Hawaiian honeycreepers are the textbook example of an adaptive radiation: a single finch-like colonist arriving on a remote archipelago and diversifying into a family of birds with bills for probing, hammering, sipping, cracking and prying, filling roles that on a continent belong to a dozen unrelated families.
They are also the textbook example of what happens next. More than fifty species are known from the fossil and historical record. Around seventeen survive, most of those are threatened, several are critically endangered, and at least one has effectively vanished from the wild in the last few years.
This article is about where you can still find them.
The mosquito line, which explains all of it
Everything else follows from one fact. Hawaiian birds evolved with no exposure to avian malaria. The disease arrived in the nineteenth century when introduced mosquitoes met introduced birds carrying the parasite, and the honeycreepers had essentially no resistance; for several species a single infective bite is lethal.
Mosquitoes are limited by temperature and cannot complete their cycle above a certain elevation, and that created a refuge in altitude. Cold, high forest where mosquitoes could not breed is where honeycreepers survived, while every lowland population was wiped out. So the rule for finding these birds is simple and unforgiving: go up. Below roughly four thousand feet, the native forest bird community is largely gone.
The problem is that a warming climate moves that line upslope, and the amount of mountain above it is finite and shrinking. That is why landscape-scale mosquito suppression is being pursued in Hawaii with such urgency, and why several species have gone extinct while the tools were being developed.
Malaria is the headline and it is not the only cause, which matters because the other pressures are all still operating. Lowland forest was cleared for sugar, pineapple, ranching and settlement, removing the majority of the original range before malaria finished the job. Feral ungulates, meaning pigs, goats, sheep, cattle and deer, destroy understory and prevent regeneration, and in the case of pigs create the water-filled wallows in tree fern trunks where mosquitoes breed, which makes fencing and removal the single most effective ground-level management tool available. Rats take eggs and nestlings, cats take adults, and the small Indian mongoose takes both on the islands where it became established. Invasive plants outcompete the natives the birds depend on, particularly at forest edges. Avian pox, spread by the same mosquitoes, causes lesions and mortality alongside malaria. And Rapid ʻŌhiʻa Death now kills the foundation tree of the entire system, which is why Hakalau is closed to self-guided visits.
The reason to know all of that is that mosquito suppression alone will not be enough. It removes the acute killer. The fencing, predator control and replanting are what leave a forest for the birds to survive in afterward.
Hawaiʻi Island, the Big Island
The best remaining diversity, because it has the most mountain above the line.
Hakalau Forest National Wildlife Refuge, on the windward slope of Mauna Kea, holds the strongest populations of several species including ʻAkiapōlāʻau, Hawaiʻi ʻĀkepa and ʻAlawī, the Hawaiʻi Creeper. It is closed to self-guided visits because of Rapid ʻŌhiʻa Death, and access is only with one of five permitted commercial operators, so book months ahead. Hawaiʻi Volcanoes National Park, by contrast, is open and free to walk, and holds ʻApapane, Hawaiʻi ʻAmakihi and ʻIʻiwi in accessible ʻōhiʻa forest, with Kīpukapuaulu and the Mauna Loa Road area the standard spots. That is the easiest honeycreeper viewing in the state.
Beyond those, the Puʻu ʻŌʻō Trail off Saddle Road is state ground with high-elevation forest and a real chance of ʻAkiapōlāʻau without a permit, though it is harder work. Manukā and the Kona side hold ʻAmakihi and, historically, the very rare ʻAkiapōlāʻau and Palila on the dry side.
Palila deserves its own note. It survives only in māmane forest on the upper slopes of Mauna Kea, it is critically endangered, and its decline is tied directly to browsing by feral sheep and goats on the one tree it depends on. It has been the subject of long-running litigation over ungulate removal, which is an unusually direct illustration of how much of Hawaiian bird conservation is really a fencing argument.
