You can go home again

The Swainson’s thrush uses the stars and the magnetic field to navigate during migration. Photo by Jeff Nadler
The Swainson’s thrush uses the stars and the magnetic field to navigate during migration.
Photo by Jeff Nadler

MY FIRST MEETING with the nature writer Bernd Heinrich came on a dark, stormy night at the Saranac Lake Free Library. He was reading from a book then in progress, The Snoring Bird, which combines a biography of the author’s entomologist father with Bernd Heinrich’s own life story.

Anyone who had the privilege of being in attendance that night will remember the tumultuous weather outside, the gasps for breath, and the tears that ran in rivulets down Heinrich’s face as he spoke about his relationship with a brilliant but ruthless father. The audience glimpsed the intensity and passion that drive Heinrich’s work as a biologist working in the field of experimental physiology. It’s the same kind of feelings that make his books—about ravens, owls, bumblebees, golden-crowned kinglets, trees, and more—compelling to read.

Heinrich’s newest, The Homing Instinct: Meaning and Mystery in Animal Migration, follows in the vein of his recent works Life Everlasting (2013) and The Nesting Season: Cuckoos, Cuckolds, and the Invention of Monogamy (2011). Like these books, it’s a work of synthesis, of bringing together. It builds on Heinrich’s own investigations into home-based animal behaviors while sifting the scientific literature for additional insights into how and why animals establish and return to nests, dens, and breeding places.

Heinrich is a biologist who places his own species squarely in the natural world. From him, we also gain ideas about our own devotion to home.

The author began writing The Homing Instinct after a distinguished teaching career at the University of Vermont and the University of California at Berkeley. He had returned to his childhood home in Maine and there found himself in the midst of what we today call “issues.” “Because I had written a book about my father, and not also one about my sisters or my mother,” he explains, “I had come into the disfavor of both. … It seemed like being in a real-life situation of the sociobiology theories, in an almost perfect rendition of a naked mole rat colony, where one of the family finds a big tuber, and the others claim it as theirs, and then a highly vocally assertive member establishes herself as the matriarch.”

Heinrich’s extended family failed to appreciate the mole-rat analogy, I suspect. Yet for the rest of us, the point is well-taken. Human behaviors, the good, the bad, and the ugly, have much in common with those of other animals. Insights into one often yield useful clues to help comprehend the other.

Adirondack readers will find much to engage them in The Homing Instinct. Heinrich, quoting freely from scientific papers while also drawing from the works of James Fenimore Cooper and John Burroughs, shines light on the lives of creatures we encounter during our walks and boat trips in the Park. For example, loons, we learn, come to their summer homes on our lakes not only as mated pairs but as “floaters.” The floaters are unmated males, often two or three years of age. Floaters sometimes challenge breeding males. On occasion floaters may fight them to the death.

One of Heinrich’s gifts to the reader is to bring us in on the detective work that leads to scientific conclusions. In one particularly compelling section, he follows the work of German scientists shuffling hives and sugar sources and using high-tech monitoring equipment, all to try to work out how honeybees discover and share nectar and pollen. It’s the kind of material few of us would have the time, opportunity, or inclination to ferret out of technical journals. However, when a science writer like Heinrich comes along to gather it and translate it into language that’s inviting, we gobble up every morsel.

Tent caterpillars, monarch butterflies, and painted ladies abound in the Adirondacks. There are fresh perspectives on their lives here. American eels, which swim and feed in Adirondack lakes and ponds, surface in the book, too. Heinrich recounts how researchers slowly and methodically, over many years, pieced together the story of the eel’s reproduction. American eel males remain in salt water year-round, we now know. Females grow to maturity in fresh water, then descend creeks and rivers to the sea to mate.

The homing of migratory birds over vast distances was long a mystery crying out for understanding. Heinrich provides a summary of work on the topic. We learn, for example, of landmark studies by ornithologist Stephen Emlen at Cornell. Emlen’s experiments with captive-raised indigo bunting nestlings proved, as biologists had theorized, that the birds could learn and orient to star patterns and that when these star patterns are altered in a planetarium, the young birds orient to the manipulated sky. More recent work is described, too. We learn, as scientists have only in the past decade or so, that Savannah sparrows, gray-cheeked thrushes, and Swainson’s thrushes (all birds we see routinely in the Adirondacks) use not only stars to navigate to breeding grounds but also polarized light and the orientation of the earth’s magnetic field.

The Homing Instinct Meaning and Mystery in Animal Migration By Bernd Heinrich Houghton Mifflin Harcourt, 2014 Hardcover, 384 pages, $27
The Homing Instinct
Meaning and Mystery
in Animal Migration
By Bernd Heinrich
Houghton Mifflin Harcourt, 2014
Hardcover, 384 pages, $27

In Heinrich’s hands, as in real life, science is detective work conducted by sleuths who sift through clues and devise experiments to test their latest notions. Heinrich is frank with the reader about the often stark divide between what we’ve learned and what still remains unknown. For example, regarding the compasses that have been demonstrated to function within the brains of pigeons, Catharus thrushes (a group that includes our Adirondack Bicknell’s, Swainson’s, and hermit thrushes), and Savannah sparrows, he writes:

The physiology of how the magnetic sensing works is still a mystery. Possibly iron-containing minerals align like a compass and cause mechanical deflection that is sensed. Presumably the cells or something in the cells swivels like iron filings do in response to a magnet. … Evidence is mounting that some birds can sense magnetic information optically … [and that they can] ‘see’ magnetic lines of force.

Heinrich helps us see that birds view the world in ways that until recently scientists could address only by speculating. In doing so, he helps us see the world in fresh and provocative ways.

The Homing Instinct ends on a cautionary note. Heinrich observes that as “people [are] interconnected by ever more electronics, we are becoming increasingly more oriented to each other. We are attaching to and becoming emotionally linked to social, political, religious, economic, industrial, educational and other social functions, as opposed to the mountains, the prairies, the forests … —all are the ties that had bound us to our planet, but always before locally, to a home.”

Nevertheless, he finds hope. It lies, he suggests, in the human capacity to understand and change, to come to our senses before it’s too late, to save ourselves and our dear old home in the galaxy