Males fight one another for the females, and then guard their partners to prevent female infidelity.Females can ovulate three times in as many weeks during the mating season, and 80% of two-year-old females are seen to be pregnant during the annual mating season.Because they were seen as a threat to livestock and animals that humans hunted for fur in Tasmania, devils were hunted and became endangered.
Programs are currently being undertaken by the Government of Tasmania to reduce the impact of the disease, including an initiative to build up a group of healthy devils in captivity, isolated from the disease.
While the thylacine was extant it preyed on the devil, which targeted young and unattended thylacine cubs in their dens.
Despite its rotund appearance, the devil is capable of surprising speed and endurance, and can climb trees and swim across rivers.
It is believed that ancient marsupials migrated from what is now South America to Australia tens of millions of years ago during the time of Gondwana, and that they evolved as Australia became more arid.
Females average four breeding seasons in their life and give birth to 20–30 live young after three weeks' gestation.