When you’re walking outdoors, whether it’s along a sidewalk or forest path, what catches your attention? Maybe it’s the piercing call of a bluejay, a cluster of honey-colored mushrooms or the vines crawling up the side of a brick building.

Pick just one thing in nature. Take a step toward it. Look closely. What do you see?

These observations, however big or small, are at the heart of “The Naturalist’s Notebook,” co-authored by Bowdoin professor and biologist Nathaniel Wheelwright and best-selling author Bernd Heinrich. Published in September by Storey Publishing, the 208-page hardcover book sells for $19.99 and includes six instructive chapters on how to record nature observations, as well as a blank five-year calendar journal for the reader to try their hand at the practice. In addition, the book is filled with illustrative art by Heinrich including vivid watercolor depictions of plants, fungi and animals of the Northeast.

“Follow what makes you heart beat a little bit faster,” Wheelwright said in a recent interview about the book. “It might be flowers. It might be butterflies, birds, mammals. Start with something you might have a particular interest in.”

The Bass Professor of Natural Sciences at Bowdoin College, Wheelwright teaches a variety of ecology courses, including a popular course on bird song. And for the past 30 years, he’s kept a systematic calendar journal to record his own observations, whether he’s studying tropical cloud forests in Costa Rica or gardening at home in Brunswick. Through “The Naturalist’s Notebook,” he shares that lifelong practice with readers, with the idea that closer observation of nature not only deepens a person’s connection with their surroundings but also fosters a greater appreciation of the environment and conviction to protect it.

“I’ve long been really passionate about conservation,” Wheelwright said. “It just seemed like a good time in my career, as I’m heading toward retirement from classroom reaching, why not take what I’ve trained myself to go most of my life and see if I can reach a broader audience, a difference audience.”

For the project, Wheelwright enlisted fellow biologist Heinrich, author of several best-selling books including “A Year in the Maine Woods” and “Why We Run: A Natural History.” He, too, has compiled an impressive collection of nature journals.

“I’ve off and on — maybe mostly on — all of my life, been scribbling in some sort of journal,” Heinrich said in an email interview from his off-the-grid cabin in Weld, Maine. “I still treasure mine. For example, [I have a journal from] when I was 22 years old and spent 13 or so months in Africa. It’s like keeping a memory without using up extra brain space that’s better used for other things, and I can consult it any time.”

Both authors intend for this book to be for anyone and everyone — the biologist, student, backyard birder and city dweller.

“I think we’re all naturalists, and by that I mean maintaining an active interest for physical contact with the natural world,” Heinrich said. “Nature is the source of our survival, and to be interested in it, to understand it, promoted our lives for most of our history.

Wheelwright echoed this concept, that humans are naturally inclined to observe and interact with the environment.

“I think, whether people are aware of it or not, we respond to the scent of a rose and a howl of a wolf in a very deep way — or the sight of a spider,” Wheelwright said. “This is very much encoded, I think, in our genes our our evolutionary history of interacting with nature.”

“Natural selection has pretty much orated a love of nature and a sense of awareness of nature in our genes,” he continued. “It’s just, we don’t the opportunity in our busy modern lives to put those genes to work. I don’t think it’s a big stretch to go from someone who knows nothing about nature, to go to being [a person who says], ‘I feel more fulfilled, more connected, I feel happier or healthier because I heard a bird sing or a butterfly fly by.”

The calendar journal provided in “The Naturalist’s Notebook” offers a spreadsheet-style format for briefly recording observations over the course of five years, which makes it easier to detect patterns, as well as changes, in the environment. This calendar journal can easily be paired with standard journals that have room for more in depth, detailed writing and, if you’re like Heinrich, artwork.

“Don’t try to squeeze into these little tiny squares your beautiful watercolors and deeper thoughts,” Wheelwright said. “Use the squares to cross reference a deeper journal you might have. Make a note on the date you saw it, then see page 47 in your watercolor book.”

In their collaboration, Heinrich supplied Wheelwright a thumb drive containing approximately 900 watercolor paintings and drawings. This artwork included the eggs of ovenbirds, sparrows and sandpipers; botanical drawings of winterberry, bloodroot and speckled alder; and sketches that display the differences between the nests of doves, hummingbirds, swifts and bank swallows. At least 90 examples of this artwork decorate the chapters and journal calendar of “The Naturalist’s Notebook.”

“After I started writing, I realized often that I had not really seen it until I could paint it,” Heinrich said. “It seems to me that the closer I look, the more I understand and see connections.”

In addition to contributing artwork to the book, Heinrich wrote two of the six chapters, including an essay on illustrating nature. Wheelwright wrote the rest, touching on many different topics, including the use of technology in nature study; statistical analysis and data collection; and natural history events that can be easily monitored. And perhaps most helpful is his 10 guidelines to becoming a more observant naturalist, the last of which is: “Put knowledge into action.”

And that’s Wheelwright’s next step.

In an effort to reach an even broader readership, he aims to create and publish a low-cost Spanish version of “The Naturalist’s Notebook.” By doing so, he hopes to further spread the practice of nature journaling, a form of citizen science that he believes has the power to expand our knowledge of the world’s natural resources and promote conservation worldwide.

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Aislinn Sarnacki

Aislinn Sarnacki is a Maine outdoors writer and the author of three Maine hiking guidebooks including “Family Friendly Hikes in Maine.” Find her on Twitter and Facebook @1minhikegirl. You can also...