of northern Australia and New Guinea coexisted with the Thylacine, but had developed strong defenses against predators; the emu on the other hand was more vulnerable to the Thylacine's adaptions including endurance hunting and bipedal hop. Dingoes, feral dogs, and red foxes have all been noted to hunt the emu on the mainland and killings of emus by dogs were noted in Tasmania. European settlers believed the thylacine to prey upon farmers' sheep and poultry. Throughout the 20th century, the thylacine was often characterised as primarily a blood drinker; according to Robert Paddle, the story's popularity seems to have originated from a single second-hand account heard by Geoffrey Smith (1881–1916) in a shepherd's hut. There is some controversy over the preferred prey size of the thylacine. A 2011 study by the University of New South Wales using advanced computer modelling indicated that the thylacine had surprisingly feeble jaws. Animals usually take prey close to their own body size, but an adult thylacine of around was found to be incapable of handling prey much larger than . Thus, some researchers believe thylacines only ate small animals such as bandicoots and possums, putting them into direct competition with the Tasmanian devil and the tiger quoll. Another study in 2020 produced similar results, after estimating the average thylacine weight as about rather than , suggesting that the animal did indeed hunt much smaller prey. However, an earlier study showed that the thylacine had a bite force quotient of 166, similar to that of most quolls; in modern mammalian predators, such a high bite force is almost always associated with predators which routinely take prey as large, or larger than, themselves. If the thylacine was indeed specialised for small prey, this specialisation likely made it susceptible to small disturbances to the ecosystem. Analysis of the skeletal frame and observations of the thylacine in captivity suggest the species were pursuit predators, singling out a prey item and pursuing them until the prey was exhausted. However, trappers reported it as an ambush predator. The animal may have hunted in small family groups, with the main group herding prey in the general direction of an individual waiting in ambush. Although the living grey wolf is widely seen as the thylacine's counterpart, the thylacine may have been more of an ambush predator as opposed to a pursuit predator. In fact, the predatory behaviour of the thylacine was probably