nests that have been found were all high in in the crowns of 'ōhi'a trees, and were composed of moss, small pieces of bark, bits of lichen, and fine plant fibers. 'Akikiki reproductive behavior has been observed from January through July. This species probably rarely, if ever, rears more than one brood per year because of the long juvenile dependency period: like other Hawaiian creepers, juvenile 'Akikiki may stay with their parents for up to 18 months.
'Akikiki are usually seen traveling and foraging in pairs or in family groups in forests of the Alaka'i area at elevations above 1,140 meters. They eat invertebrates, which they find by pecking and pulling at the bark of snags and tree trunks of species such as 'ōhi'a and 'ōlapa. Once an 'Akikiki pair or family group is spotted, they can be watched for long periods of time as they move up and down along branches in the understory. Identifying them by sight is easier than identifying them by sound, as 'Akikiki sound much like 'Akeke'e, 'Anianiau, and Kaua'i 'Amakihi.