Maui, Kauaʻi and Oʻahu
On Maui, Hosmer Grove in Haleakalā National Park is the classic roadside honeycreeper site in Hawaii and the easiest place in the state to see several species in a morning, with ʻIʻiwi, ʻApapane, Maui ʻAlauahio and Hawaiʻi ʻAmakihi all regular. Go at first light. Waikamoi Preserve, adjacent and managed by The Nature Conservancy, holds better forest and more species and is accessible only on guided hikes, which are worth arranging in advance. The Hanawī Natural Area Reserve on the remote windward slope holds Kiwikiu, the Maui Parrotbill, and ʻĀkohekohe, the Crested Honeycreeper, both critically endangered; it is not open to general access and these are not birds a visitor will see.
Kauaʻi is the most desperate situation, for a specific reason: it has no high mountain. Its summit is far lower than Maui's or the Big Island's, so there is very little forest left above the mosquito line at all. Kōkeʻe State Park and the Alakaʻi Plateau hold what remains, where ʻApapane and Kauaʻi ʻAmakihi are common, ʻAnianiau is regular, and Kauaʻi ʻElepaio, a monarch flycatcher rather than a honeycreeper, is confiding and reliable. ʻAkekeʻe and ʻAkikiki are critically endangered, and the ʻAkikiki has collapsed in the wild essentially to functional extinction, with the species' survival now resting on a captive population. Birders who watched them in the Alakaʻi twenty years ago were watching something that has gone in the interval. The Pihea Trail and the Alakaʻi Swamp Trail are the routes, both extremely muddy, on a plateau that is one of the wettest places on earth.
Oʻahu is the most degraded of the main islands and still not empty. ʻOʻahu ʻAmakihi and ʻOʻahu ʻElepaio persist in the Koʻolau and Waiʻanae ranges, reachable from the ʻAiea Loop Trail, Manoa Cliff and the Waʻahila Ridge area. The ʻAmakihi is notable for having apparently developed some malaria resistance and occurring at lower elevations than any other native forest bird, which makes it a species of real research interest.
The bills, and what they tell you
The reason this family is famous is worth seeing properly rather than merely ticking.
ʻAkiapōlāʻau has the most extraordinary bill of any American bird: a short straight lower mandible used like a chisel to hammer into wood, and a long thin decurved upper mandible used to probe the hole it has just made. One bird doing two woodpecker jobs with a single bill. ʻIʻiwi has a long, deeply decurved salmon-pink bill shaped for the tubular lobelioid flowers it co-evolved with, and since many of those plants are now extinct or nearly so, the bird has shifted largely onto ʻōhiʻa. ʻApapane has a shorter decurved bill for ʻōhiʻa blossom and is the generalist that has done best of any of them.
At the specialized end, Palila has a heavy finch bill for prying open green māmane pods, which is precisely why it cannot live anywhere those trees do not, and Kiwikiu has a heavy hooked bill for tearing into wood and bark after beetle larvae. The ʻAmakihi species sit at the other end with short, slightly decurved general-purpose bills, which is part of why they are the most adaptable and the most widespread survivors.
The pattern is the point. The more specialized the bill, the more precarious the bird. Generalists persist, and specialists tied to a single plant or a single technique are the ones on the critical lists.
Hawaii Acts to Prevent Honeycreeper ExtinctionWhat to expect on the ground
Set expectations correctly and the trip is a pleasure rather than a disappointment. The species list is short, and a good high-elevation morning might produce four or five native species, which is what an intact Hawaiian forest bird community looks like now. Introduced birds dominate everywhere below, and Japanese White-eye in particular is abundant in exactly the forest you are working while being superficially similar to a small honeycreeper at a glance.
The weather is against you, because windward high forest is wet, cold and cloudy, and a beautiful morning at sea level tells you nothing whatsoever about conditions three thousand feet up. Clean your boots, because Rapid ʻŌhiʻa Death moves in soil and is the direct cause of the Hakalau closure. And do not use playback, because these are small listed populations and drawing a territorial bird off a nest here is not a reasonable trade for a better view.
Saving Honeycreepers from Avian MalariaThe mosquito work, and why it is urgent
Since every part of this article depends on it, the intervention deserves explaining. The approach being pursued across Hawaii uses the incompatible insect technique, releasing male mosquitoes carrying a strain of a naturally occurring bacterium, Wolbachia, that is incompatible with the strain in wild females. Matings between them produce eggs that do not hatch, and released at scale and sustained over time this suppresses the mosquito population. It is not genetic modification, the released males do not bite, and the technique has been used against disease mosquitoes elsewhere.
