A topic of perpetual fascination, the kangaroos of Australia have been the focus of myriad books and documentaries. Kangaroos in Outback Australia focuses on Yathong Nature Reserve, where three species of kangaroo—red, eastern grey, and western grey—overlap and create a unique opportunity for ecological study.

Dale and Yvette McCullough spent fifteen months in Yathong examining the comparative ecology and behavior of the different species. The McCulloughs used systematic counts, radio telemetry, direct observations, and other techniques to characterize and compare the different species' population sizes, home ranges and movements, activity patterns, habitat selection, feeding behavior, and social organization.

The researchers' previous work on the kangaroos' closest ecological counterparts in North America, the white-tailed and the mule deer, serves as a subject for comparison and enlarges the overall scope of the work.