The scarlet 'i'iwi is one of Hawaii's most beautiful forest birds, but its long-term survival is threatened by avian diseases.
"As the 'i'iwi feeds, you see a demonstration of evolutionary adaptation."
By Sam ʻOhu Gon
Cloaked in the light mist of the East Maui forest, you wait. Craning your neck upward, squinting against the pale back-lit glare in your binoculars, you search for any of Hawaii’s small, colorful native forest birds.
As you rest your eyes and stretch your neck from this bird-searching exercise, you notice that right in front of you, at eye level, is the spectacular scarlet colored ‘i‘iwi, which has flown down from the canopy to feed on the blossoming flowers of a native lobelia.
As the ‘i‘iwi feeds, you witness a demonstration of evolutionary adaptation: the bird’s salmon sickle-shaped bill is a perfect match for the sickle-shaped lobelia flowers from which it is feeding. The brilliant scarlet feathers, and contrasting black wings and tail, command your attention, and its loud “rusty-hinge” call is unmistakable.
Threatened With Extinction
One of Hawaii’s most beautiful birds, the 'i'iwi was prized by Hawaiians for its striking vermillion feathers, which were used to make feather capes, helmets and other symbols of Hawaiian royalty. The ‘i‘iwi was once abundant on each of the main Hawaiian high islands, but the introduction of mosquitoes in the early 1800s significantly impacted its population. Mosquitoes transmit bird malaria, and native birds are particularly susceptible.
Today, threatened by habitat destruction, introduced predators and avian diseases, the ‘i‘iwi is extinct on the island of Lāna‘i, and is considered extremely rare and vulnerable to extinction on O‘ahu and Moloka‘i.
Fortunately, the ‘i‘iwi is still common in mosquito-free areas above 1,000 meters (3,280 feet) elevation on the islands of Hawai‘i, Maui, and Kaua‘i. Feral pig populations and global warming threaten to carry mosquito populations to higher elevations if left unchecked. The introduced mammals create wallows in which mosquitoes breed. The mosquitoes, in turn, spread avian malaria to native birds, which, having evolved in isolation, are defenseless against these introduced diseases.
Two weeks after a single bite from a disease-laden mosquito, an ‘i‘iwi will lie dead on the forest floor.
The Nature Conservancy is working with its partners to keep pigs and other feral animals out of the upper elevation forests so that the beautiful ʻiʻiwi and other endangered Hawaiian plants and animals can find refuge and survive well into the future.