A Tasmanian devil sanctuary established on Maria Island is taking a toll on the island's bird population.
Tasmania's Environment Department is being forced to protect nests to safeguard vulnerable birds on the east coast island.
The ambitious program to safeguard the iconic marsupial from a deadly facial tumour was started in 2012.
Twenty-eight devils were released on the island, which is cut off from the diseased devil population on mainland Tasmania.
The population has grown to more than 90, raising questions about the effect the apex predator is having on the island's other species.
The devils have been attacking ground-nesting birds and there is anecdotal evidence that no chicks have been successfully reared this breeding season.
"I'm not happy to see them here, I think it's most unfortunate," Maria Island ferry owner John Cole-Cook said.
"Why should we threaten the 120 species of birds that use this island as a sanctuary of the predators?"
The translocation of the devils to isolate them from the contagious facial cancer has been hailed a huge success, but the department is now assessing its next step.