For Immediate Release, August 24, 2010
Contact: Noah Greenwald, (503) 484-7495
Endangered Species Act Protections Sought for Four Mountaintop Species
Threatened by Climate Change
PORTLAND, Ore.— The Center for Biological Diversity today filed petitions to protect four mountaintop species, from Hawaii to New Hampshire, that are threatened by climate change, including the ‘i‘iwi, a Hawaiian songbird; the white-tailed ptarmigan, a grouse-like bird of the Rocky Mountains; Bicknell’s thrush, a northeastern U.S. songbird; and the San Bernardino flying squirrel of Southern California. All four are limited to high-elevation mountaintops, where a shifting climate threatens to eliminate their habitat.
“Climate change will have disproportionate impacts on species that live at high elevations,” said Noah Greenwald, endangered species program director at the Center. “These four species are literally going to be pushed off the top of the mountain.”
Mountaintop species are particularly vulnerable to climate change because as the climate warms, they have nowhere to go. The ‘i‘iwi was once widespread throughout the Hawaiian Islands, but is now restricted to high-elevation areas on the Big Island and Maui because of the spread of avian pox and malaria by mosquitoes, which are already moving uphill with a warming climate. Bicknell’s thrush is jeopardized by the loss of its native high-elevation forests due to warming, as well as acid rain damage to red spruce. With its extensive adaptations to cold, snowy climates, the ptarmigan is threatened by warmer winter temperatures and forests that will creep uphill and eliminate its alpine habitat. Finally, the San Bernardino flying squirrel is thought to have already disappeared from one of the two mountain ranges where it lives; the remaining isolated population is threatened by the upward movement of its forest habitat and increasing drought that threatens its food supply.
“The plight of these four species shows that global warming is causing widespread harm, here and now, across the United States,” said Shaye Wolf, a Center biologist. “If we don’t rapidly reduce greenhouse gas pollution, scientists predict that one third of the world’s species will be condemned to extinction by 2050.”
Changes in climate are already apparent in many mountainous areas. Studies from the western U.S., for example, have documented reduced snowpack and earlier spring runoff. These changes will mean less and warmer water in the summer months in many areas, with impacts to both people and wildlife. The Center’s scientific petitions request that all four species be protected under the Endangered Species Act.
Background on the species
‘I‘iwi: With its fiery-red body, quick black wings and long, curved, salmon-colored bill, the ‘i‘iwi — or scarlet Hawaiian honeycreeper — is one of the most recognizable birds of Hawaii. Although it was once widespread across the islands, this iconic bird is now in danger of immediate or near-term extinction across the whole western portion of its habitat. The spread of avian malaria and avian pox has limited its range to high-elevation areas where it’s too cool for mosquitoes to deliver the diseases. As climate change pushes colder temperatures farther and farther upslope, the bird will have fewer and fewer high-mountain refuges — and will eventually run out of room altogether.
Bicknell’s thrush: The drab brown coloration of the Bicknell’s thrush hides a highly unusual songbird with an extremely limited geographic range. It breeds only at higher elevations in the northeast United States and eastern Canada and winters on a handful of islands in the Caribbean, primarily the Dominican Republic. Males outnumber females 3 to 1, and most females mate with multiple males, who then share in the job of provisioning for nestlings. This uncommon domestic arrangement helps ensure reproductive success for a species that has chosen to live in an often harsh environment marked by late springs, cold and fog. As the climate warms, the range of hardwoods appears to be rapidly moving up in elevation, supplanting the coniferous trees the thrush depends on for nesting. With increased temperatures, new predators, competitors, and diseases are likely to move up into the thrush’s habitat as well, further stressing a species that is being squeezed out of its mountain home.
White-tailed ptarmigan: The smallest bird in the grouse family, the white-tailed ptarmigan is also one of the few animals that lives on alpine mountaintops throughout its entire life. Every part of this ptarmigan is adapted to help it thrive in a frigid climate, from its feathered, snowshoe-like talons to its seasonally changing plumage to its remarkable metabolic ability to gain body mass throughout harsh winters. But as the climate warms, these same adaptations could spell the bird’s doom. The ptarmigan’s range is severely limited by its sole dependence on alpine habitat, which is shrinking as hotter temperatures sneak up the mountainsides, threatening to push the tree line — and the ptarmigan — to ever-higher elevations, until there’s no more room to rise.
San Bernardino flying squirrel: A subspecies of the northern flying squirrel, the San Bernardino flying squirrel is distinguished by the parachute-like panels of skin that stretch from wrist to ankle, allowing it to glide for 300 feet or more between trees. The flying squirrel lives year-round in high-elevation conifer forests of Southern California, and like the spotted owl, appears to thrive in mature forests with big trees, large snags, and plenty of downed logs that foster the growth of the truffle fungi they eat. The San Bernardino flying squirrel is thought to have disappeared from the San Jacinto Mountains in the past few decades, and the remaining population, which is isolated to the upper-elevation forests of the San Bernardino Mountains, faces numerous threats. With climate change, the squirrels’ forest habitat is moving upslope as temperatures warm; drought threatens its truffle fungus food, which depends on wet, cool conditions. Forest-management practices that remove canopy cover, snags and downed logs are degrading the squirrel’s habitat, and ever-increasing urban development is encroaching on its mountain home.