Nā Manu Nahele
The Native Forest Birds
Hawaiʻi is a unique archipelago, with incredible geology, culture, and biodiversity. More than 90% of native plants and animals are found only in Hawaiʻi and nowhere else on Earth. These unique species are deeply connected with Hawaiian cultural practice and identity. Since human arrival in Hawaiʻi, 71 of the original 115 bird species found here have become extinct: 48 prior to the arrival of Europeans and 23 since Captain James Cook’s arrival in 1778.
Hawaiʻi is internationally renowned for the incredible and unique species found only here, including native forest birds like the endangered Hawaiian honeycreepers. The Hawaiian honeycreepers are small native forest birds in the finch family. They coevolved with native Hawaiian plants and are integral in maintaining the health of native Hawaiian forests. Some honeycreepers help pollinate, while others eat grubs and insects from tree bark.
The Hawaiian honeycreepers are considered to be one of the most diverse groups of birds in the world. Historically, more than 50 different species of honeycreepers lived in Hawaiʻi – filling the forests, from mountains to sea, with their songs. But today, only 17 species remain; 15 throughout the main Hawaiian islands. Many are nearing extinction.
“Before we were working on recovery, but now we need to prevent extinction.”
Lisa 'Cali' Crampton
Kauaʻi Forest Bird Recovery Project
Populations in Decline
The remaining Hawaiian honeycreepers’ populations have been declining due to habitat loss, increased predation by non-native species, and the effects of avian diseases spread by invasive mosquitoes. Habitat loss and degradation have been caused by human activities, water diversion, weeds, and invasive species like ungulates (non-native hooved animals such as pigs and goats) and mosquitoes.
Mosquitoes were introduced to Hawaiʻi in 1826 and began to spread avian diseases in the early 1900s. Avian malaria, now the biggest threat to the Hawaiian honeycreeper, is a blood-borne parasite passed to birds through mosquito bites. The Hawaiian honeycreepers evolved without exposure to avian diseases, so the birds have little to no natural resistance to them. This leaves the birds incredibly vulnerable to the effects of avian malaria and pox. For many honeycreepers, a single bite from a mosquito infected with avian malaria could be fatal. But the spread of avian diseases began in the early 1900s, why are the effects getting worse now?
Until recent history, honeycreepers were relatively safe from mosquitoes because of physical separation. Mosquitoes live in warm areas which usually occur at low elevations. Honeycreepers live in high-elevation forests where temperatures are usually too cool for mosquitoes. But the effects of climate change are increasing the temperatures in high-elevation forests, making them a more habitable area for mosquitoes. This is directly increasing the transmission of avian diseases like avian malaria.
Without intervention, this disease will directly cause the extinction of some species of Hawaiian honeycreeper.
The protection of the remaining native birds in Hawaiʻi, especially the increasingly rare honeycreepers is considered to be the highest bird conservation priority in the United States and in Hawaiʻi.