Because marsupial babies do most of their development outside their mother's body and inside their pouch, they are extremely small at birth. The smaller wallabies weigh less than 0.5g at birth, while kangaroos, such as the red or the grey, weigh about one gram.
Gestation lasts around one month. The newborn animals clamber up the belly of the mother, over the lip of the front-opening pouch, and attach themselves to one of the teats inside. They stay there for between five and 12 months (depending on the species), and suckle from the same teat for two to six months after they leave the pouch.
They stay close to their mother until they are sexually mature - this may be at 18 months in larger species. In most species only one offspring is born at a time and twin births are rare. However, in the musky rat kangaroo, twins are normal. In almost all species the female may mate shortly after giving birth. A dormant embryo results, and does not develop further until the offspring of the previous mating leaves the pouch.
Gestation lasts around one month. The newborn animals clamber up the belly of the mother, over the lip of the front-opening pouch, and attach themselves to one of the teats inside. They stay there for between five and 12 months (depending on the species), and suckle from the same teat for two to six months after they leave the pouch.
They stay close to their mother until they are sexually mature - this may be at 18 months in larger species. In most species only one offspring is born at a time and twin births are rare. However, in the musky rat kangaroo, twins are normal. In almost all species the female may mate shortly after giving birth. A dormant embryo results, and does not develop further until the offspring of the previous mating leaves the pouch.
