Integrated Listening and Reading — 6

Marsupials

Marsupials are a group of mammals that are born alive after a very short gestation period. Since a marsupial appears quite early in its life cycle, it must complete its development while nursing. In order to survive, the young underdeveloped marsupial, immediately after its birth, must crawl over its mother's body to a fold of skin known as a pouch. During further development, which can last weeks or months, depending on the species, a marsupial nurses and grows inside the pouch. Most marsupials do not form family groups. It is the female marsupial that cares for the offspring. The young marsupial may stay with the mother for more than a year, climbing in and out of the pouch to nurse or sleep.

Although marsupials once ranged throughout North and South America, as well as in Antarctica, only a few species now live outside of New Zealand and Australia where more than 250 species are still found. There is quite a diversity of marsupials within these species, and they have adapted to a number of different habitats; however, some characteristics are universal among them. The senses of hearing and smell are very important to marsupials because they are nocturnal creatures that depend on their ears and nose to locate their food at night. Some marsupials prefer plants, although others eat insects or meat. Like other mammals, marsupials are covered with hair. Unlike other mammals, however, marsupials have additional bones to support the pouch, which is their unique adaptation.