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.
The story of the farmers who dreamed of prosperity and lived through ten years of drought, dust, disease and death.
John Wesley Powell's epic journey into the unknown Grand Canyon was filled with adventure as his team mapped the Colorado River for the first time.
The New Deal program CCC put three million young men to work in camps across America.
Her 1963 warnings about the effects of pesticides and herbicides sparked a revolution in environmental policy.
When an earthen dam broke without warning, a small city in Pennsylvania was swept away in a wall of water over 30 feet high.
This stunning film portrait of Yosemite National Park uses the 1851 diary of the first expedition of soldiers into the Native American territory.
Vivid memories of those trapped in the terrifying temblor of 1906 that killed thousands of Californians.
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.