NEW YORK, March 19 (UPI) -- Saiga, an Asian antelope, isn't only an endangered species but is threatened by development in Mongolia that might cut off a key migration route.

NEW YORK, Feb. 14 (UPI) -- The U.S. Wildlife Conservation Society is trying to figure out why jack rabbits have vanished from Yellowstone National Park.

NEW YORK, Oct. 10 (UPI) -- U.S. researchers said moose in the Greater Yellowstone Ecosystem move instinctively toward humans to gain safety while giving birth.

NEW YORK, June 20 (UPI) -- A U.S. study suggests large prey, including moose, caribou and elk, only fear the predator species that they regularly encounter.

BOZEMAN, Mont., July 10 (UPI) -- A mammal that embarks on the longest remaining overland migration in the continental United States might vanish from the Yellowstone Park ecosystem.

NEW YORK, June 15 (UPI) -- The U.S. Wildlife Conservation Society has released the first-year results of a study on how natural gas development in the Rockies might affect wildlife.

BOULDER, Colo., Feb. 2 (UPI) -- A series by UPI examining the relationship of humans to the environment. This week: Could it really be the issues galvanizing the debate on wilderness in the United States remain virtually the same today as they were nearly 30 years ago? Well, yes.

BOULDER, Colo., April 22 (UPI) -- The continental United States once witnessed vast herd migrations as bison, elk, antelope and deer moved freely from winter grounds to summer grass, and though caribou herds still migrate hundreds of miles in Canada and Alaska, biologists warn these behav

CHEYENNE, Wyo., March 12 (UPI) -- U.S. animal migration in places like the Yellowstone National Park are being cut off by encroaching human habitation and energy plants and pipelines.