Biologists install digital cameras and microphones around wild habitats to observe where endangered animals migrate. By mapping wildlife movements conservationists can advise governments how to build infrastructure that protects biodiversity.
Ancient footprints in White Sands National Park reveal evidence of Ice Age humans that walked the land earlier than archaeologists thought.
Republican candidates hoping to represent Arizona's sixth congressional district debate the issues.
Journey to South America to explore the magnificent flora and fauna of Colombia, from the Pacific coast to the the Andes.