Red Birds in Hawaii: Two Stories, Two Altitudes

Walk into the ohia forest above 4,500 feet on Hawaii’s Big Island in late spring and you will hear the Iiwi before you see it. The call is a rusty creak, almost apologetic for a bird so outrageously built. Then it emerges: Drepanis coccinea, scarlet from bill to tail, the long decurved salmon-orange bill moving from blossom to blossom with the precision of a lockpick.

Hawaii’s native red species - the Iiwi and the Apapane - evolved here over millions of years from a single ancestral finch colonist. Every other red bird on the islands arrived within the last two centuries, brought by humans and now thoroughly embedded in the lowland landscape the honeycreepers once owned. The two stories are connected, and not in a comfortable way.

The native birds

Apapane (Himatione sanguinea) is the more forgiving of the two to find. Cornell’s All About Birds describes it as deep crimson with black wings, a black tail, and white undertail coverts - its tail characteristically cocked upward. The bill is curved and black, built for nectar. Birds returning from heavy feeding on ohia lehua blossoms often carry visible orange pollen on their faces.

Apapane feed almost entirely on the nectar of ohia lehua (Metrosideros polymorpha), the native tree whose red pompom flowers dominate Hawaii’s montane forest. The Maui Forest Bird Recovery Project notes it is the most abundant native honeycreeper in the archipelago, with strong populations on Kauai, Maui, and Hawaii Island. At Hakalau Forest on the Big Island and Hosmer Grove on Maui, loose flocks work the ohia blossoms from first light.

Iiwi is the one most people make the trip for. The body is fiery scarlet-red. The wings and tail are black. That salmon-orange bill is deeply curved and designed for lobelioid flowers - a lock-and-key coevolution that took millions of years to close. Nothing on the US mainland has a bill like it.

According to the US Fish and Wildlife Service, the Iiwi was listed as threatened under the Endangered Species Act on September 20, 2017. Audubon reported a population of roughly 600,000 birds at the time of listing. But 90 percent of those birds were confined to a narrow band of forest on the windward slopes of the Big Island and East Maui, between approximately 4,265 and 6,234 feet in elevation. The Kauai population had already plummeted 92 percent over the preceding 25 years.

Species	Elevation	Best site
Iiwi	Above 4,265 ft	Big Island, East Maui
Apapane	Above 4,100 ft	Big Island, Maui, Kauai
Red-crested Cardinal	Sea level to 2,000 ft	Oahu, Kauai
Northern Cardinal	Sea level to 3,000 ft	All main islands

Avian malaria kills approximately 95 percent of the Iiwi it infects, according to Audubon. The birds’ entire viable range is now determined not by food or habitat but by the upper elevational limit of the mosquito that carries it.

Both native honeycreepers are under sustained pressure. The southern house mosquito (Culex quinquefasciatus) was introduced to Lahaina, Maui, reportedly in 1826. It carries Plasmodium relictum, the parasite that causes avian malaria. Hawaiian honeycreepers evolved with no mammal predators and no mosquitoes. They had no immunity to blood parasites.

The American Bird Conservancy reports that of approximately 59 honeycreeper species that evolved from a single rosefinch ancestor over six million years, only around 17 survive today. Fourteen of those are federally listed as endangered.

The birds that remain survive by retreating upward. Culex mosquitoes cannot breed effectively in the cold above roughly 4,000 feet. Climate change is now compressing the refugia from below: USFWS analysis projected that Iiwi could lose 60 to 90 percent of their disease-free range by the end of the century.

In November 2023, Haleakala National Park and its partners began releasing Wolbachia-infected male mosquitoes over the park’s native forest by drone - 250,000 per week in biodegradable pods. Male mosquitoes do not bite. When they mate with wild females, the eggs fail to hatch. The project is an attempt to crash the Culex population before warming brings malaria into the last safe forest.

The introduced birds

Red-crested Cardinal (Paroaria coronata) arrived from South America between 1928 and 1931 and is now the most visible red bird at lower elevations on Oahu. The red head and crest on a white and grey body is unmistakable. It is not a true cardinal - Paroarias are tanagers - though anyone scanning Waimea Valley or Ala Moana Beach Park will spot one quickly. For mainland context on red-headed birds, see orange birds in Ohio or orange birds in Arizona.

Northern Cardinal (Cardinalis cardinalis) was introduced to Hawaii and is now common in gardens across all main islands. His song - the clear whistled phrases familiar from a yard in Ohio or Illinois, described in the Northern Cardinal field guide - sounds surreal against trade-wind palms. His feathers follow the same annual molt cycle that leaves mainland birds temporarily bald in August. Hawaii cardinals do the same.

House Finch (Haemorhous mexicanus) is ubiquitous in suburban areas. The male wears red as a wash on head, breast, and rump rather than a full-body statement. He is common enough to overlook, which is the fate of most successful colonisers.

This is the position worth taking: the cheerful Red-crested Cardinal in Kapiolani Park and the Iiwi above Hakalau are not two unrelated facts about Hawaii’s birds. They are cause and consequence, separated by roughly 200 years and 4,000 feet of elevation. The native honeycreepers did not retreat to the high forest because they prefer it. They retreated because the lowlands became lethal.

Where to go

Hakalau Forest National Wildlife Refuge on the Big Island is the best single site for native honeycreepers. Access requires advance reservation and a high-clearance vehicle. Hosmer Grove on Maui, inside Haleakala National Park, is more accessible and holds Apapane reliably. Both reward early starts.

For introduced species, Kapiolani Park in Honolulu is the classic site for Red-crested Cardinal.