|ʻIʻiwi (Drepanis coccinea)|
Hawaiian honeycreepers are a group of small birds endemic to Hawaiʻi. They are members of the finch family Fringillidae, closely related to the rosefinches (Carpodacus), but many species have evolved features unlike those present in any other finch. Their great morphological diversity is the result of adaptive radiation in an insular environment. Many have been driven to extinction since the first humans arrived in Hawaii, with extinctions increasing over the last 2 centuries following European discovery of the islands, with habitat destruction and especially invasive species being the main causes.
Before the introduction of molecular phylogenetic techniques, the relationship of the Hawaiian honeycreepers to other bird species was controversial. The honeycreepers were sometimes categorized as a family Drepanididae, other authorities considered them a subfamily, Drepanidinae, of Fringillidae, the finch family. The entire group was also called Drepanidini in treatments where buntings and American sparrows (Passerellidae) were included in the finch family; this term is preferred for just one subgroup of the birds today. Most recently, the entire group has been subsumed into the finch subfamily Carduelinae.
The Hawaiian honeycreepers are the sister taxon to the Carpodacus rosefinches. Their ancestors are thought to have been from Asia and diverged from Carpodacus about 7.2 million years ago, and they are thought to have first arrived and radiated on the Hawaiian Islands between 5.7-7.2 million years ago, which was roughly the same time that the islands of Ni'ihau and Kauai formed. The lineage of the recently extinct po'ouli (Melamprosops) was the most ancient of the Hawaiian honeycreeper lineages to survive to recent times, diverging about 5.7-5.8 million years ago. The lineage containing Oreomystis and Paroreomyza was the second to diverge, diverging about a million years after the po'ouli's lineage. Most of the other lineages with highly distinctive morphologies are thought to have originated in the mid-late Pliocene, after the formation of Oahu but prior to the formation of Maui. Due to this, Oahu likely played a key role in the formation of diverse morphologies among honeycreepers, allowing for cycles of colonization and speciation between Kauai and Oahu.
The classification of Paroreomyza and Oreomystis as sister genera and forming the second most basal group is based on genetic and molecular evidence, and has been affirmed by numerous studies; however, when morphological evidence only is used, Paroreomyza is instead the second most basal genus, with Oreomystis being the third most basal genus and more closely allied with the derived Hawaiian honeycreepers, as Oreomystis shares traits with the derived honeycreepers, such as a squared-off tongue and a distinct musty odor, that Paroreomyza does not. This does not align with the genetic evidence supporting Paroreomyza and Oreomystis as sister genera, and it would be seemingly impossible for only Paroreomyza to have lost the distinctive traits but Oreomystis and all core honeycreepers to have retained or convergently evolved them, thus presenting a taxonomic conundrum.
Viridonia (containing the greater ʻamakihi) may be associated with or even synonymous with the genus Aidemedia (containing the prehistoric icterid-like and sickle-billed gapers), and has the most debated taxonomy; it was long classified within the "greater Hemignathus" radiation (a now-paraphyletic grouping containing species formerly lumped within Hemignathus, including Hemignathus, Akialoa, and Chlorodrepanis) and while some sources speculate it as being sister to Chlorodrepanis (containing the lesser ʻamakihis), other sources speculate it may be a sister genus to the genus Loxops (containing the 'akepas, ʻakekeʻe and ʻalawī).
Today, the flowers of the native ʻōhiʻa (Metrosideros polymorpha) are favored by a number of nectarivorous honeycreepers. The wide range of bill shapes in this group, from thick, finch-like bills to slender, down-curved bills for probing flowers have arisen through adaptive radiation, where an ancestral finch has evolved to fill a large number of ecological niches. Some 20 species of Hawaiian honeycreeper have become extinct in the recent past, and many more in earlier times, following the arrival of humans who introduced non-native animals (ex: rats, pigs, goats, cows) and converted habitat for agriculture.
Genera and species
The term "prehistoric" indicates species that became extinct between the initial human settlement of Hawaiʻi (i.e., from the late 1st millennium AD on) and European contact in 1778.
- Genus Aidemedia Olson & James, 1991 – straight thin bills, insectivores
- Genus Akialoa Olson & James, 1995 – pointed, long and down-curved bills, insectivorous or nectarivorous
- Akialoa ellisiana Gray, 1859 – Oʻahu ʻakialoa (extinct, 1940)
- Akialoa lanaiensis Rothschild, 1893 – Maui Nui ʻakialoa (extinct, 1892)
- Akialoa stejnegeri Wilson, 1889 – Kauaʻi ʻakialoa (extinct, 1969)
- Akialoa obscura Cabanis, 1889 – lesser ʻakialoa (extinct, 1940)
- Akialoa upupirostris – hoopoe-billed ʻakialoa (prehistoric)
- Genus Chloridops Wilson, 1888 – thick-billed, hard seed (e.g. Myoporum sandwicense) specialist
- Genus Chlorodrepanis Olson & James, 1995 – pointed bills, insectivorous and nectarivorous
- Genus Ciridops Newton, 1892 – finch-like, fed on fruit of Pritchardia species
- Genus Drepanis Temminck, 1820 – down-curved bills, nectarivores
- Genus Dysmorodrepanis Perkins, 1919 – pincer-like bill, possibly snail specialist
- Genus Hemignathus Lichtenstein, 1839 – pointed or long and down-curved bills, insectivorous
- Genus Himatione – thin-billed, nectarivorous
- Genus Loxioides Oustalet, 1877 – finch-like, Fabales seed specialists
- Genus Loxops – small pointed bills with the tips slightly crossed, insectivorous
- Genus Magumma - small pointed bills, insectivorous and nectarivorous
- Genus Melamprosops Casey & Jacobi, 1974 – short pointed bill, insectivorous and snail specialist
- Melamprosops phaeosoma Casey & Jacobi, 1974 – poʻouli (extinct, 2004)
- Genus Oreomystis Wilson, 1891 – short pointed bills, insectivorous
- Genus Orthiospiza – large weak bill, possibly soft seed or fruit specialist?
