Tasmania supports a number of native Australian mammals whose mainland counterparts have severely declined or disappeared since European settlement such as the Eastern quoll (Dasyurus viverinus) and the Tasmanian bettong (Bettongia gaimardi). The top predator in Tasmania is the iconic Tasmanian devil (Sarcophilus harrisii) whose population has recently suffered a severe decline due to the arrival of devil facial tumour disease (DFTD). From the northeast DFTD has spread south-west covering more than half of the known distribution of the Tasmanian devil just ten years after it first appeared. There is evidence that the presence or absence of Tasmanian devils can affect the presence and absence of smaller predators such as the feral cat (Felis catus) and eastern quoll as well as the local prey species. The current and ongoing collapse of the Tasmanian devil population in the northeast of Tasmania and the unaffected populations in the northwest provides a unique opportunity to study ecosystem changes through the use of a non-invasive genetic technique using trace DNA. Applying this technique to mammalian predator scats collected over a six-year period, we were able to identify both predator and prey species and examine the change in frequency of devil scats across time and space. We then investigated changes in predator diets in response to changes in devil scat frequency and discuss the impact of DFTD across multiple trophic levels.