Australian state authorities have approved a massive wind farm project on an island off the coast of northwest Tasmania but under one condition: The 122 wind turbines must power down for five months out of the year to make sure they don't disrupt the migration patterns of the critically endangered orange-bellied parrot. 

Andrew Paul, chair of Tasmania's Environmental Protection Authority (EPA), said the decision was based on the fact that the agency had "limited knowledge about the importance of Robbins Island in the annual northern and southern migrations…" 

The announcement of such a long shutdown period caught the company behind the 900-megawatt wind farm by surprise. David Pollington, chief operations officer for ACEN Australia, told a local news source that it was "completely unexpected." 

Like many wind projects in the United States, the Robbins Island Renewable Energy Park has proven contentious among locals, and has entailed an intensive regulatory approval process. 

“Various environmental issues were considered by the Board in its assessment, particularly management of threatened fauna species, including avian fauna and roadkill impacts to terrestrial fauna," Paul said. 

The orange-bellied parrot is among the last migratory parrot species in the world, and is currently at risk of going extinct in the next 3-5 years, according to Zoos Victoria, an Australian zoo-based conservation organization.

Threats to the species include a recent outbreak of Beak and Feather disease, an increase in natural predators, and habitat loss.