"An intrepid bird called the red knot migrates from the southern tip of South America to the Arctic and back every year. But changes in climate along its route are putting this ultramarathoner at risk.

The federal government has proposed to list the red knot as threatened on the endangered species list, because of the risk of extinction the bird faces over its 9,300-mile journey, largely because of climate change.

"You know, this bird is facing any conceivable difficulty from Terra del Fuego [Argentina] all the way to the Arctic," says Kevin Kala, a biologist who manages the shorebird project for the Delaware Division of Fish and Wildlife. Kalasz has studied red knots for more than a decade."

Elizabeth Shogren reports for NPR July 28, 2014. [2]