Whales' methods of communication are complicated, and not yet well understood by scientists. Listen to examples of the vast differences in sounds that whales produce in these five recordings of whale vocalizations.
Recording 1: A humpback whale recorded March 22, 2003 at Isla Socorro, Revillagigedo Archipelago, Mexico. Credit: Danielle Cholewiak, PhD., Acoustic Specialist, Stellwagen Bank National Marine Sanctuary. NOAA/NOS
Recording 2: A humpback whale. Credit: Sofie Ban Parijs, Northeast Fisheries Science Center, NOAA Fisheries Service.
Recording 3: A sperm whale echolocating. Courtesy of the Scripps Whale Scoustic Laboratory.
Recording 4: A right whale. Courtesy of the Scripps Whale Scoustic Laboratory.
Recording 5: Another right whale. Courtesy of the Scripps Whale Scoustic Laboratory.
Before radar had been invented a devastating hurricane hit America, surprising residents of the East Coast and killing more than 600 people.
The life of the legendary photographer, known best for his black and white images of the wilderness of the American West.
High on a granite cliff in South Dakota's Black Hills tower the huge carved faces of four American presidents: George Washington, Thomas Jefferson, Abraham Lincoln, and Theodore Roosevelt.
The story of the farmers who dreamed of prosperity and lived through ten years of drought, dust, disease and death.
The American effort to relieve starvation in Soviet Russia in 1921 during the worst natural disaster in Europe in 500 years.
A daunting story of shipwreck, starvation, mutiny and cannibalism amongst a group left abandoned in the high Arctic.
This stunning film portrait of Yosemite National Park uses the 1851 diary of the first expedition of soldiers into the Native American territory.
Native Alaskans, oil company representatives, environmentalists, politicians, and others tell the story of the 800-mile pipeline.