Scientists believe the American pika, a mountain-dwelling relative of the rabbit, is heading for extinction and will be one of the first mammals to fall victim to climate change.
Ochotona princeps, a stocky tail-less animal about the size of a hamster, lives between the tree-line and mountain peaks.
As the climate heats up it is having to go to higher altitudes to find suitable habitats.
In the winter it lives under the snow in tunnels, feeding off piles of hay it has stored inside.
A study reported in the US Journal of Mammalogy found that in pika populations at 25 places nearly 30% of the animals had gone. The locations are so remote that there seemed to be no other factor than climate change.
The study between 1994 and 1999 surveyed the sites in the Great Basin, east of Sierra Nevada and west of the Rocky Mountains, where pikas had been recorded.
Although the habitat had apparently changed little in that time, pikas had vanished from seven of the 25 places during the past 86 years: a period shown by the data to have experienced climate change.
Research shows that American pikas are particularly vulnerable to global warming because they live in areas with a cool, fairly moist climate.
They are active above ground in the early morning and retreat to their nests in rock crevices shortly after sunset.
"Losses of pikas are disturbing because pikas are often locally abundant and scientists had assumed that alpine and sub-alpine ecosystems were relatively undisturbed because of their isolation," said Erik Beever of the US geological survey's forest and rangeland ecosystem science centre, the lead author of the report.
"The responses of pika populations are a signal of the impacts of climate change in alpine and sub-alpine systems."
Many northern hemisphere mountain animals are expected to migrate north or seek higher ground to find suitable habitats as the climate alters. But the American pika appears not as well-equipped as other species to handle this environmental shift.
"American pikas are like the canary in the coal mine," said Caterina Cardoso, head of WWF-UK's climate change programme.
"Their disappearance is a red flag that our heavy reliance on dirty fossil fuels, such as coal and gas, is causing irreparable damage to our environment. We must switch to clean, renewable energy resources before it's too late for us and the pika."
© Guardian Newspapers Limited 2003