THE SPRING MIGRATION is on, so birds and their travels were the subject of my recent conversation with Kenn Kaufman, author of the recent book, “A Season on the Wind: Inside the World of Spring Migration.”

Kenn, originator of the indispensable Kaufman Field Guide series, is one of the world’s leading naturalists and experts on birds. His lifelong interest in them began at age 6. He and his wife, Kimberly, director of the Black Swamp Bird Observatory, live on the west end of Lake Erie, where spring brings millions of birds virtually to their doorstep, including many warblers (that’s his photo of a bay-breasted warbler, top of page).

We discussed what triggers birds to move—and why some go long distances versus shorter ones, or choose to fly by day or instead by night.  Kenn encourages us to track signs of the migration right in our own backyards, and offers other encouragement.

We talked about a theme in the new book that isn’t so upbeat: How one form of renewable energy, wind turbines, pose a substantial hazard to birds when placed in their concentration points—such as where migrating birds stop over during their long journeys.

And about how despite all these years of watching migrations, Kenn still feels awe.

I’ll give away a copy of the book to one lucky reader—enter in the comments box at the bottom of the page.

Read along as you listen to the May 6, 2019 edition of my public-radio show and podcast using the player below. You can subscribe to all future editions on iTunes or Spotify or Stitcher (and browse my archive of podcasts here).

bird migration, with kenn kaufman

Margaret: Congratulations on the new book, “A Season on the Wind: Inside the World of Spring Migration.” One of your earlier books is one of my favorite books, “Kingbird Highway,” when you take us-

Kenn: Well, thank you.

Margaret: You take us hither and yon as you detail your own migrations in a given year of your youth, hitchhiking around in pursuit of birds. Now, in this new book, you sort of stay put. Do you know what I mean? It’s about bird migration, but it takes place mostly in this birding mecca in Ohio near where you live, doesn’t it?

Kenn: Yes, it does. In the past, I had traveled all over the continent and really all over the world to visit places where there were spectacles of migration. But I didn’t really start to gain a deeper understanding of it until I spent some time just staying at home and watching what was happening in one place. That was what turned into the focus for the book.

Margaret: Is there a master plan to springtime bird movement? Do birds fall into some major categories of behavior having to do with their movements in spring, like how far they move or don’t move, and so forth? Are there categories that we can understand as laypeople?

Kenn: There are some broad divisions and a complete range of birds, from those that are totally sedentary to those that travel long distances. There are hardly any birds that just really stay put completely for their whole lives, even birds that we think of as residents, like cardinals, will move around to some extent within a local area.

Then, you have your short-distance migrants that are present, that don’t have totally separate areas on the rangeland. They may get a little farther north in summer and a little farther south in winter. Then, the moderate-distance migrants that may go from, say, Central Canada to the Southern United States for the winter. And then very long-distance migrants that may go from Alaska to Brazil or Argentina, just these astounding long-distance migrations. But, really there’s every stage in between.

Margaret: The ones that go those very long distances, it’s not optional. They have to do that, yes? I think in the book maybe you call it hard-wired, yes? They’re hardwired to have to do that, whereas some of the ones that can move a little, they don’t have to move quite as far. They can move a couple hundred miles or something?

Kenn: Yes, that’s exactly right. The long-distance ones, the hard-wired ones, they’re sometimes called obligate migrants, and then the others that can be more flexible will be called facultative migrants. Most of the latter are the short-distance travelers.

An example would be something like the kildeer [below, in flight], which live out in the open field here. Where I am in Northern Ohio, the last kildeers of the fall disappear sometime in early to mid-December, then the first ones come back in February, so it hardly seems worth the trouble [laughter.]. They may only go as far as the southern part of the state before they turn around and come back.

They can vary their timing and their distance, and they may travel … They may come north earlier in a warmer spring. So, they’ve got the flexibility that most birds don’t. [Kildeer photo by CheepShot from Wikipedia.]

Margaret: Right. What are the triggers that say to birds, “Time to move!” Is it just “follow the food”–is it that simple?  Or I think there’s … One of the chapters in the new book is called “Creatures of Light.” I think it talks about some triggers having to do with our response as animals, ours and theirs [laughter], to light and so forth. What are the triggers that say, “It’s time”?

Kenn: The ones that we know something about, a lot of them have to do with the length of the daylight, and the birds are really attuned to the timing of sunrise and sunset. As they change with the seasons, the birds will start to move.

It would make sense to think they’re just following the availability of food, but, actually, in fall, a lot of birds will fly south and fly away from habitats that are full of food. They leave before the cold weather arrives, and the timing is set by the change in light levels.

There will be some places near the equator where that wouldn’t work, and where they may be driven more by changes from wet season to dry season. But in North America, the length of the daylight really seems to be the driving factor.

Margaret: Interesting. Living in a rural place, I notice that about so many animals. They seem to know … I shouldn’t anthropomorphize but I will, anyway. [Laughter.] I’ll use words like “seem to know.” Things change: the sounds in the morning. I was just talking about this with some birding friends yesterday. There’s that moment in later summer where the dawn chorus—the whole sound changes.

And you see other kinds of animals doing activities, like you see more hoarding behavior among some animals that are going to hibernate or semi-hibernate. The activities and the patterns change at a moment, and it can’t be that everybody looked at their calendar, do you know what I mean–and said, “Oh, it’s the day we’re supposed to do this.” It must be the trigger of light, yes, of daylength?

Kenn: Yes. I think it has to be. I really do think that humans can become attuned to the regime of light in the area where they live.

