Bernd Heinrich is a difficult person to categorize. He is not “best known” for any one thing because he has achieved remarkable distinction in several fields, all interrelated. Some might recognize Heinrich as an ultramarathoner who won the first marathon he ever ran with a time of 2:29:16 on a hilly course in San Francisco, and has gone on to post eye-popping times in other races. He wrote about running from the perspective of an evolutionary biologist in “Why We Run: A Natural History.”

Or, bird lovers may know Heinrich as “the raven guy,” who studied and wrote about his semi-tame birds for years and summed up his observations in several books, including “Mind of the Raven: Investigations and Adventures with Wolf-Birds.”

Professional ecologists esteem Heinrich as the researcher who broke open an entirely new field of study with his doctoral dissertation on how sphinx moths regulate their body temperature high above ambient temps. His thesis blurred the distinction between so-called “warmblooded” and “coldblooded” animals and paved the way for new ideas on how organisms relate to their environments.

Heinrich is professor emeritus at the University of Vermont, out of which he still teaches, yearly, a winter ecology course. He is the author of “Winter World,” “Bumblebee Economics,” and “A Year in the Maine Woods.”

At the heart of these varied interests is this: Heinrich is in love with nature. It is fitting that his 22nd book, produced by the 78-year-old naturalist, is titled “A Naturalist at Large: The Best Essays of Bernd Heinrich.” These 35 essays, which have appeared before in Natural History magazine and elsewhere, are his attempt to show the reader how science, at its foundation, is done. Nearly every essay begins with some observation: a tiger swallowtail caterpillar on a hickory leaf that remains exactly in place day after day, yet gets larger by the day; an ice storm hits and some trees break under the weight of the ice and others do not; tiny golden-crowned kinglets survive severe Maine winters with very high body temperatures. Heinrich’s observations are keen, perceptive and imbued with knowledge gleaned over a lifetime. This is natural history at its finest, how observations are the spring board into investigations into the nature of reality.

He mulls over what he has seen. Things have caught his eye because they are odd, out of place, not what one would expect. Yet, to an evolutionary biologist, nothing is random. Traits and behaviors have functions. What is happening here?

Full immersion

Heinrich is good at devising simple experiments that get at the heart of the question. He rigs up a contraption for his ravens that involves meat dangling from a string, testing whether the birds can solve a problem. He slices open yellow iris buds to ascertain the trigger mechanism that enables them to open in a flash. He captures aquatic whirligig beetles by wielding a dip net, standing in the bow of a canoe, and dots their backs with red paint to track their movement on Lake Itasca.

The conclusions he draws tells him and the reader something new about this wonderful planet. His aim in the winter ecology course that he teaches out of his isolated Maine cabin is to get his students to “stop just reading about nature and also start experiencing it.” Heinrich would claim that far too many of us — biologists included — have little contact with the natural world. It seems most people would agree with writer Fran Lebowitz that “the outdoors is what you must pass through in order to get from your apartment into a taxi cab.” Or what surrounds you while you are looking at a screen.

Heinrich is able to see what he sees and write what he does because he has been immersed in nature since childhood. Born in eastern Germany during World War II, his family fled the oncoming Russian army at the end of the war. His early years were spent in rough lodging in a forest in northern Germany where Heinrich had daily, intimate contact with the woods and its inhabitants. In Maine as a teen, he likewise spent long hours roaming outdoors, watching birds and insects and squirrels live their lives. A Naturalist at Large testifies to his belief that knowing the science behind what’s happening in nature deepens and amplifies the pleasure of being outside with our kin who share the earth with us.

 

Author Sue Leaf lives in Center City, Minn.