BOISE, Idaho (AP) — Scientists say that if increasingly destructive wildfires in the Great Basin can't be stopped the sage grouse population will be cut in half over the next three decades.

The report released Thursday by the U.S. Geological Survey comes just ahead of a court-ordered Sept. 30 deadline faced by the U.S. Fish and Wildlife Service to decide whether sage grouse need protection under the Endangered Species Act.

The study projected wildfires and recovery rates of burned areas and predicted long-term sage grouse population declines in Nevada, Utah, Idaho, Oregon and California.

But the study also identified ways to avert those declines by classifying areas for their resilience to disturbance and resistance to invasive species such as cheatgrass, and then applying suitable strategies.