KOALA Phascolarctos cinereus MAMMAL Order Marsupialia Description 2-3 ft long; 10-30 lbs, males larger. Pear-shaped body, no tail, broad face with small eyes, large black nose covered with dry hairs and large, rounded ears. Scent glands on chest (males); pouch opens to the rear (females). Each hand with 2 opposable thumbs; each foot with one opposable toe and the first two digits joined together. Fur short to shaggy, color gray to brown, depending upon geographic variation. Range eastern Australia from northern Queensland to southwestern Victoria; introduced into western Australia and nearby islands. Status Although hunting koalas is currently outlawed, deforestation is removing habitat and food sources for this animal. Except for breeding programs, exportation of koalas is also outlawed. Research is currently underway concerning the diseases that plague koalas in the wild. If breeding and research programs continue, and hunting/export laws continue to be enforced, the koala should stay clear of the endangered species list. Many reserves exist, but they are separated by large areas, so breeding programs must include managing these reserves. Lincoln Park ZooKeeper in Australia with Australian Koala Foundation. Photo © James P. Rowan

Ecology Habitat eucalyptus (gum tree) forests and woodlands.   Niche strictly arboreal, living in and feeding on the leaves of eucalyptus trees. Caecum of gut is greatly enlarged (about 6 ft. long) and houses a large bacterial colony that aids in leaf digestion. Usually comes to ground only to change trees. Preyed upon at those times by foxes and dingos. Young hunted by large birds of prey.   Behavior Clumsy but strong swimmers. Lives in loose-knit groups if enough suitable trees are present, but only one animal per tree. Males express territoriality during breeding season, bellowing and grasping the base of a tree while rubbing the chest against it, thus scent marking with chest gland. Females bellow as well during this time but are not territorial. NOTE: The koala's closest living relative is the wombat, which is a stationary burrower rather than a nomadic arboreal like the koala. One clue to this relationship is the common design of the pouch, which opens to the rear in both animals. Life History Mating occurs Nov-Feb in the south, Sep-Jan further north. Gestation about 35 days; single young weigh about 1/5 oz and are about 3/4 in long. Newborn crawls from cloaca to pouch and attaches to a nipple to complete its development. Leaves pouch .first at about 5.5 months, permanently at about 8 months. Young joey then clings to mother's back or stomach, sticking head into pouch to feed. During weaning, joey eats partially-digested eucalyptus that emerges from mother's cloaca, thus receiving bacteria needed for digestion as well as food. Life span 12+ yrs (wild) 16+ yrs (captivity).   Special Adaptations Extra thick fur, especially on the neck and shoulders, helps protect animal from even the worst weather (koalas do not build nests). Pear-shaped body provides stability while animal sits in trees. Opposable thumbs and toes allow for a tight grip when climbing. Long claws help to grip tree bark; double digits joined on toes have the two claws close together to form a comb-like structure for grooming. Rough pads on undersurface of hands and feet increase traction while animal is climbing. Large nose with sensitive hairs enables animal to detect differences in smell between different eucalyptus leaves, ensuring that its diet consists of only the best of the bunch. Cheek pouches allow animal to store food not yet chewed while moving to a safer or more protected location. Koala cools itself by licking its arms and stretching out as it rests in the trees (koalas have no sweat glands).