Stand in the Hawaiian cloudforest and close your eyes. The whirrr whirrr whirr of ʻapapane wings above you is a signature sound of the native forest. These striking red, black, and white birds (Himatione sanguinea) are constantly on the move, seeking the nectar of ʻōhiʻa lehua flowers. Small flocks work the canopy, restless and determined. A side development of this continual travel among the blossoms is that this is one of the most important pollinators of the native forest. ʻApapane chatter fills the trees all day, although the hour before sunset seems to swell the chorus. In the Hawaiian creation chant, The Kumulipo, the ʻapapane was one of the first beings born into the world.
The mosquito, capable of carrying deadly diseases between birds, arrived as larvae in the water barrels of whalers stopping over in Hawaiʻi in the early 1800s. Its arrival coincided with the introduction of birds (and their diseases) from all over the world by the new, primarily Western, arrivals to the islands, and once established contributed to a perfect storm of Hawaiian bird extinctions. To experience our forest birds now, you must climb the slopes of the volcanoes to pass through the bellies of the lowest clouds at about 4,000 to 5,000 feet above sea level. There, you may be treated to the sights and sounds of some of these most precious residents of the Hawaiian archipelago.
The crimson ʻiʻiwi (Drepanis coccinea) was once one of the most commonly encountered birds of the forest. With its rusty, fluted call, its fierce little face, and a bill that decurves dramatically to sip nectar from long endemic lobelia flowers, it is now a Life Lister for most birders. Visit Hosmer Grove near 7,000ft. at Haleakalā National Park, or take a hike from the shelter at the terminal end of Mauna Loa Road in Hawaiʻi Volcanoes National Park, and you may be one of the few lucky ones who catches this busy bird climbing between scarlet ʻōhiʻa lehua blossoms in the mist, on the hunt for flower nectar. This iʻiwi is exquisitely sensitive to habitat disturbance and infection, but was once so common that it provided the bright red feathers that set apart the cloaks, helmets, and lei of the Hawaiian aliʻi (those of royal rank) from commoners. Hundreds of thousands of feathers were required to create some of these items of great status.
On Maui, the kiwikiu, or Maui parrotbills (Pseudonestor xanthophrys), use their stocky, serious bills to pry up the bark on trees in order to get to the tasty insects hiding underneath. Watched carefully by scientists, the kiwikiu are perilously close to extinction, with a population numbering roughly 300 on just over 7,000 forest acres on the side of Haleakalā Volcano. Kiwikiu are shaded an olive-green on top, greenish-yellow below, and sport a streak of bright yellow above a steady black eye. They seem especially sensitive to mosquito-borne bird diseases, and ecologists are frantically working to save the species. Some kiwikiu were moved to an experimental second home on the high slope of the volcano, but to the shock of everyone mosquitoes moved in quickly and the birds were fatally infected. The lifespan of a kiwikiu is thought to be about 15 years, but humans will need to move fast in order to ensure that the young hatchlings of 2024 have a home in the islands.
Fortunately, mosquitoes really do not do well with cold. For the native forest birds, that means there is sanctuary from the transmission of infection above what ecologists call “the mosquito line”, that loose elevation line mentioned above, below which the stews of pathogens swirl in the warmth. Up here, there is hope to buy a little time. The two largest Hawaiʻi national parks, Hawaiʻi Volcanoes and Haleakalā, encompass the high flanks of large volcanoes, serving as two of the last de facto refuges for forest birds that once flitted like bright, chattery confetti through blossoming branches all the way to the salty edge of the sea.
National park scientists closely tracking climate change effects in the Hawaiian Islands already see shifts in rainfall, wind intensity, and the distribution of living things. The islands are becoming drier and warmer, and the mosquito line is moving higher. As the forests attempt to adapt to these changes, the birds that depend on these forests must be able to adapt as well or vanish. Above the highest tree line there is cold cinder desert summit, so native birds are sandwiched in a living green forest band that is being compromised from below, and which can expand no higher. This is a dilemma, and a time-intensive one. As of this writing, focus has intensified on mosquito eradication. This is one creature with wings that is not native, not welcome, and is hopefully one day just the whine of a cautionary tale.
To learn more about mosquitos and Haleakalā National Park: https://www.nps.gov/hale/learn/nature/birds-not-mosquitoes.htm
To learn more about the native forest birds of Hawaiʻi Volcanoes National Park: https://www.nps.gov/im/pacn/havo-native-birds.htm
For an excellent Hawaiʻi bird guide book: https://shop.hawaiipacificparks.org/products/hawaiis-birds
Image of ʻiʻiwi on ʻōhiʻa mamo blossoms by NPS VIP photographer Janice Wei.
