Dolphins are highly intelligent and can be found all over the world in oceans, rivers and estuaries. As mammals, dolphins don"t have gills so they can"t breathe underwater. They must surface to inhale and exhale stale air, which they do through blowholes and not their mouths. How long they can hold their breath depends on the species; some can go for 3 to 7 minutes, while others can stay submerged for up to 20 minutes. Because they must always surface, half of dolphins" brains are always active, meaning they never completely fall asleep. Despite being able to exist in an array of environments and water temperatures, dolphins are threatened by a variety of human activities, such as hunting, pollution and fishing.
Dolphin pod near Réunion island
Today in History
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Mer de Glace, Chamonix, France
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Delicate Arch, Arches National Park, Utah, United States
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Staubbach Falls at Lauterbrunnen, Canton of Bern, Switzerland
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Bohemian waxwings
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Bengal tiger, India
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Milwaukee City Hall, Wisconsin, United States
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Huangshan Mountains, China
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Green sea turtle
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Pegadung Rock, Lampung, Sumatra, Indonesia
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Third Thai-Lao Friendship Bridge connecting Laos and Thailand
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Ad-Deir, Petra, Jordan
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Skåne County, Sweden
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Füzér Castle in the Zemplén Mountains, Hungary
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Tasmans Arch, Tasman National Park, Tasmania, Australia
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Belém Tower, Lisbon, Portugal
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African elephants, Tanzania
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Amazon rainforest, Brazil
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Natural arch carved in an iceberg, Antarctica
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Anshun Bridge, Chengdu, China
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Reine, Norway
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Nighttime view over the Gulf Coast
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Oxbow Bend on the Snake River, Wyoming, United States
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Bamburgh Castle, Northumberland, England
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The Pragser Wildsee in the Dolomites, Italy
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Oktoberfest, Munich, Germany
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Pumpkin field, Victoria, British Columbia, Canada
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Martimoaapa Mire Reserve, Finland
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Barracudas at Shark Reef, Ras Mohammed National Park, Sinai Peninsula, Egypt
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Annas hummingbird
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