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
More Desktop Wallpapers:
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Black-and-white ruffed lemur
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Vieste, Apulia, Italy
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Constitución railway station, Buenos Aires, Argentina
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Edinburgh Castle, Scotland, United Kingdom
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Indigo bunting
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Bengal tiger, India
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Kokino, North Macedonia
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Kinder Scout, Peak District National Park, UK
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Inside the Nobel Peace Centre, Oslo, Norway
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Zahara de la Sierra, Andalusia, Spain
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Banff, Alberta, Canada
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A group of Southern gemsbok in the savannah, Botswana, USA
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Great Smoky Mountains National Park, Tennessee, USA
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Whale shark
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Lakes of Covadonga, Asturias, Spain
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Schönbrunn Palace Park, Vienna, Austria
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View from the cupola of the International Space Station
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Dunes at White Sands National Park, New Mexico
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Medieval towers in Mestia, Upper Svaneti, Georgia
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Mother manatee and calf
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Badlands National Park, South Dakota, USA
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Glenariff Forest Park, County Antrim, Ireland
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Retiro Park, Madrid, Spain
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Tree frog on leaf
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Wadden Sea coast, Friesland, Netherlands
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Polar bear mother and cubs
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Lake Minnewanka, Alberta, Canada
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Humpback whale mother and calf
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Coco Beach, Goa, India
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Blue walls of Chefchaouen, Morocco
Bing Wallpaper Gallery

