A network of trail cameras in the Chequamegon-Nicolet National Forest could help restore populations of Wisconsin's only state-endangered mammal, the American marten.

State conservation biologists began deploying cameras among 120 different sites in December to capture photos of martens, an elusive member of the weasel family that inhabits older forests in northern Wisconsin. They will use the data to track individual martens by their unique fur patterns, according to the Wisconsin Department of Natural Resources.

Cameras are a cheaper, less invasive tracking method than capturing and marking animals. They will also provide a more reliable method than snow track surveys, which require ideal snow conditions.

Using trail cameras, conservation biologists will be able to identify martens across multiple years, generating more reliable estimates of population size and annual survival. The cameras may reveal more about the small mammal's habits so the DNR and conservation partners can refine strategies for recovering the species.

American martens, which weigh 1-3 pounds and measure up to 2 feet long, were abundant in northern Wisconsin before European settlement. Trapping and habitat destruction led to their disappearance from the state around 1925. The American marten was placed on the state endangered species list in 1972, according to DNR conservation biologist Carly Lapin.

There have been multiple attempts to reintroduce American martens in Wisconsin since the 1950s with varying degrees of success.

"American martens are an important species in Wisconsin because they are known as an 'umbrella species,'" Lapin said. "Managing Wisconsin forests to improve habitat for American martens will also improve habitat for a wide variety of other species that also rely upon older forests."

The trail camera project is being led by the DNR Natural Heritage Conservation, which is funded in part by the Endangered Resources Fund. People can donate to the fund on their Wisconsin income tax form; those donations are matched by the state.