Time Is Running Out: Maui’s Forest Birds Will Go Extinct without Action

The island of Maui is known for beautiful sand beaches, rich Hawaiian culture, and stunning biodiversity, but the island is at risk of losing one of its most iconic features – the native forest birds, a group of species found nowhere else on earth.

A variety of factors have contributed to the decline of Hawaiʻi’s forest birds. Due to human-induced impacts, the birds have had to face extreme challenges in a short period of time that they had never faced in their evolutionary history. One of the greatest contributors to the problem is non-native mosquitoes that spread diseases, particularly avian malaria. This disease is deadly to honeycreepers and has led to severe declines in populations and threatens many species with extinction. Despite the devastation wrought by these mosquitoes, a tool to turn the tide against extinction is within reach.

Before digging into the problems faced by Maui’s forest birds, familiarize yourself with the birds below.

Meet the Birds

These birds are not only important to the forest ecosystem on Maui, but also play a significant role in the Hawaiian culture. The following birds make their home on Maui and in Haleakalā National Park.

Historically, more than 50 species of honeycreepers lived on the Hawaiian Islands but today only 17 species remain. This on-going crisis has seen three species go extinct on Maui alone in the past 35 years and many more throughout the state teetering on the edge. The island of Maui and Haleakalā National Park are home to six of the remaining native forest bird species.

‘Apapane (Himatione sanguinea)
Status: Not threatened. Hawaiʻi Endemic.
The irrdescent red ʻapapane are often found busily working ʻōhiʻa lehua blossoms for nectar. This busy feeder stops at most flowers for just a few seconds, always on the move. The short black bill and black legs helps distinguish ʻapapane from the other red native bird, the ʻiʻiwi. Their songs include various mechanical chattering sounds that go on and on.

‘I‘iwi (Drepanis coccinea)
Status: Threatened, Vulnerable. Hawaiʻi Endemic.
Adult ʻiʻiwi are red, with black and white wings and have a slender, long, orange-colored bill. These honeycreepers seek flower nectar from a variety of sources. A wide variety of creaks, gurgles, and whistles creating a “rusty hinge” sound are characteristic of their calls and songs. Hosmer Grove is one of the best places to spot ʻiʻiwi especially when the yellow-flowered māmane shrubs are blooming.

Hawaiʻi ‘amakihi (Chlorodrepanis virens)
Status: Not threatened. Hawaiʻi Endemic.
The Hawaiʻi ʻamakihi is yellowish green in color with a short, slightly downcurved bill. Females and young birds are slightly less green with more gray and brown coloration. ʻAmakihi have a varied diet consisting of nectar and insects. They are known for their sneezy, whiney calls, sometimes even appearing to scold passing birdwatchers.

Maui ‘alauahio (Paroreomyza montana)
Status: Not threatened, but declining. Maui Endemic.
The small, bright yellow ʻalauahio are rarely alone, often travelling in family groups as they “chip” to one another constantly. Young birds are gray. These insectivores are sometimes mistaken for the greener ʻamakihi that also has a downcurved bill compared to the straight, pink bill of the ʻalauahio. Their song consists of a repeated whistled phrase described as: “whichy-wheesee-whurdy-whew”. These birds are often seen at Hosmer Grove and at Palikū Cabin.

Kiwikiu (Maui Parrotbill) (Pseudonestor xanthophrys)
Status: Endangered. Maui Endemic. Fewer than 200 birds remain.
The stocky kiwikiu, olive green above and yellow below, get their English name for their large, hooked bills, which they employ to split branches in search of insects in high elevation wet forests. With so few individuals remaining, these birds are very rarely seen outside of dense native forest beyond the public view, extremely unlikely even at Hosmer Grove. Its call is a short “chip,” very much like that of ʻalauahio or a whistle like ʻiʻiwi and its song consists of repeated whistled “cheery” notes that often go down in pitch. The kiwikiu’s original Hawaiian name was lost. In 2010, the Hawaiian Lexicon Committee renamed it “kiwikiu:” “kiwi” for its curved beak and “kiu” for its secretive behavior.

ʻĀkohekohe (Palmeria dolei)
Status: Endangered. Maui Endemic. Fewer than 2,000 birds remain.
Ākohekohe or Crested Honeycreeper is one of the largest honeycreeper species. Primarily black with striking orange-red tipped body feathers. Its throat and breast feathers are tipped with silvery-white. They are primarily nectarivorous, but also feed on insects and spiders. Vocalizations include various guttural clucking gurgles, raspy croaks, and buzzing sounds, resembling something you’d expect from a frog. Like kiwikiu, ʻākohekohe were once found on Molokaʻi but are now found in just a small strip of high elevation native forest on Haleakalā volcano. ʻĀkohekohe are hard for visitors to observe as they stick to intact native forest; juvenile ʻapapane are sometimes mistaken for this species at Hosmer Grove.

Declining Populations

A number of factors have led to the declines and extinctions of these endemic birds, largely falling into three categories, introduced species, habitat destruction, and climate change.

Until relatively recently there were no mosquitoes present in Hawaiʻi. In 1826, the southern house mosquito was introduced by a whaling vessel in Lahaina, the first mosquito of any kind in Hawaiʻi. Not long after, a mosquito-borne disease known as avian malaria was also introduced to Hawaiʻi and has played a major part in the extinction of many native forest birds.

Avian malaria is a fatal disease that can kill a forest bird with just one bite from its mosquito host. Unfortunately, climate change and rising temperatures have given this mosquito more power by increasing its habitat range, allowing it to expand to higher elevations and invade more and more of the forest birds’ habitat.

Shrinking habitat and other threats paint a grim picture for these special birds and without intervention, they could be lost forever.

Hope on the Horizon

There is hope for Maui’s native forest birds, but it requires fast action and significant conservation efforts. Haleakalā National Park, in partnership with the State of Hawaiʻi and other agencies, are fighting to ensure something is done to save the remaining species.

With the use of Wolbachia, a naturally-occurring bacteria that prevents successful mosquito reproduction, scientists can reduce Maui's invasive mosquito population and combat the spread of avian malaria.

The Wolbachia bacteria lives only within the cells of insects, including the southern house mosquitoes on Maui, and some other arthropods. Scientists have discovered that mosquitoes with different strains of Wolbachia are unable to reproduce with each other.

Using a method known as Incompatible Insect Technique (IIT), scientists can take advantage of this discovery and raise male mosquitoes (which do not bite) in a lab with one strain of Wolbachia and release them into an area with mosquitoes with a different strain. When the wild females find and mate with these lab mosquitoes, their Wolbachia doesn’t match and none of her eggs hatch.

As a result of this safe, targeted technique, the mosquito population will crash, giving our forest birds a fighting chance.

Learn more about Wolbachia and its powerful role in preventing extinction of forest birds.