LARAMIE (AP) - Twenty conservation organizations submitted a petition to the U.S. Fish and Wildlife Service on Monday to list the greater sage grouse as threatened or endangered under the Endangered Species Act.

The species has suffered declines of 45 percent to 80 percent over the past 20 years due to habitat loss, the groups said.

"The sage grouse is clearly in trouble," said Erik Molvar, wildlife biologist for Laramie-based Biodiversity Conservation Alliance. "And yet the deterioration in land stewardship on federal public lands is driving this bird even faster towards extinction.

"In particular, the radical increase in oil and gas drilling, paired with the failure to provide common-sense protections for the most sensitive habitats, is driving the sage grouse out of its natural strongholds."

Experts think as many as 2 million sage grouse inhabited a broad area of the Western United States and Canada when explorers Lewis and Clark first noted the birds in 1805.

Today, their numbers are estimated at 140,000 to 250,000 over 11 states.

The U.S. Fish and Wildlife Service has received numerous petitions in recent years to protect sage grouse under federal laws but has declined to do so.

The conservation groups said they have submitted new information about threats to sage grouse since the last petition was filed in 2002.

Among the organizations filing the petition were American Lands Alliance, Center for Biological Diversity, Forest Guardians, The Fund for Animals, Gallatin Wildlife Association, Hells Canyon Preservation Council, The Northwest Coalition for Alternatives to Pesticides, Northwest Ecosystem Alliance, Oregon Natural Desert Association, Oregon Natural Resources Council, Predator Defense Institute and the Sierra Club.