AniVen

"Joey" - Eastern Grey - Macropus giganteus

At about one month, the tiny embryonic kangaroo emerges from its mother's body and slowly climbs up her abdomen and into her pouch. Once inside the pouch, the newborn latches onto a teat(nipple) which swells inside its mouth. Newborn marsupials do not have the ability to suck. Muscular action from the teat squirts milk into the baby's mouth. Newborns are about the size of a Lima bean. A baby kangaroo spends 7-8 months living and growing inside its mother's pouch. The baby then becomes active outside the pouch, returning only to feed.

When that happens, another baby joey can be born. Then two types of milk can be produced, one for the active joey, and one for the still developing joey inside the pouch. Kangaroos also have a reproductive adaptation called "delayed implantation." The fertilized egg will cease development and wait. Depending on the growth of the joey in the pouch or the weather that season, the fertilized egg will begin development when the mother kangaroo is ready. Eastern grey kangaroos generally give birth to one infant at a time but twins have been known to occur.