字幕列表 影片播放 列印英文字幕 Penguins are aquatic flightless birds that are highly adapted to life in water. Their distinct appearance is called counter-shading which is a form of camouflage which helps them keep safe in water. In general, penguins love to eat krill, fish and squid however Penguins close to the equator eat more fish than Penguins close to Antarctica. Penguins can be found in every continent in the Southern Hemisphere from up close to equator right down to Antarctica. Penguins can spend up to 75% of their time in the water and they do all their hunting in the water because their prey can be found within 60 feet of the surface so they have no need to swim in deep water. Penguins catch their prey with their beaks and swallow them whole as they swim. Depending on the species, Penguins can live between 15 to 20 years. Penguins tend to vary in size from the Blue Penguin which is the smallest Penguin species that measures up to 16 inches tall to the largest Penguin which is the Emperor Penguin which measures up to 3.7 feet tall and weighs in between 60 - 90 pounds. Although they cant fly through the air with their flippers, many Penguins take to the air when they leap from the water onto the ice. Just before they take flight, they release air bubbles from their feathers which cuts the drag on their bodies and that allows them to double or triple their swimming speed quickly and launch into the air. Most species of Penguins swim underwater at around 4-7 mph, however the fastest Penguin which is the Gentou, can reach top speeds of 22 mph. Penguins don't have teeth, however they have backward facing fleshy spines that line the inside of their mouths which help them guide their fishy meals down their throats. Penguins are carnivores and feed on fish, squid, crabs, krill and other sea foods they can catch whilst they are swimming. During the summer they eat much more heavily than they do during the winter.During the winter they will just eat a third of what they will eat during the summer. Because they spend a lot of their time underwater, they take in a lot of salt water, however they have a special gland which is a super orbital gland that is located just above their eye that filters salt from their blood stream and is then excreted through the bill or by sneezing. Each year, Penguins experience a catastrophic moult where they lose the majority of their feathers. They can't swim and fish during this time, so they fatten themselves up beforehand to survive the two to three weeks it takes to replace them. All but two Penguins species breed in large colonies for protection. These colonies range from around 200 to hundreds of thousands of birds. Penguins distinct appearance helps them keep camouflaged whilst swimming. From above their black backs blend into the dark ocean water and from below their white bellies match the surface of the bright sunlight. This helps them to avoid predators such as leopard seals and hunt for fish unseen.