I was sitting in a sunny spot on my porch reading Dara McAnulty's "Diary of a Young Naturalist" when a shadow passed the window, briefly blotting out the light. I looked up to see a hawk swoop into our maple tree, a small wriggling creature trapped in its claw.

What kind of hawk? I don't know. What kind of prey? I can't say, but I'm betting McAnulty could have, had he been there. Devoted to the natural world, he doesn't just observe nature, he inhabits it fully, paying close attention to even the smallest of things.

"Diary of a Young Naturalist" is a remarkable book, the most moving memoir I have read in years. Now 17, Dara wrote it when he was 14, and his knowledge at such a young age amazed me — not just his understanding of the natural world, which is immense, but of literature (feeling the "peaty cold" of a bog pond reminds him of a Seamus Heaney poem), of Irish history and legends, of music and politics. His writing is clear and honest, laced with analogies from nature. (A goshawk chick "looks like an autumn forest rolled in the first snows of winter.")

Growing up in County Fermanagh in Northern Ireland, Dara was besotted by the natural world as a very small child. At 4, he went with his parents to Waterstones bookstore, "where I laid out the coins on the counter for my first field guide, Roger Phillips' 'Mushrooms and Other Fungi of Britain and Europe.' "

He is the oldest of three children in a loving family. "Together we make for an eccentric and chaotic bunch," he writes. "We're as close as otters."

Their father, he says, is the odd man out — a conservation scientist, he's the only one in the family who is not autistic, "the one we rely on to deconstruct the mysteries of not just the natural world but the human one, too."

Autism is an important theme of this book, as Dara writes about his difficulties making small talk or forming friendships, and he speaks almost matter-of-factly about being constantly bullied. But it is not matter of fact; he thinks of taking his own life, he wonders if bullying has traumatized him.

In nature, he feels secure. "No one can put me down or kick me in the face. I'm safe down here with the buttercups and meadowsweet."

Dara is fascinated by the smallest dung beetle or the largest soaring raptor; he knows the names of plants and flowers and can identify birds by their song. In one beautiful scene, he and his mother drive out to view a murmuration of starlings, "funneling and sweeping" across the sky.

He laments that modern farming practices mean that ground-nesting birds can no longer raise chicks and are now endangered — the big tractors just plunge ahead, chewing up all that is front of them.

The book covers one year, from early spring through the end of winter. During that time Dara moves with his family to County Down (excruciatingly difficult for a boy who needs routine), spends most of his time outside observing "the creeping, crawling, fluttering wild things," and takes his first steps toward becoming an environmental activist.

County Down proves a safe place for him, and I nearly wept when I read, late in the book, that the first semester of school there, where no one punched him or bullied him or knocked him down, was "the best four months of school I've ever had."

Dara's autism, perhaps, influences his incredible focus — more than once he writes about being so captivated while watching fish or birds or bugs that he fails to hear his younger brother tell him he's heading home, fails to notice that a driving rain is saturating his clothes or that the December river water is chilling his bare feet until they turn blue.

What drives this book is Dara's fierce passion — for his family, for the out of doors, for sharing his knowledge and enthusiasm with others (even as he fears they will mock him).

"We're not separate from nature," he writes. "We are nature."

And now as I walk through my neighborhood and look at the many glorious, tangled gardens planted for pollinators and bees, or the manicured lawns with signs warning of chemical weed killers, or the great-horned owl family that roosts in the pines, I try to look with Dara's eyes and I see it all new.

Laurie Hertzel is the senior editor for books at the Star Tribune. @StribBooks

Diary of a Young Naturalist
By: Dara McAnulty.
Publisher: Milkweed Editions, 222 pages, $25.