Macropods are marsupials native to Australia and Papua New Guinea. They have large strong hind legs and feet, and long muscular tails which they use for balance.
There are two distinct groups. Kangaroos, wallabies, pademelons and tree kangaroos make up one group, rat-kangaroos, bettongs and potoroos make up the other.
All female macropods have a front opening pouch and gives birth to a tiny underdeveloped foetus like joey weighing less than a gram. The joey makes the journey unaided to mother’s pouch, where it attaches to one of four teats. The teat swells inside the joey’s mouth to hold the joey in place and it remains attached to the teat being nourished by its mother’s milk as it grows till it is fully developed. The joey’s first emergence from the pouch is at about 6 months old (depending on species) at which time it will hop out of the pouch for the first time and hop straight back in. As it gains confidence and strength the time out of the pouch will increase till finally it is fully emerged, usually at around 8 months of age. It will continue to suckle from the mother’s teat till it is (again depending on species) approximately 12 months old.
Once the joey leaves the pouch for good, mum will give birth to another tiny joey. She will feed both joey’s producing two different strengths of milk, one suitable for her tiny under developed joey and one for her now at foot joey.
Female Macropods have the ability to delay birth of their baby until their previous Joey has left the pouch. This is called embryonic diapause.