The black footed-ferret, which was once thought to be extinct, is the most endangered mammal in North America; the prairie dog is hunted by some cattle ranchers because the animals eat too much grass.
"This is the 30th anniversary of the rediscovery of the Black Footed Ferret. In 1981 is when they found the last population of Black Footed Ferrets in McKeesen, Wyoming and before that they thought the species was actually extinct," Dr. Rachel Santymire, Lincoln Park Zoo endocrinologist, said.
At that time there were just 18 of these ferrets left in the world and that's when the rescue plan began. There aren't any Black-footed ferrets at Lincoln Park Zoo -- they're too few.
"Black-footed ferrets eat prairie dogs... Not much else. It's pretty much just prairie dogs," Rachel Bergen, v.p. of zoo education, said. "No prairie dogs, no black footed ferrets."
It's one of those crazy cycles of nature. The ferrets need the prairie dogs for food. The prairie dogs eat the prairie grasses and the land itself is healthy because of the prairie dogs and their tunnel systems.
"They help maintain the grasslands by maintaining the grasses. Also by keeping the soil aerated," Santymire said.
Public land is being used now to protect the prairie dogs from hunting by farmers and the ferret is coming back.
"We started with 18 individuals and from those 18 individuals in thirty years we've produced 7700 black footed ferrets," Santymire said. "Currently we have about 1,000 that are living in the wild."
Lincoln Park Zoo is holding an event Thursday night -- Wine & Wildlife: Black-Footed Ferrets- Back from the Brink -- to raise money for Prairie Wildlife Research .