  The Devil Facial Tumour Disease (DFTD), a unique case of a transmissible
cancer, had a devastating effect on its host, the Tasmanian Devil. Current
estimates of its density are at roughly 20% of the pre-disease state, and
single-population epidemiological models have predicted the likely extinction
of the host. Here we take advantage of extensive surveys across Tasmania
providing data on the spatial and temporal spread of DFTD, and investigate the
dynamics of this host-pathogen system using a spatial metapopulation model. We
first confirm a most likely origin of DFTD in the north-east corner of the
island, and then use the inferred dynamics to predict the fate of the species.
We find that our medium-term predictions match additional data not used for
fitting, and that on the long-term, Tasmanian Devils are predicted to coexist
with the tumour. The key process allowing persistence is the repeated
reinvasion of extinct patches from neighbouring areas where the disease has
flared up and died out, resulting in a dynamic equilibrium with different
levels of spatial heterogeneity. However, this dynamic equilibrium is predicted
to keep this apex predator at about 9 % of its original density, with possible
dramatic effects on the Tasmanian ecosystem.
