No one is sure whether wolves live in the Maine woods, but wildlife biologists agree that without federal protection, these predators that once ruled Northeastern forests will never stage a successful comeback.

This week, the National Wildlife Federation announced its plan to sue the U.S. Fish and Wildlife Service for violating the Endangered Species Act by not taking these wolves into consideration.

In April, the service decided to downgrade gray wolf protection from endangered to threatened in a giant region stretching from Wisconsin to Maine. The decision was based mostly on the fact that wolves have rebounded in the Great Lakes region, where they have established healthy populations and migrated into new territories.

Federal biologists decided the recoveries were enough to remove protection from wolves across the entire eastern United States – which Peggy Struhsacker, a spokeswoman for the federation, says is wrong. She believes Northeastern wolves must be considered independently to have any chance at recovery.

Once an animal is listed as threatened, it can be removed from federal protection entirely after just a year, which is what many wolf advocates fear the federal government plans for wolves, she said.

“That will leave it totally in the hands of the states to take care of these animals, which the states can’t afford,” Struhsacker said.

The last time the service considered writing a wolf recovery plan for the Northeast, in 2000, many leading scientists supported the effort, Struhsacker said.

But in rural states like Maine, the debate was political. Discussions focused on whether federal involvement could lead to wolf reintroduction programs, which are bitterly opposed by the state’s powerful hunting lobby and by many livestock farmers.

In Maine, wolves have minimal state protection because the state Department of Inland Fisheries and Wildlife does not recognize the animal’s presence. Limited state funding does not allow for the sort of large-scale study necessary to prove, once and for all, whether wolves inhabit Maine’s woods, said Ken Elowe, head of the state’s wildlife division.

The NWF believes federal biologists should have considered the Northeast as a distinct population segment – a term used by biologists to indicate a unique population. For example, the Atlantic salmon that were declared federally endangered in a handful of Down East rivers were classified as a distinct population segment.

Over the past decade, two wolf-like animals have been shot in Maine, and countless other sightings have been tracked by the Maine Wolf Coalition. Last year, two wolves from Quebec were spotted a few miles from the Vermont border.

Historic records prove wolves once abounded throughout the region, and studies have indicated that the Northeast, particularly Maine and New York, still has thousands of acres of prime wolf habitat.

A natural migration only may be a matter of time.

The U.S. Fish and Wildlife Service actually hired a half-time employee to investigate wolf sightings this summer, collecting scat and conducting howling surveys in Northern Maine, but the evidence was – at best – inconclusive, said Mark McCollough, a wildlife biologist based at the service’s Old Town office.

Biologists can’t create a distinct population segment without proof of a population, he said.

“For a population to be identified, we would have to have more than the single animals we’ve been seeing,” he said. “We would likely need to see a group of animals, or some evidence of reproduction.”

Wolf advocates argue that the federal government hasn’t dedicated enough resources to wolves in the Northeast. The service failed in its refusal to look into the data in the Northeast, they said.

At the very least, the service should have provided a scientific explanation of why a Northeast distinct population segment was not created, Struhsacker said.

“These questions have to be answered,” Struhsacker said. “It’s mind-boggling, the amount of work that has to be done.”

Thursday, the federation notified the U.S. Department of the Interior a lawsuit will be filed within 60 days – a formal step required by law. And unless the U.S. Fish and Wildlife Service offers to reopen the wolf classification and create a distinct population segment for the Northeast, the case will go to court, Struhsacker said.

A similar complaint about Canada lynx reclassification is pending in federal court, and environmentalists have been successful in forcing broader protection for a rare lizard in California.

“There are some precedents to hang this on,” said John Kostyack, a lawyer for the federation.

If the case is successful, federal biologists will be required to research wolf populations here and write a recovery plan, which would likely take several years and could include everything from habitat protection measures to wolf reintroduction.