SO MANY THINGS I have observed, noted, and sometimes even taken photos of but did not understand have been explained to me in absentia by Bernd Heinrich, who has a special gift for not just science and nature, but also for the written word. The prolific author, professor emeritus of biology, and ultramarathoner is also a man who is most at home in a cabin he built on 600 acres of western Maine forest. I mention the “at home” part because Heinrich’s latest book–-his 18th–is called “The Homing Instinct: Meaning and Mystery in Animal Migration.”
We discussed the subject of home and homing on the May 19, 2014 edition of my public-radio show and podcast; read along while you listen using the player below. You can subscribe to all future editions on iTunes or Stitcher (and browse my archive of podcasts here).
“Basically everything in the life of organisms relates to being in the right place,” says Heinrich, then 74, a thought that wove through the discussion on my latest radio show.
my q&a with bernd heinrich
Q. Your books always seem to come at just the right time for me, thank you very much. I had just read “The Homing Instinct” when the first flicker reappeared early this spring, and made a beeline to the spot near my house where every year a giant anthill eventually forms.
Was it observations like that that made you study the homing instinct?
A. Certainly observations like that make me wonder a lot. And speaking of flickers: I had one make a hole in my cabin and nest there two years ago, and I watched him from up close. In fact I was wondering if the flicker would come back this year, too. Once I heard some scratching—but they haven’t nested in there yet.
Q. How did “The Homing Instinct” come to be, and why did this subject bubble up to the top of the list now for you?
A. The example of the flicker brings up the whole topic of bird migration, which is of course is very central to the homing instinct, to homemaking, migration and navigation. All of these things are extremely interesting to me, because I am a comparative biologist and I study bees a lot, and make comparisons with other animals. So it’s been bubbling up there for quite awhile.
Q. I know you are always working on more than one book, and area of research, at a time—but your last one, “Life Everlasting: The Animal Way of Death” seems like it just came out. Are you always multitasking up there in the woods?
A. Yes, I’m always multitasking. The thing is, the flicker or whatever only comes by once in awhile, so if you’re going to be just watching just one phenomenon, you might be very lucky to see it and then have to wait a long time again.
So at some time I will be very intensively watching one thing and then it’s gone for months or years, and in the meantime I do something else of interest–I’m basically interested in all kinds of things.
I’m usually doing at least three books at the same time.
Q. You write that, “The minute dimensions of some animals’ brains are as astounding as the homing capacity of some of their owners.” What are some of the motivations for “homing”–reasons different animals find their way home at moments in the year, or life cycle?
A. I was looking at a very broad description in the book with regard to homing. It seems like almost everything I was thinking about eventually led back to home, or is related to homing.
When you look at it from a broader, more distant perspective, you can even talk about homing in plants. Basically everything in the life of organisms relates to being in the right place at the right time. All of life depends on that.
The more I was looking into it—it seems like everything is related. In scientific literature, it seemed like it was all fragmented, and split up into different topics, and I just wanted to bring it together to see the totality.
I was even looking at myself, having issues about homing, and returning to where I wanted to be and where I had grown up. I was thinking, well, that’s exactly what birds do, and what many animals do: They remember where they had grown up, where they were born and go back there. It’s a good place; obviously they were successful, so they’re going to go back there.
Q. I think you mention a phoebe in the new book, and every year at my home, for the last 28 years, I’ve watched a phoebe come and nest on the same outdoor light fixture. I know it’s not the same bird—but they keep on doing it.
A. Birds of course learn the nest site, though first of all there are evolutionary results: that they generally choose the right kind of place, the right habitat, and make the right kind of nest.
But there is learning as well with respect to the location.
For example, if the geese in the bog nest on the shore and the coyotes keep raiding them, pretty soon one will nest on a beaver lodge, and they won’t be raided; they will be avoiding the shore. There is experience that goes with it.
A. It depends on what precisely we’re talking about with respect to homing—so for instance, that’s homemaking. I was looking at bees. They have to go out and forage, so when they’re getting food in a sense involves homing mechanisms:
Using the landmarks and the location of the sun, and having a time sense, and being able to interpret the direction from the sun. They have to home in on the location where they have found food, and then they have to home to their real home—their hive—to be able to return.
This is very similar to what we do, too. We’re not very good homers, though we can and do use landmarks, but there are huge gradations of capability, and differences in senses. We don’t have the magnetic sense, for instance. Many birds, we now know, have magnetic sense and can use magnetic orientation to get at least a certain direction and maybe even location.
Turtles do it, and many insects do it. Using the sun as a compass, and landmarks from up close—anything that shows up in the environment. In a sense I suppose using stellar orientation—using the stars as many birds do—is using landmarks, too, using some feature in the environment to orient by.
Of course if the stars are moving that makes it more complex! [Laughter.]
Q. The shifting landscape! [Laughter.]
As a variation on “homing,” something that even casual observers have probably noted is how some insects—such as aphids–aggregate. In the section of the book called “Getting to a Good Place,” you talk about that. Explain.
A. I mention the tent caterpillars—they are in the same place because the eggs were deposited in one place by the female moth, but then when they hatch out, the caterpillars stay in the group for quite awhile, as they are growing up.
