Keystone Predator Report

Ever since the devil facial tumor disease (DFTD) emerged in the mid-1990’s, the Tasmanian devils’ population has been on a rapid decline. As these devils are a keystone species of their ecosystem, their decline has allowed non-native predators such as cats and black rats to flourish and decrease the number of native prey. This effect is an example of the top-down keystone predator hypothesis. Due to the downfall of the devils, Australia’s once most intact faunal communities has diverted into an invasive state with severe biodiversity loss. Over 84% of the Tasmanian devils’ range has been affected by DFTD with 90% decrease of individuals of a population in early-diseased areas. Hollings et al. (2016) say that there are still a few devils that persist in these regions in small quantities,
In their research, Hollings et al. (2016) split the diseased regions into three: Northeast Tasmania was designated as the early-diseased region since the DFTD outbreak occurred between 1996 and 1999, the central section of the island was determined as the midterm-disease region where the outbreak occurred between 2003 and 2007, and lastly the Northwest part of Tasmania chosen as the disease-free region where there are still high densities of devil population. Hollings et al. (2016) wanted to see how the composition and abundance of mammal communities vary with time since the outbreak of the DFTD as well as the decline of apex predators like the Tasmanian devils. To test this, they formulated four basic questions: (1) Is abundance or activity of alien invasive mammal species