Koalas are marsupials, a group of mammals characterized by a pouch. The answer to whether koalas have pouches like kangaroos is yes. This specialized abdominal pocket provides a safe, nurturing environment for their underdeveloped young.
The Koala’s Pouch
The koala’s pouch is a skin fold located on the mother’s abdomen. Unlike the kangaroo’s pouch, which opens forward, a koala’s pouch opens toward the rear of her body, facing downward when she is upright. This orientation is an adaptation to their arboreal lifestyle. The backward-facing opening helps prevent the joey from falling out as the mother climbs through eucalyptus trees.
A koala mother can actively control the pouch opening using a strong sphincter muscle. This muscle keeps the pouch tightly closed, securing the joey and protecting it from external elements while she navigates the tree canopy. Unlike kangaroos, koalas require this active closure. The koala’s pouch is also furless inside, providing a warm, clean environment for the developing joey.
Pouch Life for Koala Joeys
Koala joeys are born in an underdeveloped state after a gestation period of about 35 days. At birth, a joey is tiny, resembling a pink jellybean, measuring around 2 centimeters and weighing less than a gram. It is blind, hairless, and earless. The newborn joey instinctively crawls from the birth canal into the mother’s pouch, navigating through her fur.
Once inside the pouch, the joey immediately attaches itself to one of the mother’s two teats, securing it in place. The joey remains in the pouch, drinking milk and growing, for approximately six to seven months. During this time, it develops fur, its eyes open, and ears unfold. Around 5 to 6 months of age, the joey begins to poke its head out of the pouch, and by 7 months, it starts to emerge for longer periods, eventually riding on its mother’s back or abdomen.
More Than Just Koalas and Kangaroos
The presence of a pouch is a distinguishing characteristic of marsupials, a diverse group of mammals found primarily in Australasia and the Americas. The term “marsupial” is derived from “marsupium,” the Latin word for pouch. Marsupials give birth to live, undeveloped young that continue their growth and nourishment within this external pouch.
While koalas and kangaroos are well-known examples, many other marsupial species also possess pouches, often with variations tailored to their specific lifestyles. For instance, wombats, close relatives of koalas, have backward-opening pouches, which prevents dirt from entering while they dig burrows. Other marsupials like wallabies, possums, and Tasmanian devils also utilize pouches for their young’s development.