Four more environmental groups are appealing a federal court order that gray wolves be removed from Yellowstone National Park and central Idaho.

Predator Project, the National Audubon Society, Sinapu and the Grey Wolf Committee on Wednesday filed an appeal of U.S. District Judge William Downes' ruling. He concluded in December that the U.S. Fish and Wildlife Service's wolf recovery program is illegal.The judge's order was stayed pending appeals, which have been filed by other environmental groups.

"We are fighting for the protection of all the wolves in the northern Rockies - both reintroduced and naturally occurring," said David Gaillard, a Predator Project spokesman. "We have repeatedly opposed the Farm Bureau's attempts to eliminate the transplanted wolves, and we will continue that battle until we overturn their victory."

Downes said the program did not provide protection required by law for wolves that may already be in the area or that may move south into the region from Montana.

Downes' ruling came in response to lawsuits filed not only by the Farm Bureau but by the Audubon Society and Jim and Cat Urbigkit, who have argued for years that a native wolf population already exists in the area.

But Gaillard blamed the judge's ruling on the Farm Bureau alone.