In the span of a human lifetime, gray wolves have re-established their presence in Montana’s mountains and forests.

Human settlers had driven most of the predators out by the early 1930s. But beginning in the 1970s, Endangered Species Act protections and re-introductions fostered a recovery. Montana’s wolf population has grown from about 50 confirmed animals in the 1990s to nearly 500 today.

The recovery is often hailed as a success story for wildlife management. But now, the wolf population’s growth is making management tougher.

Wildlife planners need a sense of how many wolves they need to protect. In past years, the U.S. Fish and Wildlife Service and Montana Fish, Wildlife and Parks have gotten that information using a minimum count — a physical survey of animals, one that assumed some would be missed.

“Minimum counts worked really well back in the day when there was a lot of money available for monitoring from the federal government, and when the wolf population was small enough that you could go out, and track, and count wet noses,” explained Mike Mitchell, unit leader of the University of Montana’s Cooperative Wildlife Research Unit.

via: Bigfork Eagle , Montana prepares to model its wolf populations