Koalas and Kangaroos: Managing Australia’s Charismatic Icons on the World’s Stage

The management of overabundant native mammals is a contentious issue. In Australia, this is exemplified by the management of kangaroos and koalas. The iconic status of these species, nationally and internationally, greatly influences the perception of acceptable wildlife management practices. Lethal control techniques now face widespread opposition. This has resulted in research and development of alternative management strategies, with emphasis on potential fertility control agents. Australian Research Council Funding in 2005 supported the formation of a new initiative: The Koala and Kangaroo Contraception Program. Over the last 7 years, our research group has been testing the effects of a long-acting contraceptive implant (Suprelorin®, Peptech Animal Health), containing the gonadotropin-releasing hormone (GnRH) agonist deslorelin, on kangaroos and koalas. Within the last year, we have commenced large-scale field trials on two species: koalas on Kangaroo Island, South Australia; and tammar wallabies on the Abrolhos Islands, Western Australia. These field trials aim to evaluate the efficacy of using long-acting contraception to control marsupial populations and will measure the effects of contraception at the individual, population, and environmental level. This is paralleled by development of a remote delivery system that will greatly enhance the efficacy of this form of population management.