As environmental impacts unfold in Hawaii, I’iwis’ seasonal migrations turn deadly.
The scarlet I’iwi is hard to miss, standing out vibrantly against the deep green backdrop of Hawaii’s foliage. The native bird, a Hawaiian honeycreeper, fits gracefully into its natural habitat. Its curved bill, for example, matches the shape of the native ‘Opelu flower, which makes for easy nectar-sipping. But as environmental impacts turn the seasonal migrations deadly, the I’iwi, classified Vulnerable on the International Union for the Conservation of Nature Red List, is at risk of extinction.
Mosquitoes, feral pigs, and climate change
Avian malaria was introduced to Hawaii around 1826. The disease is carried by mosquitoes and is deadly to many of Hawaii’s birds. Avian malaria is thought to be the most urgent threat facing the I’iwi, which is being considered for listing under the Endangered Species Act. Today, invasive feral pigs and climate change are creating conditions that favor mosquitoes and put I’iwi at higher risk.
Avian malaria is spreading in Hawaii as the islands become increasingly hospitable to mosquitoes. Mosquitoes need standing water to lay their eggs; feral pigs dig wallows, which collect water and turn into stagnant muddy pools–very attractive to mosquitoes looking to lay eggs.
Meanwhile, the range of suitable habitat for mosquitoes in the region is expanding. Human-induced climate change is causing temperatures to rise globally–including in Hawai’i. I’iwi populations in the lowlands are disappearing as a result of Avian malaria. These and other native birds of Hawaii are more likely to avoid contracting avian malaria when they are in the higher, cooler regions of Hawai’i. However, this mosquito-free range is ever-shrinking as temperatures rise.
Of all the honeycreepers that have been tested, I’iwi are the most vulnerable to Avian Malaria. Current optimistic projections hold that I’iwi will be on the verge of extinction shortly after the turn of the century.