The wolf—once quite literally a symbol of evil—was very nearly driven to extirpation in the United States before conservation measures began to offer protection to the iconic predators. That protection culminated in the Endangered Species Act of 1973, which made it a federal crime to kill any species listed as endangered. In recent years, populations in several regions (including Yellowstone National Park, where they were notably reintroduced in 1995) have been steadily recovering.

As a result, the question of whether the wolf should be removed from the endangered species list has been broached. In fact, the US Fish and Wildlife Service has tried to do just that three times in the last nine years. Each time, conservation groups have challenged the move in court and succeeded in blocking it. The issue is complicated for a number of reasons; for starters, there are a number of separate populations in different states. Some populations may be ready to be delisted, while others may not be sustainable without protection.

When wolves lose endangered species status, management reverts to the state level, where attitudes towards wolves vary widely. For example, the director of the Utah Department of Natural Resources recently told the legislature there that bringing back wolves would be like "the resurrection of T. rex and turning him loose on the landscape." He added that wolves were "the perfect biological weapon" employed by anti-hunting groups. Last year, the governor of Idaho ordered state agencies to stop enforcing federal protections of wolves, stating that the reintroduction of wolves "was a tragic example of oppressive, ham-handed 'conservation' at its worst."

As part of the recent federal budget showdown, legislators from Montana and Idaho attached a rider to the budget bill ordering the Fish and Wildlife Service to delist wolves in those states without the possibility of judicial review. You can probably predict how these states will choose to manage their wolf populations.

Several wolf researchers recently published a policy article in Science proposing a new view of state responsibilities toward wolves (with one author discussing it on his blog.) They argue that there is a very long common law history for wildlife falling under the umbrella of the public trust doctrine—in short, wildlife belong collectively to the citizens of the state. The state, then, is obligated to preserve wildlife for the benefit of the public. This duty has been cited by the US Supreme Court on several occasions, including cases involving wildlife as well as navigable waterways.

One reason that many conservation groups have opposed the delisting of the wolf is that there appears to be no way to force states to preserve wolf populations. The researchers consider the public trust doctrine to be a duty that compels states to ensure a sustainable population of wolves or, indeed, any species.

That would be a big step, because as the authors put it, "formal recognition of a duty to preserve species under the wildlife trust would, at minimum, require states to maintain a viable population of wolves. Such an acknowledgement from states could help assuage fears that state-led wolf management will lead to a second wave of wolf eradications and could move debate about population baselines and distributions back into the scientific—as opposed to political—arena."

Science, 2011. DOI: 10.1126/science.1207803 (About DOIs).