The red knot makes one of the longest migrations of any animal. To accomplish this feat, it relies on the eggs of the horseshoe crab. Without these eggs, the red knot is in danger.

Ecologists once thought ecosystems were largely influenced from the bottom up, but predators can also be the drivers of the system.

Population by population, species by species, amphibians are vanishing off the face of the Earth. Watch the full episode now.

Collected and protected by dedicated scientists, these animals represent the end of the line for their species. Watch the full episode now.

Up to 100 species disappear from the planet each day. In this web-exclusive video, scientists and conservationists discuss the importance of biodiversity.

Meet some of the people featured in The Loneliest Animals, who are working to prevent species extinction around the world.

Explore places around the world with high numbers of endangered species, and see some of the creatures affected.

In China, the last female rafetus turtle is about to be introduced to her new home, where the last male is waiting to meet her.

(Airs Sunday, March 7) Around the globe, unique and fascinating species face extinction. Follow the plight of these creatures and the dedicated conservationists who fight for them.

Wolves from the Druid pack chase down an elk.