If it's an amphibian, it's Sonja Rosas' friend.

The 18-year-old Winchuck River Road resident is wild about newts, frogs and salamanders.

"I saw my first Pacific chorus frog when I was 11 and thought that was the most amazing thing," she said.

Rosas moved from Portland to Brookings in August with her parents and siblings, and she's discovered an entire amphibian world on the grounds of their new home.

Besides the Pacific chorus frogs andndash; which she can hear, but hasn't spotted yet andndash; there are California slender salamanders, roughskin newts, northern red-legged frogs and ensatina salamanders. That kind of diversity means the local ecosystem is healthy, Rosas said, because amphibians are considered biological indicators.

When toxins or other problems hurt the ecosystem, amphibians are among the first casualties.

Susan Barnes, a wildlife biologist with the Oregon Department of Fish and Wildlife, agrees with Rosas' assessment of amphibians as indicator species, a type of "canary in the coal mine" that reflect environmental problems.

Barnes called the California slender salamander "a rare find, a notable species." She said it is found only on a "very tiny sliver of the Southern Oregon Coast," in humid, wet conditions near redwood forests.

The five species' presence on the Rosas property is due to a wildlife pond, stream and woodpiles that provide habitat on the acreage.

"Newts and frogs breed in the pond, and all four species rely on woodlands for refuge and food," Rosas said.

She knows her stuff because of some valuable internships while living in Portland.

Rosas surveyed the numbers of Oregon spotted frogs living near Mount Adams while interning for the Oregon Zoo in 2008. After that, she investigated the populations of various amphibians in the Portland urban area as an intern for the Portland Parks and Recreation Department's Environmental Education Program.

"It was so much fun," she said of the latter experience. "I loved it."

Surprisingly, Rosas said, she found that amphibians thrive less than 500 feet from Portland's busy roads. One species, the red-legged frog, is declining there but is plentiful in the Brookings-Harbor area.

She was home schooled and credited her mother, Carmen, will allowing her to get the internships in Portland. Rosas said her mom drove her places she needed to be, and encouraged her to pursue her interests in nature, including stints at the zoo and park department.

Rosas is considering volunteering in local schools to teach students about amphibians andndash; or inviting classes to her family's home to host a field trip on the grounds.

On a recent afternoon, she dipped a young frog from a lily-covered pond next to the house. Rosas explained the pond gives some species of frogs and newts a place to breed and the vegetation in the water is a place for them to attach eggs.

She encourages local residents to maintain wood piles or build a pond on their property to provide habitat for the tiny creatures. And Rosas urges people to minimize their use of herbicides and pesticides to "be an amphibian ally."

It's OK to pick up amphibians to take a close look, she said, but do so with wet hands and don't bring them into the house to put in a terrarium or other container. She suggests placing them on a leaf while viewing, then leaving them in their natural habitat.

Rosas said she will be happy to answer any questions that people have. She can be reached at sonjarosas@gmail.com.

Searching for salamanders, some of which are less than 3 inches long and resemble worms, can be an exciting game, Rosas said. She turned over pieces of wood in her backyard for a glimpse of life beneath.

"Don't shy away from nature. Touch it and fall in love with it," Rosas said. "It's best to just observe in the wild and be respectful."

She has lots of patience when it comes to viewing the natural world. Rosas has been known to sit for hours watching a frog, finally seeing it snap at a passing fly.

"They are ambush hunters," she said.

Rosas hopes to become a field biologist and has tentative plans to attend Evergreen State College in Olympia, Wash., because of its strong outdoor education program.

For now, roaming the yard surrounding her home is an education in itself.

Besides being a source of joy.

"You come out here and it's totally secret, but if you poke around there are things there," she said. "It's a great excuse to go out and play, no matter how old you are.

"It's incredible. For me, it's like seeing big game in Africa."