Iconic Hawaiian Bird Threatened by Malaria
by Ramona Young-Grindle, Court House News, September 21, 2016
WASHINGTON (CN) - The Fish and Wildlife Service Tuesday proposed the 'i'iwi, a Hawaiian honeycreeper, for Endangered Species Act protection as a threatened species, due to introduced avian malaria. Hawaiian birds evolved in the absence of mosquitoes, so they do not have natural immunity to the diseases brought in by introduced mosquitoes, such as avian malaria, which kills about 95 percent of the birds infected with it, according to the agency.
"Mosquitoes are wreaking havoc on the 'i'iwi and other native bird populations in Hawaii, and the Service is continuing to search for a solution to the problem so we can save these species that play such an important role in making Hawaii such a special place," Mary Abrams, FWS field supervisor for the Pacific Islands said. "We all must be diligent in the search for a solution to the mosquito problem that affects humans and animals alike."
The Center for Biological Diversity conservation group petitioned on behalf of the 'i'iwi in August 2010. Due to other listing and funding priorities, the Service did not complete the 90-day review of the petition until 2012. The action published Tuesday constitutes both the listing proposal, and the 12-month status review, which was also greatly delayed from the statutory deadline of 12 months from receipt of the petition.
"The 'i'iwi is a spectacular, iconic Hawaiian bird that desperately needs Endangered Species Act protection to survive," the Center's Loyal Mehrhoff said. "But the good news is that if we protect it, it has a good shot at dodging extinction. A recent study by the Center found that the majority of U.S. birds with endangered species protection are improving."
The 'i'iwi was once common on all the major islands in the Hawaiian chain, and was found from sea level to the tree line. Today, the birds are found mostly on the Island of Hawaii (the big island), east Maui and Kauai, in the forests roughly between 4000 ft and 6000 ft where cooler temperatures discourage the mosquitoes. "The present distribution of 'i'iwi corresponds with areas that are above the elevation at which the transmission of avian malaria readily occurs," the agency said. Ninety percent of the birds are found on the Island of Hawaii, with less than one percent found on Kauai.
Development and transmission of the malaria parasite are limited by temperature, becoming more prevalent in warmer temperatures. "The extent and impact of avian diseases upon 'i'iwi are projected to become greatly exacerbated by climate change during this century," the agency said.
The 'i'iwi are primarily nectar eaters, with a diet occasionally supplemented by insects and spiders. Their nectar needs are derived mainly from the flowers of the ohia tree, mamane, and various plants in the lobelia family. On the big island, where 90 percent of the 'i'iwi live, a tree disease called rapid ohia death is adding to other stressors on the birds by reducing habitat in the already narrow disease-free zone where they live and forage.
"Protected areas that we once thought could save the 'i'iwi are now expected to be uninhabitable in the future because of the expanding range of mosquitoes and malaria," Mehrhoff said. "So it's crucial for the 'i'iwi to get the help it needs to avoid extinction and recover. This will require removing or greatly reducing the threat from introduced mosquito-borne diseases, as well as restoring and protecting native Hawaiian forests."
The agency has determined that it needs additional time to identify specific areas appropriate for a critical habitat designation due to the complexities of projected climate change effects, according to the action.
Comments and information regarding the listing proposal are due by Nov. 21.