Data Zone
Justification of Red List category
Endemic to Kaua'i, H. hanapepe became confined to the Alaka'i Swamp and, according to USFWS (2023) and Pratt and Pyle (2000), the last confirmed record was two specimens taken by Munro in 1899. Since its ‘rediscovery’ in 1960 (Richardson and Bowles 1964) there were at least 30 reports, the most recent of which was in 2007 (Pratt 2010). There have been no records since, despite extensive searches. Following methods developed in a series of papers published in 2017 (Akcakaya et al. 2017, Keith et al. 2017, Thompson et al. 2017), the probability that the species is extinct based on records and surveys is 0.92, and the probability it is extinct based on threats is 0.97. Accordingly, it is classified as Extinct.
Population justification
Many consider the last confirmed record of H. hanapepe to have been two specimens taken in 1899 (Pratt and Pyle 2000, Pyle and Pyle 2017, USFWS 2022). Despite there being at least 30 subsequent sightings since 1960, the most recent of which was in 2007 (Pratt 2010), it has been argued that none are accompanied by sufficient evidence to eliminate possible confusion with Chlorodrepanis stejnegeri (Pratt and Pyle 2000). Following methods developed in a series of papers published in 2017 (Akcakaya et al. 2017, Keith et al. 2017, Thompson et al. 2017), the probability that this species is extinct based on records and surveys is 0.93, and the probability it is extant based on threats is 0.97. It is accordingly considered Extinct with a population size of 0. The species is likely to have always been rare: early collectors noted that it was rare or uncommon (Pyle and Pyle 2017) and there was a large gap in records between 1899 and its apparent 'rediscovery' (although see above) in 1960 (Richardson and Bowles 1964). In addition to the extinction probability assessment made here, the USFWS (2023) delisted H. hanapepe from the Federal Lists of Endangered and Threatened Wildlife and Plants due to presumed extinction, which they believe occurred in the early 20th century.
Trend justification
This species is considered extinct. Many consider the last confirmed record of H. hanapepe to have been two specimens taken in 1899 (Pratt and Pyle 2000, Pyle and Pyle 2017, USFWS 2022). Despite there being at least 30 subsequent sightings since 1960, it is argued that none are accompanied by sufficient evidence to eliminate possible confusion with Chlorodrepanis stejnegeri (Pratt and Pyle 2000).
Hemignathus hanapepe was endemic to Kaua'i in the Hawaiian Islands, U.S.A., where the last confirmed record was two specimens taken in 1899 (Munro 1960). It probably became confined to the Alaka'i Wilderness Preserve (Scott et al. 1986, Conant et al. 1998) and since its 'rediscovery' in 1960 (Richardson and Bowles 1964) it has been reported there at least 30 times. Although at least some, if not all, of these sightings lack sufficient evidence to eliminate Chlorodrepanis stejnegeri (Pratt and Pyle 2000).
This species inhabited dense, wet 'ohi'a forest and the higher parts of mesic koa-'ohi'a forest (Scott et al. 1986, Pratt et al. 1987), where it fed on wood-borers, spiders and beetles (Scott et al. 1986, Conant et al. 1998). It hunted along the upper and lower surfaces of branches, both up and down the trunks (Perkins 1903) probing the bark on living and dead trees. It also gleaned caterpillars from the leaves of low trees (Munro 1960). According to Munro (1960), when feeding it would insert its longer, decurved, upper mandible into crevices and holes to hook out arthropods and then catch them with its tongue and lower mandible. The Koa'e Valley in the Alaka'i Wilderness Preserve (where it was potentially seen in 1995 [Conant et al. 1998]) is at 1,000-1,300 m (Pratt 1994), although it was previously seen as low as 600m (Perkins 1903).
Since the arrival of humans in the Hawaiian Archipelago, Hawai’i’s forest birds have undergone tremendous losses and face a panoply of threats. At least 71 taxa of Hawaiian birds disappeared before the arrival of Captain James Cook in 1778, 24 more have been extirpated since (Banko and Banko 2009).
With the arrival of the Polynesians between 1000 and 1200 CE, almost all lowland forests were felled and burned to make way for agriculture (Kirch 1982). This loss continued with the arrival of European and American settlers. Forests continued to be cleared until only high-elevation forest remained. Much of the forest that remains has been invaded by non-native species.
Hawai’i has a long history of non-native species. When the Polynesians arrived, they brought with them pigs Sus scrofa, dogs Canis familiaris and Polynesian Rats Rattus exulans. With the Europeans and Americans came Black R. rattus and Brown Rats R. norvegicus, cats Felis catus, mongoose Herpestes auropunctatus, feral goats Capra hircus, cattle Bos taurus, deer Axis axis, more than 50 species of birds (Atkinson and Lapointe 2009), plants, invertebrates, and diseases. Introduced ungulates have severely damaged forest structure through herbivory and the dispersal of invasive plants, rendering it far less suitable for Kauai Nukupuu and other forest birds. Rats, cats and mongoose predate both nests and adult birds (Lindsey et al. 2009), while non-native birds may also compete with them for resources (Foster 2009). Non-native avian diseases introduced to Hawai'i are some of the most pervasive threats faced by native birds and are likely to be the main cause of many previous extinctions.
Both avian malaria Plasmodium relictum and avian pox Avipoxvirus spp. are transmitted by the Southern House Mosquito Culex quinquefasciatus, currently climatically restricted to elevations below 1,500 m and responsible for the disappearance of many highly susceptible Hawaiian forest birds from elevations below this. Kaua'i has no forest above 1,500 m and therefore offers no refugia from these fatal diseases. Wallows created by feral pigs provide additional breeding habitats for Culex and allow it to infiltrate deeper into forests (Lapointe et al. 2009).
14 cm. Medium-sized honeycreeper with strongly downcurved "heterobill" in which mandible is half the length of maxilla. Male golden-yellow on head and breast, shading to white on belly and undertail-coverts. Crown, nape, postocular line and posterior edge of ear-coverts slightly tinged greenish, yellowish-green upper-parts. Black lores, eye-ring, and bill. Female greenish-grey above, mostly dull white below with yellow restricted to chin, upper throat, and supraloral patch. Similar spp. Kauai Amakihi H. kauaiensis has paler bill, less head/back contrast, and dingier underparts. Maui Parrotbill Pseudonestor xanthophrys rather similar in plumage, but much heavier bill. Voice Song a short warble, call ke-wit, both similar to voice of Akiapolaau H. munroi of Hawai'i.
Text account compilers
Vine, J., Nesbit, D.
Contributors
Baker, H.C., Baker, P.E., Camp, R., Fretz, S., Gorresen, M., VanderWerf, E., Woodworth, B., Morin, M., Berthold, L., Bird, J., Taylor, J., Westrip, J.R.S., Derhé, M., Isherwood, I., Butchart, S., Crampton, L., Benstead, P., Khwaja, N., Stuart, T., Wheatley, H., Symes, A., Stattersfield, A. & Jeffrey, J.
Recommended citation
BirdLife International (2024) Species factsheet: Kauai Nukupuu Hemignathus hanapepe. Downloaded from
https://datazone.birdlife.org/species/factsheet/kauai-nukupuu-hemignathus-hanapepe on 22/12/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from
https://datazone.birdlife.org/species/search on 22/12/2024.