Republicans in Congress on Tuesday called for an overhaul to the Endangered Species Act to curtail environmentalists' lawsuits and give more power to states, but experts say broad changes to one of the nation's cornerstone environmental laws are unlikely given the pervasive partisan divide in Washington, D.C.

A group of 13 GOP lawmakers representing states across the U.S. released a report proposing "targeted reforms" for the 40-year-old federal law, which protects imperiled plants and animals.

Proponents credit the law with staving off extinction for hundreds of species _ from the bald eagle and American alligator to the gray whale. But critics contend the law has been abused by environmental groups seeking to restrict development in the name of species protection.

Led by Rep. Cynthia Lummis of Wyoming and Rep. Doc Hastings of Washington state, who chairs the House Natural Resources Committee, the Republicans want to amend the law to limit litigation from wildlife advocates that has resulted in protections for some species. And they want to give states more authority over imperiled species that fall within their borders.

Also among the recommendations are increased scientific transparency, more accurate economic impact studies and safeguards for private landowners.

The Republicans said only 2 percent of protected species have been recovered despite billions of dollars in federal and state spending.

"The biggest problem is that the Endangered Species Act is not recovering species," said Hastings. "The way the act was written, there is more of an effort to list (species as endangered or threatened) than to delist."

The political hurdles for an overhaul are considerable. The Endangered Species Act enjoys fervent support among many environmentalists, whose Democratic allies on Capitol Hill have thwarted past proposals for change.

Federal wildlife officials said they had not yet seen the report from Hastings' group and would not comment until they have a chance to review it, said Chris Tollefson, press secretary for the U.S. Fish and Wildlife Service.

Signed into law by President Richard Nixon in December 1973, the act has resulted in additional protections for more than 1,500 plants, insects, mammals, birds, reptiles and other creatures, according to the Fish and Wildlife Service.

Throughout its history, the law has faced criticism from business interests, Republicans and others. They argue actions taken to shield at-risk species such as the northern spotted owl have severely hampered logging and other economic development.

Those complaints grew louder in recent months after federal wildlife officials agreed to consider protections for more than 250 additional species under settlement terms in lawsuits brought by environmental groups.

Included in the settlement was the greater sage grouse, a chicken-sized bird that has been in decline across large portions of its 11-state Western range. A final decision on whether to protect sage grouse is due next year and could result in wide-ranging restrictions on oil and gas development, agriculture and other economic activity.

The endangered act was last amended in the 1980s. Given the current level of rancor between Democrats and Republicans, academics who track the law were skeptical that the latest calls for change would succeed.

"Both sides have enough power to prevent something happening that they don't like. But nobody has enough power to pass anything," said Dale Goble, an expert on the act who works as a law professor at the University of Idaho.

Goble added that the main reason some species linger for decades on the endangered list is a shortage of federal money to help pay for their recovery.

Vanderbilt Law School professor J.B. Ruhl said previous attempts to reform the Endangered Species Act in the 1990s and again last decade failed. Regardless of the merits of the latest proposal, Ruhl said the topic remains a "third rail" many politicians are unwilling to touch.