字幕表 動画を再生する 英語字幕をプリント You're watching FreeSchool! Let's learn about koalas! Although you may have heard them called koala 'bears,' koalas are not bears at all! Like bears, koalas are mammals, which means they are warm-blooded, have fur, and feed their babies milk. Unlike bears, koalas are a special kind of mammal called 'marsupials.' Marsupials have pouches to carry their babies in for a few months after they are born. Kangaroos are probably the most famous marsupials, but koalas have pouches too! Baby koalas are called joeys. When they are born, they are only about the size of a jellybean. They have no fur and their eyes and ears are closed. Koala joeys will stay in their mothers' pouches for about six months. Once a baby koala comes out of the pouch, it will hang onto its mother's back or stomach and stay with her for another six months. Full grown koalas reach lengths of 24 to 33 inches or 60 to 85 cm, and weights of up to 33 lbs or 15 kg, although the females are usually much smaller. Koalas are native to eastern Australia, where the eucalyptus forests they call their home grow. They are herbivores and eat almost exclusively eucalyptus leaves. Although there are about 600 types of eucalyptus trees in Australia, koalas will only eat about 120 of them, and an individual koala will only eat leaves from about 4 to 6 types. Eucalyptus trees are both food and a home for koalas. Koalas have short, curved claws, ideal for climbing trees, and two thumbs on their front paws that help them to grip small branches. They rarely even come to the ground to drink: the name 'koala' is from an Aboriginal word meaning 'no drink,' because koalas get most of their water from the leaves they eat. Koalas spend almost all of their time in the treetops, eating, or more likely, sleeping. Koalas usually sleep between 18 and 22 hours a day - it takes a lot of energy to digest eucalyptus leaves. Eucalyptus leaves are poisonous to most animals, but koalas have an extra-long digestive system that allows them to break down the leaves without being hurt by the poison. Although koalas are not currently endangered, they are in trouble. Once they were hunted in large numbers for their soft fur. Although they are protected now, they need plenty of eucalyptus trees - about 100 trees per koala - to have enough food to eat. As the forests they live in are cut down by humans, koalas have fewer and fewer places to live. If we want to make sure that koalas stay healthy and happy, we need to protect their habitats so they have enough trees to call home. I hope you enjoyed learning about koalas today. Goodbye till next time!