Bradley, Bixby, De-Vos, and Usmar arrived at the zoo last month and were placed into a mandatory 30-day quarantine. They came from the Taronga Western Plains Zoo in Australia.
Usmar is female, the rest are males.
Tasmanian devils, native to the island state of Tasmania, are nocturnal hunters that live in forest, woodland and agricultural areas and use their keen senses of smell and hearing to find prey or carrion. They can give off a fierce snarl and high-pitched scream, which can be heard at feeding time, to establish dominance.
They face extinction in the wild due to devil facial tumor disease, a rare, contagious cancer found only in devils. DFTD is transmitted from one animal to another through biting, a common behavior among devils when mating and feeding.
The disease kills all infected devils within six to 12 months, as there is no known cure or vaccine. The four Tasmanian devils at the San Diego Zoo are free of the disease.
The zoo is now part of the Save the Tasmanian Devil Program, a government initiative established 10 years ago to fight the condition.
The zoo plans a ceremony before the park opens to the public, with attendance by dignitaries from Australia and Tasmania.