The difficulty is scale: landscape-level release across remote, steep, wet, roadless terrain, sustained for years, delivered by helicopter and drone. And the urgency is arithmetic, because several Kauaʻi and Maui species have populations small enough that the difference between success and failure is a small number of years. ʻAkikiki already ran out of time in the wild, and Kiwikiu and ʻĀkohekohe on Maui are in the same position now.
For a visiting birder there is not much to do beyond understanding it, supporting the organizations doing the work, and cleaning your boots. But it is worth knowing that the forest you are standing in has an active plan attached to it rather than only a diagnosis.
The gear
Seeing honeycreepers means going high, into wet forest, usually with a guide, and the gear list has one item on it that is about the birds rather than about you.
Boots cleaned before you fly, and cleaned again between islands. Rapid Ohia Death is a soil-borne fungal disease that kills the tree these birds feed in, it has already killed ohia across large areas of Hawaii Island, and it moves on footwear and tires. This is the single most consequential thing on the list.
Close-focusing binoculars, because honeycreepers work blossoms in dense canopy at close range, and a pair that will not focus inside eight feet will show you a blur.
Full rain gear and warm layers, since the surviving populations are all at elevation on windward slopes, which is where the rain lands and where six thousand feet feels like six thousand feet.
A booking with a permitted Hakalau operator, if the Big Island is on the itinerary, made months ahead.
A camera with good high-ISO performance, since forest interiors are dark and these birds are quick.
Recordings for learning rather than for playback, which is the ethical line here and a sharper one than usual. These are critically endangered birds in small numbers and playback at them is not defensible.
And a land ownership map, because the accessible forest is a patchwork of national park, state forest reserve, private preserve and refuge, each with different rules about where you may walk.
Other native birds worth the trip
Honeycreepers dominate the discussion and Hawaii's other endemics deserve attention. ʻIo, the Hawaiian Hawk, occurs only on Hawaiʻi Island and is seen regularly over forest and even farmland on the Hilo side. Pueo, the Hawaiian Short-eared Owl, hunts by day over open country on several islands. ʻElepaio, a monarch flycatcher with distinct species on Hawaiʻi, Oʻahu and Kauaʻi, is confiding and curious and often the first native bird a visitor gets a proper look at. ʻŌmaʻo, the Hawaiian Thrush, is common in Volcanoes National Park forest and has a striking song. And Nēnē, the state bird, recovered from a low point of a few dozen birds and is now widespread on Kauaʻi, Maui and Hawaiʻi Island, frequently on lawns and golf courses.
Seabirds are the other half of Hawaiian birding entirely, with albatross, boobies, tropicbirds, noddies, shearwaters and petrels, most of them easier to see than the forest birds and several nesting where you can watch them. A week that includes forest, coast and a boat covers three completely different avifaunas.
The realistic itinerary
If you have one week, take the Big Island, with a booked Hakalau trip as the centerpiece and Hawaiʻi Volcanoes for the accessible species. If you have two, add Maui for Hosmer Grove at dawn and a Waikamoi guided hike. If you want Kauaʻi's endemics, go now rather than later, and understand what you are looking at while you do.
Hawaii is also one of the hardest access maps in the country, with national park, refuge closed to entry, state park, forest reserve, natural area reserve, Department of Hawaiian Home Lands, private preserve requiring a guide, hunting units open on some days and private ranch all adjacent and inconsistently signed. That layer is what Guidepole Bird carries, and here it is the difference between a forest reserve you may walk into and a two-hour drive to a locked gate.
And wherever you go, note the elevation you are standing at. That number is the whole story of these birds.
For the sites in detail, Hakalau Forest covers the permitted-guide system, and Kauai birding covers the Alakaʻi and the island's seabirds.
The refuge that holds the most intact remaining forest bird community, and how to get into it, is in Hakalau Forest National Wildlife Refuge. The island where the situation is most desperate is covered in birding Kauai. The playback question is treated properly in playback ethics, the access rules that govern a closed refuge are in a wildlife refuge is not a park, and the closure logic is in nesting and seasonal closures explained.
