Restoring Rare Birds on Maui
Endangered i'iwi on Ohia flowers (credit: Division of State Parks, Hawai'i)
The Hawaiian islands are known for many things: magnificent sunsets; a rich culture; amazing music and dance, as well as great surfing. What is less appreciated is the fact that the islands have the highest number of endangered species of plants, animals, and birds in the entire United States.
According to Hawaiian Department of Natural Resources, the islands are perhaps the most isolated archipelagos in the world. This isolation, created by their volcanic geology and resulting biogeography, reflects their unique location in the Pacific Ocean. 90% of the plants, animals, and birds are endemic to the Hawaiian archipelago. Hawai'i is home to sea turtles, the rare monk seal, dozens of marine seabirds, and a host of beautiful forest dwelling birds found nowhere else on Earth.
A group of rare birds evoloved on the Hawaiian islands, the Honeycreepers, which live in higher elevation forests of undisturbed stands of trees, including the native Ohia tree (Metrosideros polymorpha). These endemic birds carry names given to them by the native Hawaiians including the crimson i‘iwi; the black-billed ‘apapane; the green-yellow ‘amakihi; and the small brownish ‘elepaio. All of the Honeycreepers are threatened with extinction which is acute on islands, and explored in the book Song of the Dodo. That flightless bird once inhabited the island of Mauritius but went extinct in the middle of the 17th Century from introduced pests.
In Hawai'i, threats to the Honeycreepers are include deforestation for agriculture and tourism developments to the arrival of non-native mosquitoes. The tiny blood-sucking insects were brought unknowingly to Hawai'i on sailing ships from Europe and the US mainland in the 19th Century. The islands had no native mossies and the new arrivals carried a form avian malaria for which the birds had no resistance. With no resistance, a bird infected with the parastic disease can perish in a couple of day. Avian malaria, which doesn't infect people, immediately began to decimate the birds in the island's lowland forests. Birds at higher mountain forests were protected by the colder temperature where the mosquitoes could not reproduce. Now, climate change has passed that upper limitation and the disease is migrating upwards into those forests as well.
In an effort to reverse this situation, a program in habitat restoration has been initiated on Maui by ecologists in the hope to put extinction in the past. Sterile mosquitoes are being released which produce non-viable eggs when the insects breed with their wild malaria-carrying cousins in the higher elevation forests. If the releases are successful at a landscape scale, and mosquito populations are seen to significantly decline, the approach will be expanded to forests elsewhere in Hawai'i. Early indications in Haleakala National Park are look good and early evidence has also been detected that some level of genetic resistance to the disease. That could add another layer of protection for these rare birds.
A video was produced to document this proactive wildlife restoration effort and the people involved in trying to manae the recovery of forest habitat for Maui's birds.
Hopefully, the songs of these birds will continue being heard by hikers on mountain trails in Hawai'i rather than from field recordings. Like the dodo, the beautiful po'ouli is now extinct and will only be known from its once tape recorded song. WHB