I cannot conclude my blogs on the U.S. State of the Birds Report without mentioning Hawaii and its birds. The native bird species of Hawaii are by far in the worst shape of any group of birds in the United States.
Here’s why the severe decline in Hawaii’s birds should be an issue of national concern:
- One-third of all federally listed bird species in the United States occur in Hawaii.
- More than 65 percent of Hawaiian birds are federally endangered or threatened or are otherwise of conservation concern.
And all of these depressing numbers do not include the 71 species known to have gone extinct since human colonization of the islands about 1,700 years ago. This is without a doubt the single most important bird conservation issue in our country today, yet does not receive nearly the attention it deserves.
While habitat loss is a key threat to Hawaiian birds, the biggest problem on Hawaii (as well as other islands in the world) is introduced, invasive species.
The invaders come in several forms:
- Introduced plants that change and degrade the native habitat;
- Non-native animals that either kill birds directly or modify their habitat;
- And (most insidiously) introduced diseases spread by introduced insects that are fatal to most native birds.
The cumulative impacts of these invasives, particularly introduced avian malaria, mean that most native Hawaiian birds are restricted to higher elevation forests where disease carrying mosquitoes do not occur. However, even these last refuges are now under potential threat from climate change, which may allow mosquitoes to invade every higher elevations.
Efforts at invasive species exclusion, reforestation and removal of non-native plants in some areas of Hawaii suggests that there are some reasons for optimism for such species as the ‘Akiapola’au, which has shown positive responses to such efforts. Translocation of the Laysan Duck to Midway Atoll appears to have resulted in the creation of a second population to provide extra insurance against catastrophes. The eradication of rats from Midway Atoll has led to a veritable population explosion of Bonin and Bulwer’s Petrel and Tristram’s Storm-Petrel. These are all extremely encouraging developments and indicate what could happen if we applied sufficient time and resources to this urgent problem.
Yet, it is undeniably true and a national tragedy that irreplaceable components of our biological heritage have already been lost — many extremely recently. Such fascinating products of the Hawaiian laboratory of evolution as the ‘O’u, Nukupu’u, O’ahu ‘Alauahio, Maui ‘Akepa and Po’ouli are all thought to have gone extinct in the last two decades of the 20th century. They live now only as museum skins, photos, illustrations, sound recordings, and in the memory of those who studied them.