The battle over the big, bad wolf continues.

Buried in the dry language of a newly released budget proposal for the U.S. Department of the Interior is a line that you could easily miss: a directive to study the genetics behind the Mexican gray wolf and another species, the red wolf.

The idea is to have the U.S. Fish and Wildlife Service survey these wolf populations to find out if, in fact, these wolves comprise a distinct subspecies and species, respectively.

Sounds uncontroversial enough.

But environmentalists say this proposal strikes at the heart of conservation efforts for the endangered wolves. Currently, the Mexican gray, native to the Southwest, is classified as a subspecies of the gray wolf; the red wolf, found in the southeastern U.S., is its own species entirely. Both are critically endangered.

Yet the Endangered Species Act of 1973 is mute on whether a hybrid animal qualifies for protection, which worries conservationists. A new genetic interpretation of the wolves' origins could put their protected status in jeopardy.

The language of the budget bill would require the Fish and Wildlife Service to determine within 60 days whether these are genetically unique species, and then submit a report to Congress within a year.

A conservationist with the Center for Biological Diversity, based in Tucson, called the proposed scientific review "mischief-making by House Republicans."

"First, it’s a waste of agency resources and time, because there’s no question about (and there hasn’t been a question about) whether the Mexican wolf is a subspecies," Michael Robinson told Phoenix New Times.

Robinson says that a handful of recent studies have concluded that these are genetically distinct canines. Researchers from the Fish and Wildlife Service even reaffirmed the Mexican wolf's genetic status in a report just five years ago.

Several Arizona Republicans are at the forefront of the fight to reduce protections for the Mexican gray, commonly known as the lobo. Congressman Paul Gosar, who represents Arizona’s 4th Congressional District, co-sponsored a bill in 2015 that sought to override the Fish and Wildlife management program and kick the Mexican wolf off of the Endangered Species List.

A spokesman for Gosar did not respond to a request for comment from New Times.

The budget proposal on studying wolf population arrives during a multi-pronged effort by the Trump administration and Congressional Republicans to roll back environmental protections. On June 29, the U.S. Fish and Wildlife Service released a revised plan for Mexican wolf recovery, which was cheered by advocates of curtailed wolf reintroduction. Ranchers and the livestock industry are generally opposed to more robust wolf populations.

Jim deVos, assistant director for wildlife management in the Arizona Game and Fish Department, told New Times at the time that the new Mexican wolf recovery plan "strikes a middle ground position that meets the Endangered Species Act requirement to accomplish recovery."

And on Wednesday, the House Committee on Natural Resources was center stage in a fight over changes to the Endangered Species Act's mandate. Arizona Congressman Raúl Grijalva, the senior Democrat on the committee, didn't mince words on the proposed revisions, which would hand more power to the states to de-list species. He said the changes jeopardize an environmental act that's working fine.

“Despite years of Republican efforts to pass bills weakening the act and cut funding from agencies that protect and recover imperiled American wildlife, 99 percent of listed species have continued to survive, and 90 percent are on schedule to meet their recovery goals,” Grijalva said.

There are only around 110 Mexican gray wolves in the U.S. Robinson said the revisionist science as to whether these are valid species could derail a delicate recovery process.

“It’s almost as thought they’re putting a stick in the spokes of a moving bicycle, which is troublesome," he said.

