Their thunderous roars are difficult to reconcile with the familiar perception of them as cuddly creatures. But it turns out their world is in fact far from cute and cuddly. Rather it is filled with social pressure, conflict, disease, overcrowding and the external stresses of living in the middle of what amounts to an alien world. Predominantly slow-moving, energy-conserving koalas are not exactly well-equipped to handle speeding traffic and packs of dogs, or the consequences of encroaching urbanization. For a real change of pace, Nature enters the world of urban koalas trying to adapt to life in the fast lane.
Cracking the Koala Code, Nature, Wednesday, August 28 at 7pm, explores the day-to-day dramas of a number of urban koalas, seen through the eyes of the scientists studying their every move and vocalization. Fascinating social dynamics include territorial displays, vicious fights, and the surprising mating strategies of traveling male koalas, rogues who truly play the field. New science even “cracks the koala communication code,” providing insights into their basic language and social structure.
“People love koalas, yet there is a great deal about them they would find surprising,” said Fred Kaufman, series executive producer and recently named recipient of International Wildlife Film Festival’s Lifetime Achievement Award. “Koalas may seem docile and sweet, but they are really quite active and can be very aggressive and loud. Viewers will get a whole new perspective after watching this film.”
Meet Mary, a typical suburban koala mom. While human life zooms around her, she remains still for hours on end, sleeping or resting 80 percent of each day. Like all koala mothers, her priority is her young joey as he grows and learns the ins and outs of his new world. She will protect her six-month-old, Bruce, until he is weaned. To keep up her strength, she snacks on gum leaves, a toxic diet lethal to most other mammals. But to process the nutrients in the leaves, she must chew the leaves for long periods of time before digesting them for more than 100 hours.
Buster, the alpha male in the territory, claims the exclusive right to mate with Mary and all the other females in his group. He is challenged by Jack, a young traveling male, who comes looking for his chance with Mary. But Buster, bellowing loudly and using his sheer brute force to intimidate Jack, asserts his dominance and sends him on his way.
Biologists Cathryn Dexter and David Black have been studying koalas in the Brisbane suburb of Petrie in an effort to understand the social interactions within an urban koala colony. They have been tracking the movements of more than 70 koalas, monitoring their health, providing medical assistance when necessary, and compiling data they hope will be useful in creating safe passageways through high traffic areas for the animals.
Elsewhere in Queensland, biologists Bill Ellis and Sean Fitzgibbon are engaged in research sponsored by the San Diego Zoo to learn more about the koala social system, mating habits and communication. Using 3G solar-powered mobile phones to record female koala vocalizations, and using those recordings in the field to evoke male koala responses, they have managed to decipher some of the koalas’ communications. Their studies suggest that female koalas may be able to tell which males are bigger, and therefore more attractive, by their bellows alone. Through DNA analysis, the team also made a most surprising discovery – that traveling males sire about 40 percent of the offspring in koala groups, despite the best efforts of the group’s resident dominant male.
Near the end of the mating season, Jack returns to Buster’s territory to try his luck again. He has grown stronger and more confident and this time the fight between Jack and Buster has a different ending. This time it is Buster who is forced out, leaving Jack to take over his territory and his females. Meanwhile, Bruce, now thirteen months old, has reached the first stage of adulthood and will also leave the colony to set out on his own within the patchwork of forest territories in the surrounding suburbs that have become his home.