A Pika (Ochotona princeps) pauses while gathering grasses for hay grainery, Jasper National Park, Alberta, Canada
The pika is a small mammal related to the rabbit with rounded ears and no discernable tail. The American pika, according to the World Wildlife Fund, is particularly vulnerable to global warming because it lives in cool, relatively moist habitats found at high elevations — environments that could shrink dramatically as the Earth heats up.