One of the last two locations where the critically endangered Hawaiian honeycreeper ‘Akikiki lives has lost nearly all of its birds this year. And the wild population for the species overall is reported to be fewer than 100 but more likely below 50.
The small gray-brown and white bird occurs only in montane rainforests on Kaua‘i, the northernmost of the main Hawaiian islands. Fifty years ago, it numbered more than 6,800 individuals, but habitat loss, a 1992 hurricane, and mosquito-borne avian malaria have taken a huge toll. In 2012, the species was estimated to total 468 birds. If the number in 2021 is indeed below 50, that would mean the ‘Akikiki has lost about 90 percent of its population in just nine years.
A field site in the central mountains known as Halehaha that was home to 70 birds in 2015 now hosts only four or five. This week, a six-person rescue crew is in the field attempting to capture the handful of remaining birds to take them to a breeding program on Maui, where they would join about 40 captive-reared members of their species.
Four of the remaining birds at Halehaha are a breeding pair and their chicks. If the birds are found, they’ll be flown by helicopter to the Maui Bird Conservation Center operated by the San Diego Zoo Wildlife Alliance. Surveys at Halehaha have shown a recent increase in invasive mosquitoes that carry avian malaria and other diseases. Moving the remaining birds is a decision of last resort and likely the only way to keep the population from death.
“In 2018, we had territories and nests everywhere,” said Cali Crampton, the leader of the Kaua‘i Forest Bird Recovery Project (KFBPR) and the head of the search and rescue mission. “This year we were able to only find one nesting pair and we believe there are only four, maybe five, ‘Akikiki left in this entire area. When I first started with the project, there were more than 100.”
Extinction for honeycreeper potentially just a few years away
Avian malaria is killing the highly susceptible honeycreepers one by one. During an exercise earlier this year, four experts in the field were tasked with analyzing all the available data. They were asked to come up with current ‘Akikiki population estimates and a time to extinction for the diminutive birds. They concluded the population of ‘Akikiki as less than 100 and probably fewer than 50. Most disturbing was their finding that absent landscape-scale control of disease-carrying mosquitoes, ‘Akikiki could be extinct in little more than two years. “I think these are desperate times. Ten years ago, there were more than 70 breeding pairs,” Crampton noted.
One other wild population that is nearby “seems to be doing better” than the Halehaha group, according to Dan Dennison, a spokesperson for the Hawai‘i Department of Land and Natural Resources.
“I hoped we wouldn’t be here,” Crampton said. “I also know we were hoping against hope when we started the conservation breeding flock with the egg collections. We wanted to have mosquito control in place before they invaded here. Unfortunately, we are out of time for this particular species and this particular field site.”
Birds Not Mosquitoes
Meanwhile, many state and federal agencies and conservation nonprofits are working on plans to introduce sterile mosquitoes into the Kaua‘i forests and other places in Hawai‘i where avian malaria is devastating populations of numerous native forest birds, bringing them closer to extinction. They formed a partnership called Birds Not Mosquitoes, which is working on the potential for a bacterium to act as a mosquito birth control. The tool, also known as Incompatible Insect Technique, is one of several that biologists could use to reduce the impacts of invasive species. With their forests in better condition, experts foresee a future when Halehaha’s ‘Akikiki could return home.
However, that goal is nowhere near reality. Dennison said that implementing mosquito controls in the wild is likely “several years out.”
Peter Luscomb of the nonprofit Pacific Bird Conservation has decades of experience with bird translocations around the world. He’ll be responsible for feeding and caring for the ‘Akikiki the rest of the team hopes to capture, and he’ll treat them for avian malaria. “I think it’s critical,” he said of the attempt to capture the remaining birds. “The population is crashing, and if these birds are left out in the forest, all indications are, they will die.”
Justin Hite, KFBRP’s field supervisor, and other team members blame climate change for the near demise of the ‘Akikiki. “This is the last, best place for native birds on Kaua‘i. Many organizations and individuals have worked hard for many years to create a perfect area…a last refuge for birds in an almost entirely intact native forest,” he said. “These birds remain in the very top, thin layer of the island. As the climate is warming, it’s made this last, little, teeny piece of Kaua‘i as good mosquito habitat. Unfortunately, this area is no longer safe for these birds.”
He added that what’s happening to the ‘Akikiki is coming for the other Hawaiian birds. “The forest is so silent now and it’s about to become more silent.”