Hawaiian honeycreepers are among evolution鈥檚 greatest examples of adaptive radiation, which occurs when one species diversifies into many to exploit a range of resources. But since the arrival of the first humans鈥攁nd especially since Europeans and Americans showed up and introduced mosquitoes鈥攖wo-thirds of the islands' honeycreepers have gone extinct. Only 17 species survive, including the Kiwikiu, a small olive-green passerine that wears a streak of yellow eyeliner and lives in the forests on the windward slopes of the Haleakal膩 volcano on Maui.
Now with only 150 Kiwikiu left and dire predictions that these birds will be wiped out within six years, scientists and officials are mounting another desperate effort to save the species. The problem is that not everyone agrees on the best plan, and the clock is ticking. 鈥We鈥re trying to make use of all the expertise available to us in order to make the best possible decisions at this point,鈥 says David Smith, administrator for the state鈥檚 Division of Forestry and Wildlife. 鈥淥ur likelihood of success is extremely slim.鈥
贬补飞补颈驶颈 is sometimes extinction capital of the world, and as such, heavy emotions pervade discussions around the Kiwikiu鈥檚 fate. The species鈥also known as the Maui Parrotbill鈥攐nce lived in low-elevation forests but many birds were killed off by mosquito-borne diseases, like avian malaria and avian pox. Those birds that remain lived in cooler forests above 4,000 feet, where mosquitoes once couldn't survive. Recently, however, climate change has been expanding the insects鈥 range鈥攁nd faster than anticipated. In 2019, after a decades-long effort by state agencies and private partners, 13 Kiwikiu were released on the leeward side of Haleakal膩 in hopes of establishing another population. But avian malaria killed almost all of them. A single mosquito bite is enough to transmit the deadly disease.
State officials have been working on a 鈥渕osquito birth control鈥 program that would curtail insect populations by releasing lab-raised mosquitoes that can鈥檛 produce offspring. But field trials won鈥檛 start until 2022 or 2023 and it鈥檚 uncertain how quickly they will be effective, if at all. The Division of Forestry and Wildlife is now considering a multi-pronged approach to buy time, which it submitted in March in an informational briefing to the state's Board of Land and Natural Resources. It involves leaving some birds in their wild habitat, while possibly translocating others to 贬补飞补颈驶颈 Island, where higher elevation mountains safely harbor other honeycreepers. But there鈥檚 no evidence that Kiwikiu historically lived there, and so how they鈥檒l fare there or interact with other birds is unknown.
According to the informational briefing, another option involves bringing 20 to 30 birds to facilities in Virginia, Pennsylvania, and Utah, where they might remain until their habitat can be made malaria-free. But when a species is so close to the edge, tensions are common over whether bringing individuals into captivity is the right course of action. Not doing so may risk complete extinction. However, removing individuals from a remaining small breeding population may hasten extinction in the wild, and it鈥檚 often unclear if captive animals will be able to return to their natural habitats, especially if they lose their natural behaviors or their genetic diversity becomes too limited.
In the case of the Kiwikiu, all of these concerns are in play. That's why a 25-year-old Native Hawaiian ornithologist, Bret Nainoa Mossman, has prompted a broader debate. After reading about the state鈥檚 briefing in, Mossman started a against bringing birds into captivity and shared it on his popular and pages, which are dedicated to 贬补飞补颈驶颈鈥檚 birds. He believes it is too big a risk to take the birds into captivity, especially to zoos that are on the mainland. He worries that being separated from the land and its native plants will negatively impact Kiwikiu鈥攖hey could die in transit, may lose cultural knowledge, and may not be able to return to their natural habitat. 鈥淧lace is so important because it鈥檚 where our culture is rooted, and the same thing for the birds鈥攖hey develop their behaviors and their songs based on where they live,鈥 he says.
Mossman feels a kinship with Hawaiian birds. He grew up in Utah, but he went to a summer school program in 贬补飞补颈驶颈 run by Kamehameha Schools, where he learned about Hawaiian culture. In college, he returned to work with captive Palila, another endangered honeycreeper, and then moved to 贬补飞补颈驶颈 Island for a conservation biology master鈥檚 degree. Today he lives with cousins on Hawaiian Homelands, which are reserved for people of Hawaiian descent.
Patrick Hart, a behavioral ecologist at the University of 贬补飞补颈驶颈 at Hilo who served as Mossman鈥檚 thesis adviser, agreed with Mossman鈥檚 concerns. He noted the importance of 鈥渃ultural transfer鈥 between Kiwikiu, similarly to how humans pass along knowledge. This is how the birds learn to find food, avoid predators, sing mating songs, feed their young, and so much more. 鈥淚t鈥檚 really important to keep that cultural flow of knowledge going,鈥 said Hart. Whether in the wild or in a facility, he says, 鈥淚鈥檇 rather see them stay here.鈥
In the wild, Kiwikiu forage across large expanses. While hard to spot in the subcanopy, they sometimes give away their location with crunching sounds as they use their parrot-like bills to dig insects out of the bark of native plants, like the 驶艒hi驶a lehua. They have long lifespans, living up to 18 years, and the chicks spend a year and a half with their parents before venturing out on their own. In prior attempts to captive-breed the Kiwikiu, the birds have rarely mated and never raised their own offspring, forcing humans to hand-rear the few chicks born. Right now, the state is looking at captivity mainly as a measure to keep some surviving birds safe from mosquitoes. The goal isn鈥檛 necessarily to breed them or create a zoo population, says Smith.
Many captive-reared birds from Hawaiian forests, such as the 驶Alal膩, 驶Alaw墨, 膧kepa, and Palila, have struggled after their release, Mossman notes. While some have lived for a few years in the wild, none have resulted in populations in the wild today. (Representatives with the two bird conservation centers in 贬补飞补颈驶颈 where previous captive-bred programs took place, Maui Bird Conservation Center and Keauhou Bird Conservation Center, declined to be interviewed.)
Asked about some of Mossman's objections, Smith said: 鈥淭hese are all valid concerns鈥攖here's no question about it, and that's why it is a very difficult decision.鈥 Smith said that officials are currently looking at whether a facility in 贬补飞补颈驶颈 would be able to keep one-third of the birds, rather than bringing them all to the mainland. A final proposal will be submitted within months to the Board of Land and Natural Resources for approval, he says.
Since starting the petition, Mossman says he has heard from some other Native Hawaiians who offered support. According to a 2010 census, nearly half of the 527,000 people who identify as Native Hawaiian live on the continent, in part, he notes, because of the high cost of living on the islands. 鈥There is this deep connection to 贬补飞补颈驶颈 for Hawaiians. The 膩ina is what gives us life,鈥 said Mossman, referring to the land. 鈥淏eing separated from that, we can survive, but we don't do as well as we could, and I think that's why [this issue] connects so much with people, because they felt that pain.鈥