Urgent Intervention Could Save Critically Endangered Hawaiian Honeycreeper.

A recent collaborative study led by the San Diego Zoo Wildlife Alliance, Smithsonian’s National Zoo & Conservation Biology Institute, and other researchers sheds new light on the critical extinction threat faced by native Hawaiian forest birds, particularly the Hawaiian honeycreepers. Despite the alarming population declines, the study provides a cautious optimism: with immediate and effective intervention, recovery of the critically endangered ‘akeke’e is still achievable.

The study identifies avian malaria as the primary cause behind the drastic declines of the ‘akikiki and ‘akeke’e species, both endemic to Kaua’i island. These declines, exceeding 99% over the last twenty years, coincide with the spread of avian malaria during the late 20th century. As the disease-carrying mosquitoes advance higher into mountainous habitats due to warming temperatures, these birds lose their remaining safe refuges, exacerbating their vulnerability. Kaua’i’s lack of high-elevation environments makes this problem particularly severe.

Currently, fewer than 100 ‘akeke’e remain in the wild, while the ‘akikiki is considered extinct in its natural habitat. The only hope for the ‘akikiki now lies within a conservation breeding program housing about 40 individuals at the Maui and Keauhou Bird Conservation Centers, managed by the San Diego Zoo Wildlife Alliance. Efforts to combat the spread of mosquitoes, including releasing reproductively incompatible males to reduce mosquito populations, are underway as a critical component of the species’ survival strategy.

One promising discovery from the study is that Hawaiian honeycreepers retain surprisingly high genetic diversity despite their critical status. Even the last known po’ouli—a species declared extinct—showed significant genetic variation. This diversity could enhance the birds’ ability to adapt to environmental threats. However, it also brings risks, as rapid population declines increase the chance of inbreeding depression, which negatively impacts survival and reproduction.

Indeed, inbreeding depression has already been detected in the ‘akikiki population. The research reveals that many individuals in the captive breeding program are offspring of closely related parents, resulting in fewer offspring and lower survival rates. These findings will be instrumental in guiding future breeding decisions, helping to select mates more strategically to reduce the effects of inbreeding.

The research further highlights the value of biobanking for conservation. In 2004, the San Diego Zoo Wildlife Alliance successfully cryopreserved cell lines from the last living po’ouli, marking the first time viable material from an extinct species was preserved in the Frozen Zoo. Recently thawed samples have provided valuable genomic data, offering insights into the evolutionary history of Hawaiian honeycreepers and informing ongoing conservation efforts.

Oliver Ryder, Ph.D., director of conservation genetics at San Diego Zoo Wildlife Alliance, reflected on the significance: “We will never hear the po’ouli honeycreeper’s song again, but we can learn from its genetic code.” These genomic insights provide a crucial understanding of the challenges facing these birds and how to best support their survival.

Christopher Kyriazis, Ph.D., lead author and postdoctoral researcher, emphasized the urgency: “In a race against time to save the remaining honeycreepers, necessary insights about their survival are found in their genetic makeup. Our findings provide a new understanding of the last remaining individuals as recovery efforts forge on both in their native forests and in human care.”

With fewer than 17 of approximately 60 native Hawaiian honeycreeper species remaining—and most experiencing rapid declines—the study serves as a vital call to action. Success in mosquito control and careful genetic management may still secure a future for the ‘akeke’e and ‘akikiki, but the window for intervention is closing fast.

Source:https://phys.org/news/2025-05-recovery-critically-endangered-hawaiian-honeycreeper.html

This is non-financial/medical advice and made using AI so could be wrong.