sierraclub.org - sierra magazine - sept/oct 2011 - endangered-species - on the brink: animals fighting for survival
Photography by Joel Sartore | Captions by Della Watson

Prairie dog eradication efforts in the early 1900s nearly wiped out the black-footed ferret, which depends on prairie dogs for food and shelter. North America's only native ferret was thought to be extinct until a group was discovered living on a ranch in Meeteetse, Wyoming. Only 18 survived an outbreak of disease at the ferret's last wild bastion. Today, thanks to captive breeding and reintroduction programs, the black-footed ferret population has reached about 800. (Photographed at the Cheyenne Mountain Zoo, Colorado Sprints, Colorado)
Get the Sierra Club Insider
Get the Sierra Club
Insider, our email newsletter. News, green lifestyle tips, and ways to take action: right to your inbox, twice a month.