What disease has caused major population declines in Tasmanian devils?

Devil facial tumour disease has caused major population declines in Tasmanian devils.

It is a transmissible cancer spread mainly when devils bite one another, especially around the face during feeding and social conflict. Tumours commonly develop around the mouth and face, interfering with eating and eventually causing death. Unlike ordinary cancers, the tumour cells themselves pass between animals and continue growing in new hosts.

The disease was first recorded in Tasmania in the 1990s and spread across much of the island. It caused severe declines in affected populations and became one of the most serious threats to the species. A second transmissible devil cancer, devil facial tumour 2, was identified later, showing that the risk is not limited to one tumour lineage.

Conservation programmes include monitoring, captive breeding, insurance populations and releasing disease-free devils. Researchers have also studied natural genetic resistance. The disease is not the same as chytridiomycosis, which is a fungal disease affecting amphibians.