- Genus Palmeria Rothschild, 1893 – thin-billed, nectarivorous, favors Metrosideros polymorpha
- Genus Paroreomyza – short pointed bills, insectivorous
- Paroreomyza maculata Cabanis, 1850 – Oʻahu ʻalauahio (possibly extinct, early 1990s?)
- Paroreomyza flammea (Wilson, 1889) – kākāwahie (extinct, 1963)
- Paroreomyza montana
- Genus Pseudonestor – parrot-like bill, probes wood for insect larvae
- Genus Psittirostra – slightly hooked bill, Freycinetia arborea fruit specialist
- Genus Rhodacanthis – large-billed, granivorous, legume specialists
- Rhodacanthis flaviceps Rothschild, 1892 – lesser koa-finch (extinct, 1891)
- Rhodacanthis forfex James & Olson, 2005 – scissor-billed koa-finch (prehistoric)
- Rhodacanthis litotes James & Olson, 2005 – primitive koa-finch (prehistoric)
- Rhodacanthis palmeri Rothschild, 1892 – greater koa-finch (extinct, 1896)
- Genus Telespiza Wilson, 1890 – finch-like, granivorous, opportunistic scavengers
- Genus Vangulifer – flat rounded bills, possibly caught flying insects
- Genus Viridonia
- Genus Xestospiza James & Oslon, 1991 – cone-shaped bills, possibly insectivorous
Hawaiian honeycreepers were formerly classified into three tribes – Hemignathini, Psittirostrini, and Drepanidini – but they are not currently classified as such.
- Lerner, H.R.L.; Meyer, M.; James, H.F.; Fleischer, R.C. (2011). "Multilocus resolution of phylogeny and timescale in the extant adaptive radiation of Hawaiian Honeycreepers". Current Biology. 21 (21): 1838–1844. doi:10.1016/j.cub.2011.09.039. PMID 22018543.
- Zuccon, Dario; Prŷs-Jones, Robert; Rasmussen, Pamela C.; Ericson, Per G.P. (2012). "The phylogenetic relationships and generic limits of finches (Fringillidae)" (PDF). Molecular Phylogenetics and Evolution. 62 (2): 581–596. doi:10.1016/j.ympev.2011.10.002. PMID 22023825.
- Clements, J. 2007. The Clements Checklist of the Birds of the World. 6th ed. ISBN 978-0-7136-8695-1
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- Gill, Frank; Donsker, David (eds.). "Finches, euphonias". World Bird List Version 5.2. International Ornithologists' Union. Retrieved 5 June 2015.
- Lerner, Heather R.L.; Meyer, Matthias; James, Helen F.; Hofreiter, Michael; Fleischer, Robert C. (2011-11-08). "Multilocus Resolution of Phylogeny and Timescale in the Extant Adaptive Radiation of Hawaiian Honeycreepers". Current Biology. 21 (21): 1838–1844. doi:10.1016/j.cub.2011.09.039. ISSN 0960-9822. PMID 22018543.
- "A consensus taxonomy for the Hawaiian honeycreepers » Malama Mauna Kea Library Catalog". www.malamamaunakea.org. Retrieved 2021-04-17.
- Pratt, H Douglas (2002). The Hawaiian Honeycreepers. Oxford University Press. p. 46. ISBN 978-0-19-854653-5.
- Pratt, H. Douglas (1992). "Is the Poo-uli a Hawaiian Honeycreeper (Drepanidinae)?" (PDF). The Condor. Cooper Ornithological Society. 94 (1): 172–180. doi:10.2307/1368806. JSTOR 1368806.
- Olson, Storrs L.; James, Helen F (1991). "Descriptions of Thirty-Two New Species of Birds from the Hawaiian Islands: Part I. Non-Passeriformes". Ornithological Monographs. 45 (45): 1–91. doi:10.2307/40166794. hdl:10088/1745. JSTOR 40166794.
- James, Helen F.; Olson, Storrs L (1991). "Descriptions of Thirty-Two New Species of Birds from the Hawaiian Islands: Part II. Passeriformes". Ornithological Monographs. 46 (46): 1–92. doi:10.2307/40166713. hdl:10088/1746. JSTOR 40166713.
- Beolens, Bo; Watkins, Michael; Grayson, Michael (2014). The Eponym Dictionary of Birds. Johns Hopkins University Press. ISBN 9781472905741. The genus Aidemedia is named in honor of Joan Aidem.
- James, Helen F; Storrs L. Olson (2003). "A giant new species of nukupuu (Fringillidae: Drepanidini: Hemignathus) from the island of Hawaii". The Auk. 120 (4): 970–981. doi:10.1642/0004-8038(2003)120[0970:AGNSON]2.0.CO;2. S2CID 41112065.
- James, Helen F.; Johnathan P. Prince (May 2008). "Integration of palaeontological, historical, and geographical data on the extinction of koa-finches". Diversity & Distributions. 14 (3): 441–451. doi:10.1111/j.1472-4642.2007.00442.x. S2CID 40057425.
- Groth, J. G. 1998. Molecular phylogeny of the cardueline finches and Hawaiian honeycreepers. Ostrich, 69: 401.