— The volunteers of the Maryland Amphibian and Reptile Atlas project leave no log unrolled, no stone unturned in their quest to document the state's dirt dwellers.
When the earth is moist after a soaking rain and the temperatures whisper spring, the herp patrol — short for herpetology — spreads out in search of slithering, hopping, plodding critters along the fringes of farm fields, sunning themselves on pond rocks and making new burrows at the edges of vernal pools.
These amateur census takers aren't picky. They'll even settle for those unfortunate and immobile residents of the asphalt — road kill — to prove that a species is alive and kicking some place nearby.
Now in the fourth year of the five-year effort, the atlas project was designed by the Natural History Society of Maryland and the Department of Natural Resources to establish a baseline of the places where amphibians and reptiles live. Biologists and policymakers will use the information to devise conservation and protection strategies.
The results of the 2009-2014 study will be compared to a map compiled over 75 years and published by the Natural Historical Society in 1975.
"Amphibians are a good indicator of how we're treating the planet," said Glenn Therres, a DNR wildlife biologist who supervises the project. "If we repeat this survey in 20 years, we'll know how we, and they, are doing."
The U.S. ranks ninth in the world for amphibian diversity, and the southeastern region of the country is known for its salamander diversity, said Heather Cunningham, the herpetologist who leads the atlas project.
"With that comes a certain responsibility to conserve and be aware of changes," she said. "They may not be the cutest megafauna out there — like the pandas — but they are important."
On a rare, warm afternoon last week, Therres made the rounds in Queen Anne's County, map spread across the dashboard, hoping to find some critters that should be there, given historical records. He stops mid-sentence, rolls down the window and cocks his head toward the opening. "Hear that?" he asked.
Across a field, something sounding like a thumb rubbing across the teeth of a comb is making its presence known.
"That's a New Jersey chorus frog. We just added a species," he said as he made a notation in a blue spiral notebook. "Boy, we needed that."
At first glance, the project's goal seems simple: Find specimens of Maryland's more than 90 species of frogs, toads, salamanders, turtles, lizards and snakes in their native territory. But when you divide the state's 9,707 square miles into 1,293 grid blocks, the task becomes, "daunting," said Howard County coordinator Sue Muller. "At the end of the third year, I was surprised by how many blank squares there were."
A lot of land is privately held, limiting volunteers to what they can hear or see from the roadside. Nothing much moves in winter, and a lot of the summer slithering and hopping happens after dark.
"Let's face it, there's not an army of people out there who want to go traipsing around, looking for frogs," Therres said.
As a result, huge swaths of Baltimore County, including Patapsco Valley State Park, and the city remain blank slates.
Enter volunteers such as Muller, a 27-year employee of the Howard County's Department of Recreation and Parks, who has recruited a battalion of 300 people who have not only exceeded their goals by blanketing the county's four grid squares but have branched out to help in Garrett, Somerset and Montgomery counties.
"This is a vital tool," Muller said. "It's important to know what you have and where you have it. As a resource manager, how can you protect something if you don't know what you've got and where it is?"
Participation doesn't require a keen ear to distinguish a spring peeper from a New Jersey chorus frog or a childlike enthusiasm for ooze.
"It can be a turtle crossing the road that you see on the way to the grocery store or something in the backyard," said Cunningham. "You don't even have to know what it is. We've got people to do that."
"Just being able to snap a picture will do," said Muller, who tries to team newcomers with experienced herpers. "And they don't have to be National Geographic-cover quality, either."