Heart of 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; and great surfing. What is less well known is the fact that the islands have the highest rates of endangered species of plants, animals, and birds in the United States.
According to Hawaiian Department of Natural Resources, the islands are one the most isolated archipelagos in the world. This isolation, created by their volcanic biogeography, reflects their unique place in the tropical Pacific Ocean. Hawai'i is home to sea turtles, a rare endemic seal, dozens of seabirds, and a host of beautiful forest birds found nowhere else on Earth. 90% of the plants, animals, and birds are endemic to the archipelago. The birds are found within higher elevation forests where undisturbed stands of native trees, like the Ohia tree (Metrosideros polymorpha), remain. They include the crimson i‘iwi honeyeater; the black-billed ‘apapane; the yellow-green ‘amakihi; and the small brown ‘elepaio.
These endemic birds are all threatened with extinction. The threat is particularly acute on islands and was explored in depth by the book Song of the Dodo, the iconic flightless bird that once inhabited the island of Mauritius. In Hawai'i, the threats are multiple and due to deforestation for agriculture and tourism developments to the arrival of non-native mosquitoes. The tiny blood-sucking insects were brought unknowingly to Hawai'i by sailing ships from Europe and the US mainland in the 19th Century. Since the islands had no native mossies, the new arrivals carried a form malaria for which the birds had no resistance. Having no resistance, an infected bird will perish in a matter of hours. Avian malaria, that doesn't infect people, began to decimate the native birds in the island's lowland forests. The birds in mountain forests were protected by a cold temperature line where the mosquitoes could not reproduce. Now, climate change has passed that upper limit into higher elevations and the disease has migrated upwards to those forests as well.
In an effort to reverse this situation, a program in habitat restoration in Haleakala National Park has been initiated by ecologists who hope to put extinction in the past. Sterile mosquitos have been released which produce non-viable eggs when they breed with the wild malaria-carrying insects existing in the high elevation forests. If the releases are successful at a landscape scale, mosquito populations should rapidly decline, and the approach will be expanded to forests elsewhere in Hawai'i. A video was produced to document this unique project and the people involved in trying to restore and expand the habitat for the endemic 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 taped song. WHB