(Adds Weyerhaeuser comment, reaction from environmental group, conservative legal group)
By Lawrence Hurley
WASHINGTON, Nov 27 (Reuters) - The U.S. Supreme Court on Tuesday handed a victory to timber company Weyerhaeuser Co and other landowners seeking to limit the federal government's power to designate private land as protected habitat for endangered species in a property rights case involving a warty amphibian called the dusky gopher frog.
The court, in a 8-0 decision written by Chief Justice John Roberts, threw out a 2016 ruling by the New Orleans-based 5th U.S. Circuit Court of Appeals that had favored the U.S. Fish and Wildlife Service, finding the lower court gave the government too much leeway. The justices sent the case back to the 5th Circuit lower to reconsider.
In 2012, the agency decided to include private land where the frog does not currently live as critical habitat, potentially putting restrictions on future development opportunities. Weyerhaeuser harvests timber on the Louisiana land in question and was backed in the case by fellow landowners and business groups including the U.S. Chamber of Commerce.
The frog, found only in southern Mississippi, also previously inhabited Louisiana and Alabama. The U.S. government identified the Louisiana land partly owned by Weyerhaeuser, which is based in Washington state, as meeting the criteria for the frog's habitat under the federal Endangered Species Act.
Roberts wrote that the appeals court's broad definition of what can be defined as "critical habitat" under the Endangered Species Act was incorrect, with chief justice making clear that there are limits on the scope of government authority to make such determinations.
The chief justice also said the challengers should be allowed to contest whether the government conducted a rigorous analysis of the costs and benefits when designating the land as critical habitat. Weyerhaeuser has said that, among other things, the government did not account for the costs of planting pine trees that would be required for the frogs to flourish.
The Supreme Court did not rule on whether land that needs modifications to support a protected species, like the property in question, can constitute habitat, meaning the ruling may be limited in its impact on other similar cases.
"While we're disappointed, the ruling doesn't weaken the mandate to protect habitat for endangered wildlife," said Collette Adkins, a lawyer with the Center for Biological Diversity, an environmental group that backs the designation.
The Fish and Wildlife Service described the frog as darkly colored and moderately sized with warts covering its back and dusky spots on its belly.
The Pacific Legal Foundation, a conservative legal group that represents Edward Poitevent, whose family owns most of the land in question, hailed the ruling.
"The nation's hardworking property owners can rest easier tonight knowing government-sponsored land grabs just became a lot more difficult," said Mark Miller, one of the group's lawyers.
"It was good to have the unanimous court agree with Weyerhaeuser on both of its legal arguments," added Weyerhaeuser's lawyer, Timothy Bishop.
Conservative Justice Brett Kavanaugh did not participate in the case, which was argued before President Donald Trump's nominee was confirmed by the Senate last month.
The agency's critical habitat designation covered the tract of 1,544 acres (about 625 hectares) of private land in Louisiana as well as nearly 5,000 acres (about 2,025 hectares) in Mississippi. The owners of the Louisiana land filed a legal challenge to the designation, saying it would infringe on their rights to use the property as they see fit.
The frog has been listed as endangered under the Endangered Species Act since 2001. Critical habitat is defined as an area essential to the conservation of a species that may require special management or protection.
(Reporting by Lawrence Hurley; Editing by Will Dunham)