Matt Schuth tramped across the Minnesota Landscape Arboretum's grasslands while two dozen birders and plant lovers focused on his every move.

Suddenly he pointed to the sky and called out "dickcissel." The yellow-chested bird dipped in and out of tree branches. In unison, arms raised binoculars to get a closer look.

Next, Schuth stopped at one of the bluebird boxes and lifted the door, revealing a nest of tiny blue eggs. "Don't be afraid to look," he said. "It's not going to bite." As if on cue, a pair of bluebirds landed on a nearby nest box. "Oh, beautiful," murmured several walkers as they raised their cameras for the photo opp.

Schuth was leading one of his popular Walks With Matt. During the two-hour trek, he shared stories into which he wove facts, trivia, humor — and even a little poetry from Henry David Thoreau. He exuded excitement in every sentence.

"The Eastern kingbird is a very messy house builder, but aggressive when it comes to defending their home," Schuth said. "They've even knocked my hat off when I was checking a nest."

The hikers praised his encyclopedic knowledge about the culture, science and history behind any topic. "I try to keep it light and funny," said the 69-year-old. "Each plant and bird has its own story."

Nature's marvels elicit delight or disdain on the walks, he said. "When people see dozens of blooming yellow lady slippers — or rare birds — you can feel the excitement level." But when walkers cringe at a mass of garter snakes slithering to a rock den, "I remind them that snakes eat all kinds of insects," he said.

Schuth's infectious passion for nature is why his walks always fill up, said Karen Sowizral, a volunteer assistant. "Matt still finds beauty and wonder even in the things we've seen a thousand times," she said. "It's never old hat for him."

His outdoor expertise springs from growing up on a farm outside Wabasha, Minn. "I assumed that all 12-year-olds knew about animals, birds and wildflowers," he said.

After graduating from Winona State University, he was on the staff at the arboretum's Horticultural Research Center for 30 years before retiring in 2012. Now as a volunteer, he leads about 12 walks a year on topics such as wood ducks and wrens, mushrooms, and sights and sounds of the prairie.

To register for upcoming walks, go to arboretum.umn.edu. One word of caution: It might be addictive.

"If you fall in love with nature," he said, "you'll never be bored a day in your life."

Schuth will sign his book "Nature at Our Doorstep" (Nodin Publishing, $22.95), from 1 to 2 p.m. July 29 at the Arboretum Gift and Garden store.