Characteristically Koala From nose to toes to rounded rump, see for yourself how koalas are well-suited for life in the trees. FUR: A koala’s fuzzy appearance belies the reality that its fur is quite coarse. Described as feeling like sheep’s wool, the koala’s dense coat protects it from both extremely hot and cold conditions. It’s also water resistant, so a rainy day is no problem. The color of the fur can vary, depending on which part of Australia the individual is from; koalas in the south usually have thicker, darker fur than those in the north.
NOSE: Big nose, big role! The sense of smell is one of a koala’s best senses. A foraging koala spends a great deal of time sniffing out just the right bit of eucalyptus. This helps the animal get the most nutritious leaves and avoid non-edible eucalyptus. Although able to process some of the toxins in eucalyptus leaves, there are some eucalyptus species that are even poisonous to koalas. A keen sense of smell plays a vital role in koala communication as well. Males leave scent marks on trees to both welcome females and warn off intruding fellows.
MALE KOALA SCENT GLAND: This small, bare patch of skin is where the male’s scent gland is located. When the male rubs this spot against a tree or branch, the sticky brown secretion spreads his special smell. Varying amounts of 40 chemicals give each male koala his own signature scent for attracting females and warding off other males.
MOUTH: Koalas make several different vocalizations, from snores to screams to bellows. (Tap on video link below to hear a bellow.) Both sexes bellow, but males seem to do it more often. San Diego Zoo Global researchers are trying to understand why they make this sound— is it to tell other males to stay away or to invite females to visit?
RUMP: Koalas are sedentary animals that sleep for long periods as they digest their food. To stay out of the reach of predators like dingoes, they curl up in the crook of a tree. A rounded rear end, curved spine, and barely-there tail allow koalas to fit into a snug spot for a snooze. Extra-thick fur on the rump provides padding against the hard branches.
ARMS: Strong arm and shoulder muscles help a koala climb 150 feet to the top of a tree and enable it to leap between branches. Being on the ground all the time would be a disadvantage, because predators could easily catch a koala.
HANDS: Koala hands and FEET: Count the digits on a
HINDGUT: Eucalyptus
koala’s foot, and you’ll tally four: the first two toes are fused together. This twoin-one tool grips branches and does double duty as a grooming apparatus. The two claws close together work like a comb when raked through the fur. These tree dwellers also have one clawless toe that acts like a thumb for gripping branches.
leaves may not contain as much nutrition as other plant material, but they’re plentiful in the koalas’ native range—and no one else really eats them. That’s because eucalyptus leaves contain toxic compounds that are poisonous to most other animals. Koalas, however, have a special bacteria in their digestive tract that breaks down the toxins while nutrients are absorbed from the leaves.
FEMALE KOALA POUCH: Like all marsupials, female koalas have a pouch in which they carry their baby, called a joey. Many marsupials, like kangaroos, have a pouch that opens upward, toward their head. But koala moms have a pouch that opens toward their hind legs. After the tiny joey is born, it uses strong forelimbs and hands to crawl from the birth canal into its mother’s pouch. Inside the pouch are two nipples. The joey latches onto one and stays snug and safe, drinking milk and growing, for about six months.
feet curl around tree branches effectively. Each hand has two—count ‘em, two— opposable thumbs that give koalas an extra bit of grasping ability. Rough, ridged pads on the hands and feet aid their grip and provide traction. And, of course, those long, sharp claws for clutching tree bark help their clinging capability (although they can hurt human skin).