Oral Presentation- Symposium 12th International Mammalogical Congress

Change in territoriality of Tasmanian devils following a strong population decrease caused by a transmissible cancer. (#75)

Sebastien Comte 1 , Rodrigo Hamede 1 , Scott Carver 1 , Menna Jones 1
  1. School of Biological Sciences, University of Tasmania, Hobart, Tasmania, Australia

Tasmanian devils (Sarcophilus harrisii), which are endemic to the island of Tasmania, have declined by 85% in the 20 years since the emergence of an aggressive transmissible cancer, devil facial tumour disease (DFTD). The population of devils on the Freycinet peninsula has been monitored by live trapping since 1999, two years prior to the first case of DFTD in this area (2001). This particular year, VHF collars were deployed on adult animals before and after the mating season (February and May respectively). Fifteen years later, DFTD has reduced the devil population by nearly 90%, yet instead of driving its host to extinction, the tumour has disappeared from part of the area, now for three years. GPS collars were deployed in 2015 and 2016 to evaluate how the spatial organisation of the population changed in response to the epidemic. The first results suggest that home range sizes did not significantly change with the decrease in population, and males still use larger areas than females. Before the disease outbreak, devils showed minimal territoriality resulting in many individuals sharing the same area. Following the DFTD epidemic and population decline, there is stronger spatial avoidance, especially between individuals of the same sex. Linking this change in spatial organisation with live trapping records and genetic data will help us to understand how and why DFTD disappeared from the Freycinet peninsula. This unprecedented knowledge on the transmission of DFTD within wild populations of Tasmanian devils will hopefully help conservation strategies to save this emblematic mammal.