Kiwikiu Recovery

The kiwikiu (Maui Parrotbill; Pseudonestor xanthophrys) is a critically endangered Hawaiian honeycreeper found only on the island of Maui. Once common across both Maui and Moloka‘i, this rare forest bird now survives in just 20 km² of wet rainforest on the windward slopes of East Maui.

A Shrinking Range

Fossil evidence shows kiwikiu once inhabited a variety of forest types—from lowland dry forests to high-elevation rainforests. Today, they’re restricted to remote, mosquito-limited habitats above 5,500 feet (1,600 meters), including:

• The Nature Conservancy’s Waikamoi Preserve
• The State’s Hanawī Natural Area Reserve
• Haleakalā National Park’s Kīpahulu Valley and Manawainui Planeze

Threats to Survival

Like many native Hawaiian forest birds, kiwikiu face a suite of severe threats:

• Habitat loss from past deforestation, agriculture, and invasive species
• Introduced predators (e.g. rats, cats, mongoose)
• Avian malaria spread by mosquitoes—now expanding into high elevations due to climate change

Species Status: Endangered

The kiwikiu population has declined dramatically in recent decades:

• 1980: ~500 individuals
• 2017: 44–312 individuals
• 2022: 20–168 individuals
• ~44% decline between 2017–2022

Current rates of reproduction and survival are not enough to sustain the population. Without major intervention, extinction is possible within 5 years.

Even though the remaining habitat is protected, rising temperatures and mosquitoes are pushing the species closer to the brink. By 2100, suitable habitat could shrink to just 7 km².

What We’re Doing to Help

Research & Monitoring

Since 2006, the Maui Forest Bird Recovery Project (MFBRP) has studied kiwikiu behavior, reproduction, and survival. Our findings include:

• Long-lived species (15+ years) with strong pair bonds
• One chick every 1–2 years, with high juvenile mortality
• Large home ranges (~9 hectares) and low nest success due to predators and weather
• High adult survivorship, but limited recruitment

We also collect genetic samples to guide future conservation breeding and translocation efforts.

See Research and Publications.

Translocation & Lessons Learned

To prevent extinction, the U.S. Fish and Wildlife Service (USFWS) Recovery Plan (2006) called for establishing a second population. Nakula Natural Area Reserve, on the leeward slope of East Maui, was selected and restored through: forest recovery (fencing, ungulate removal, native planting). Research was conducted on arthropod (food source) surveys and mosquito and predator control was implemented.

In 2019, we translocated 14 kiwikiu (7 wild, 7 from captivity). Unfortunately, most died from avian malaria, as mosquito levels were 28 times higher than normal due to unusually warm, dry conditions.

Despite the loss, this effort proved that kiwikiu can survive in Nakula—if disease is controlled. Additionally, one wild male kiwikiu survived and returned to his original capture location.

Read the 2019 Kiwikiu Conservation Translocation Report here.

The Path Forward

Following the failed translocation, we collaborated with experts to reassess conservation priorities. Key strategies now include:

1. Deploying the Incompatible Insect Technique (IIT) to suppress mosquito populations
2. Establishing captive care programs to safeguard against extinction
3. Exploring translocations to higher-elevation refugia, including Hawai‘i Island
4. Integrating Native Hawaiian knowledge into conservation practices
5. Developing next-gen tools to address threats at scale

Mosquito suppression is now the top priority for preventing extinction in the wild.

Conservation Breeding

The Hawaiian Endangered Bird Conservation Program, led by San Diego Zoo Wildlife Alliance, manages captive populations at:

• Maui Bird Conservation Center
• Keauhou Bird Conservation Center (Hawai‘i Island)

The original captive population, started in 1997, was small and nearly all individuals were used in the 2019 translocation. In 2024, we began building a new conservation breeding program with wild-caught individuals to ensure we have a viable population ready for future release once mosquito threats are reduced.

Learn More