What's living in your backyard? There may be more than squirrels, deer, and coyotes. When Bolton resident Janet Pesaturo set out to visit Harvard Conservation land one snowy February morning.

She was hoping to find some fox tracks, or perhaps some evidence of the otter she suspected was living in the wetland habitat.

However, as she made her way across the habitat, she stumbled upon something rather unexpected.

The tracks of a bobcat, confirmed by the length and width of the paw prints. Pesaturo is well qualified to recognize bobcat prints: she is the founder of the Nashaway Trackers, a group of volunteer animal trackers in Bolton, Maynard, Shrewsbury, and Stow.

"Some of us do a lot of tracking just for fun, and we do it anywhere — in our backyards, on local conservation land, or at other interesting locations, such as the Quabbin Reservoir," she said in an e-mail interview.

Pesaturo began the group about five years ago. Members are trained to document tracks and signs of mammal activity with Keeping Track, a non-profit organization that encourages volunteer tracking groups to share the data they collect with their local conservation organizations.

Some areas are more promising than others for tracking, she said. "Almost any wetland is a hot spot for animal activity, especially beaver ponds, so that's the type of habitat we gravitate to when tracking for fun," Pesaturo said. The Nashaway Trackers have conducted mammal surveys and wildlife monitoring for local towns and conservation groups. They have tracked carnivorous mammals such as bobcasts, fishers, and otters.

At the Quabbin Reservoir in Belchertown, they have tracked moose and black bear.  Two years ago, they conducted a mammal survey in Harvard, and this year they are surveying the Mt. Pisgah area for the Sudbury Valley Trustees.

"[W]e try to keep our project areas local, because we have to make many trips to the property," Pesaturo said. "Most people in the group are from Bolton, Harvard, and Stow, so we try to get projects in or near those towns." The Nashaway Trackers also offer educational programs in association with local conservation organizations and commissions, such as nature walks for both adults and children.

Pesaturo also offers slide shows on tracking mammals in Massachusetts and has written some articles for the Bolton Conservation Trust newsletter. She shared her story about tracking the bobcat for the winter 2007 issue.

The Nashaway Trackers range from the experienced tracker to the curious beginner. Pesaturo estimates that between six and seven members consider themselves serious trackers. Some trackers enjoy volunteering to help with specific projects for conservation organizations, while others track on their own. There are also members who communicate through the group's blog.

"Most of us are interested in all aspects of nature, from birds to mammals to plants, and everything in between, so we look at all of that when out for fun," said Pesaturo. Susan Fly, a Bolton resident and a self-described "lifelong nature lover," has been a member of the Nashaway Trackers since it began.

"I joined because I was interested in learning how to better identify the animal signs and tracks that I regularly observed while in the woods," said Fly, who can recognize evidence of wildlife in her own backyard thanks to her training.  Fly claimed to have observed signs of mammals such as rabbit, fox, and beaver while walking her dog. "There is an abundance of wild animals right in my own neighborhood," she said.

Fly said she has gained invaluable knowledge due to her involvement with the Nashaway Trackers and that her membership "has enabled me to help local conservation groups make decisions about land use." But it is perhaps the simple observation of wildlife that is the greatest reward "Coming across the feathery imprint of a hawk touching new snow as it reaches to snatch a rodent is amazing every time I see it," she said.