Endangered Species Act Protections Sought for Four Mountaintop Species Threatened by Climate Change

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.

https://www.biologicaldiversity.org/species/birds/iiwi/index.html

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.

https://www.biologicaldiversity.org/species/birds/Bicknells_thrush/index.html

https://www.fws.gov/northeast/climatechange/stories/bicknellsthrush.html

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.

https://www.biologicaldiversity.org/species/birds/white-tailed_ptarmigan/index.html

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.

https://www.biologicaldiversity.org/species/mammals/San_Bernardino_flying_squirrel/index.html