Federal wildlife authorities who once were so confident the gray wolf could survive without Endangered Species Act protections now say they didn't do all their homework as completely as they should have.

Back in February, Lynn Scarlett, a deputy to Interior Secretary Dirk Kempthorne, announced the government's intention to remove ESA protections from the gray wolf in the greater Yellowstone ecosystem, saying that, "The wolf population in the Northern Rockies has far exceeded its recovery goal and continues to expand its size and range. States, tribes, conservation groups, federal agencies and citizens of both regions can be proud of their roles in this remarkable conservation success story."

While there were an estimated 1,500 or more wolves and at least 100 breeding pairs in Montana, Idaho, and Wyoming, conservation groups sued the government to stop the delisting, arguing that a sound recovery program can't sustain itself, genetically, without two or three times that number.

In July a federal judge in Montana agreed with the conservationists and issued a preliminary injunction to put a hold on the hunting of wolves until a trial could be held to fully explore the groups' claims that the Interior Department was premature in removing ESA protections from the wolf in the greater Yellowstone ecosystem.

In his ruling, U.S. District Judge Donald Molloy stated that, "In my view, Plaintiffs are likely to succeed on the majority of the claims relied upon in their request for a preliminary injunction. In particular, (1) the Fish & Wildlife Service acted arbitrarily in delisting the wolf despite a lack of evidence of genetic exchange between subpopulations; and (2) it acted arbitrarily and capriciously when it approved Wyoming’s 2007 plan despite the State’s failure to commit to managing for 15 breeding pairs and the plan’s malleable trophy game area.

"In both instances, the Fish & Wildlife Service altered its earlier position without providing a reasoned decision for the change based on identified new information."

But now a trial might not be necessary, as U.S. Fish and Wildlife Service officials have decided to withdraw their delisting proposal.

Ed Bangs, who long has overseen the wolf recovery program for the agency, told the Idaho Statesman that the agency didn't clearly lay out why it thought wolves in the ecosystem could indeed survive without ESA protections.

"There's going to be a thorough, fine-toothed comb going through it to decide what we can do better," he told the newspaper.