The Unique , Sleeping Habits , of Whales.<br />'Newsweek' reports that whales, <br />being aquatic mammals, require both <br />sleep and oxygen in order to survive. .<br />It's an interesting dilemma <br />for wholly aquatic air-breathers, Naomi Rose, Marine Mammal Scientist at the Animal <br />Welfare Institute, via 'Newsweek'.<br />To deal with living in the water full-time, <br />while having to breathe air at the surface, <br />they have evolved into voluntary breathers, <br />as a way to prevent accidentally inhaling <br />water at inopportune moments, Naomi Rose, Marine Mammal Scientist at the Animal <br />Welfare Institute, via 'Newsweek'.<br />Depending on the species, of which <br />there are around 90 different kinds, whales <br />can hold their breath for about an hour. .<br />However, 'Newsweek' reports, whales <br />usually surface for air every 15 minutes. .<br />This means that whales <br />sleep in a very different <br />way than other mammals. .<br />Naomi Rose, Marine Mammal Scientist at the Animal <br />Welfare Institute, explains that cetaceans, which <br />include whales, dolphins and porpoises, would <br />drown if they became fully unconscious. .<br />They continue to swim, slowly and regularly—in tight synchronous formation for social cetaceans—occasionally floating still for a few seconds, up to a couple of minutes, perhaps, often very near the surface, Naomi Rose, Marine Mammal Scientist at the Animal <br />Welfare Institute, via 'Newsweek'.<br />Sperm whales hang in groups near the <br />surface and enter relatively deeper sleep. .<br />Humpback whales have been observed resting <br />on the surface for up to 30 minutes. .<br />Socially-complex killer whales <br />sleep in tight-knit groups with <br />other members of their pod.