Initially, that is apparently so they can make themselves something like a little greenhouse, in the tent, and stay warm in the spring. There’s no wind in there, and the cooling factor is reduced, so that’s where they stay while they’re digesting food. That increases their rate of digestion, and metabolism, and growth, and reduces their vulnerable period as caterpillars. So they stay together and keep making the tent and enlarging it, and they go back and forth to the leaves as they feed.
Q. What about aphids?
A. Aphids multiply in any one place—and so there are nymphs, and adults, and offspring together. But they have to get to green plants to be able to suck the phloem sap, so they have to disperse.
Their powers of flight are so feeble that they can’t really have much choice where they go, however.
It’s quite ingenious what they do. It involves morphology—for example, when it’s time to disperse, they grow wings. And then they dislodge themselves into the air, and drift by the wind or maybe feebly fly and then descend someplace. Chances are some of them will find green [plants]…and then they’re on food again, and can start a new colony. They can even reproduce parthenogenetically—so if you don’t have a mate, you just have virgin births.
So everything is related to getting to a good place, and taking advantage of it.
The stories are very different from one animal to another, but ultimately they all have the same idea behind it.
Q. The ladybird beetles—I live in an old house, and they are always inside at certain times of years [above, in fall], eventually clustered together in the corner of a window, perhaps. Why do they aggregate like that?
A. Generally some of these noxious insects that advertise themselves with bright colors, they educate potential predators. If you are with others, and a bird was around to start picking off the insects, presumably if they tasted a few of them and they tasted really bitter, it’s going to leave the rest alone.
If you were all alone then the bird might give you a shot.
With others, you have safety. A number of insects have that strategy of gathering up into groups—for instance, gyrating beetles on the water surface. They have a very noxious poison if fish try to eat them when they gather together on the water surface. There’s aggregation—they home in on each other, and follow each other.
Q. So I see the world outside my little house through the lens of plants. What are some of the ways that the homing instinct of insects or animals is connected to the success (or failure, maybe) of plants?
A. That’s an interesting question. It’s basically about getting to a good place; the same thing applies to plants. They have to find a place where they can get energy (which in their case is sunlight), and water, and nutrients, and they have to get away from their parents in some cases.
If you’re a big tree you’ll need the light, so you can’t grow under [the parent]—so we’re talking about dispersal; the destination has to be a good one, but it’s not pre-determined. There is a lot of chance involved in getting away. It’s not migration; not about moving in one specific direction.
Some seeds do find that place, though—for instance with plants like poplars or dandelions, whose seeds are blown by the wind. Or we have the mechanical dispersal, such as with burdock or other seeds that stick to fur and can be carried around. Or, in the book, with my chestnut trees—the nuts of which are dispersed by animals. They basically take advantage of being food. Some are sacrificed as food, [in return] for the dispersal. The jays, for example, will hide the nuts away from the source, taking them to a good place.
Q. With the help of the jays or the squirrels, they get there.
Speaking of squirrels and birds, the section called “Home Crashers” in the new book is delightful. (And so familiar; I live with many companions in my old rural home with its stone foundation, too.) Who’s there at the moment?
A. Well, it’s not bedbugs, mites or fleas. [Laughter.] Mice, cluster flies, ladybird beetles…but they’re leaving right now; they only want to stay in the wintertime.
The phoebe you mentioned earlier is a home crasher—but a welcome one; some are more welcome than others. Certainly the flicker, who built a nest in my wall was. I chainsawed out the wall on the other side so I could watch the nest.
Q. Like an ant farm, but for watching birds!
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MY WEEKLY public-radio show, rated a “top-5 garden podcast” by “The Guardian” newspaper in the UK, began its seventh year in March 2016. In 2016, the show won three silver medals for excellence from the Garden Writers Association. It’s produced at Robin Hood Radio, the smallest NPR station in the nation. Listen locally in the Hudson Valley (NY)-Berkshires (MA)-Litchfield Hills (CT) Mondays at 8:30 AM Eastern, rerun at 8:30 Saturdays. You can subscribe to all future editions on iTunes or Stitcher (and browse my archive of podcasts here).
how to win ‘the homing instinct’
I’VE BOUGHT TWO extra copies of “The Homing Instinct: Meaning & Mystery in Animal Migration” to share with you. All you have to do to enter is answer this question in the comments box provided at the very bottom of the page–below the last comment:
Is there an example of “homing” that you want to share–perhaps one that you look forward to each year,
I mark the spring return of each bird species, and am also especially fascinated by amphibian movements: the rainy, warmish early “big nights” when salamanders and others move to their breeding grounds, usually in April around here.
No answer, or feeling shy? Just say, “Count me in,” or something of that sort, and I will, but I hope you’ll tell me some example you have observed or wonder about.
Two winners will be chosen at random after entries close at midnight Monday, May 26. (U.S. and Canada winners only. ) Good luck to all.
(Author photo copyright Kyle Isherwood. Disclosure: Purchases via Amazon affiliate links yield a small commission that I use to buy prizes for future giveaways.)