Rhodacanthis, commonly known as the koa finches, is an Extinction genus of Hawaiian honeycreeper in the subfamily Carduelinae of the family Finch. All four species were Endemism to Hawaii.
Habitat and diet
Members of this genus were
Seed predation, with bills adapted to the
and pods of
. The two species that became extinct in the 1890s,
R. flaviceps and
R. palmeri, inhabited upper elevation mesic forests dominated by koa
(Acacia koa) on the island of Hawaii.
Both were large birds;
R. flaviceps measured , while
R. palmeri was in length.
The combination of a giant bill with brightly colored
plumage (yellow for
R. flaviceps, orange for
R. palmeri) gave the males a very striking appearance. Koa seeds were the preferred food for the two species, but
were taken if necessary. The two prehistoric species,
R. forfex and
R. litotes, were denizens of more lowland tropical dry forests and shrublands on
Kauai,
Maui, and
Oahu. It is speculated that koaia (
Acacia koaia) was an important food source for both species, as their range did not overlap with that of koa. Kanaloa (
Kanaloa spp.) pods and aalii (
Dodonaea viscosa)
Berry were probably also eaten in addition to the occasional caterpillar.
Species
-
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)
See also