Margaret: You talked about that in the book, about you were kind of disoriented. You moved to Ohio, I don’t remember how many years ago, from a different region, yes?

Kenn: Yes, in 2005, I moved from Arizona to Ohio, and I noticed almost immediately that it was different there [laughter]. Including the light levels and so I was sort of disoriented for a couple of years until I gradually became attuned to it.

Margaret: Speaking of light, does migration mostly take place in darkness, at night, or are there some birds who move during the daylight hours?

Kenn: That’s one of the fascinating things about it, and one of the things that makes it hard to study is that there are quite a few species of larger birds that do migrate in daylight. Most of the hawks, for example, are daytime fliers. Cranes mostly migrate by day. Ducks and geese may migrate by day or by night.

But most of the smaller birds, most of the songbirds, which are, of course, the most abundant ones, migrate at night. So, they’ll take off just after it gets dark and fly through the night, and then, if they’re over land, they’ll come down around dawn and … Of course, this makes it hard to study what’s going on up there.

Margaret: Do we have an idea of why we think that’s the case? Are they navigating—celestial navigation—or is it because it’s cooler at night? Is there a reason that we think?

Kenn: There’s been a lot of ideas tossed around for why they’re migrating at night. The air masses may be a little more stable then. There may be fewer predators flying around. The hawks are migrating in the daytime [laughter], so nighttime-

Margaret: So, if you’re a songbird [laughter]...

Kenn: Yes, makes a difference.

Margaret: I see. Yes.

Kenn: They do use navigation by the stars, although daytime migrants can navigate by the sun as well.

Margaret: Yes. I remember years ago hearing about “flyways,” these … As I visualized it from being told or reading about it years ago, the highways or corridors ins the sky that I imagined that birds travel during migration. But that’s not the way it’s understood now, is it?

Kenn: You’re right. The idea of flyways was first developed in the 1930s, when people first started getting lots of returns of banding studies of ducks. Ducks, to some extent, do follow sort of defined pathways because they have to move between specific water areas. So, you’ll have, even though they cross and they go in all different directions, you will have some major routes of travel for the ducks.

A guy named Frederick Lincoln named these flyways back in the 1930s as Atlantic, Mississippi, Central, and Pacific flyways, but, as it turns out, most birds don’t follow those. They don’t concentrate… [Laughter.] Half the birds haven’t read the book.

Margaret: Exactly. [Laughter.]

Kenn: They don’t concentrate in specific pathways. They spread out as much as they can. They only concentrate where they’re forced to by geography. If you could, especially if these nocturnal migrants … If you could look down at North America in early May, a night of peak migration, you wouldn’t see rivers of birds flowing toward the north. Instead, it would look like a blanket of birds being pulled northward, stretching all the way across the continent, and with no real gaps except perhaps going around major mountain ranges or going around storms, that sort of thing.

Margaret: So, strategic differences, things to avoid, etc., and you talk in the book about some, like the raptors, which you were mentioning before, they use the thermals. I don’t even understand exactly what they do, but how do thermals work and what birds take advantage of them? That’s another word that I think people like myself have heard, like we’ve heard about flyways, we’ve heard about thermals. What are thermals?

Kenn: A thermal is just a bubble or column of rising air that’s been heated by sunlight hitting the land or something, so warm air rises in a particular spot. Birds of prey, in particular, will take advantage of those. They’ll find this rising air and just spiral up into the sky. Then, they get to the upper part of the thermal, where it’s becoming weaker, and they’ll peel off and go gliding in the direction they want to go until they come to another thermal and then rise again. They can go for miles without flapping their wings.

Margaret: That’s efficient. If you’re going to go a period of time without eating, maybe, you need to conserve energy. Is that a strategic thing then?

Kenn: Yes, exactly. For the birds of prey, it can be a challenge to … Smaller birds may be eating all day, but for a hawk, it’s a challenge to find prey when you’re traveling. To the extent that they can save energy, they do.

Margaret: We humans learn more about migration lately, partly thanks to advances in technology, tracking devices, and radar, whatever.  You give an example in the book of this “champion thrush” that was tagged with a device and then observed to fly non-stop, I think, across the Caribbean and all the way to Canada. Again, non-stop, pretty amazing.

In sharing that anecdote, you then write, “I love science, and I hate it.” Then, you say, “In a way, we know more about the birds’ travels than they do.” Tell me a little bit about that part of the story for you. [Above, depiction of migration patterns of two warblers, from Cornell research.]

Kenn: Well, I was opening up there and admitting the ambivalence I have about this. I’ve spent so much time reading scientific and technical works [laughter], dozens of technical volumes and hundreds of scientific papers, to try to understand the science of it. But, I don’t ever want to lose sight of the fact that we’re witnessing something here that’s just … It’s magical. It’s a miracle, and it should be just a total source of wonder.

I find that the more facts that I learn about the migration of birds, actually the more wonderful it becomes. Knowing more about how they do it doesn’t make me any less impressed with the fact that it happens at all. I really feel like it’s this massive, worldwide miracle that happens twice a year, and I hope I’ll never get over the sense of wonder at it.

It just seems sad when sometimes people will take something and make a very scientific analysis of it and try to be dry and formal and technical, because they feel like they have to do that to be scientific. I think the best scientists I’ve met have never lost their sense of wonder, almost a childlike-

Margaret: Yes, awe.

Kenn: … amazement and wonder at what we see out there.

Margaret: Speaking of facts, one in the book that comes back—sort of this riff that goes through the book, and it’s not such a happy fact—but it’s the fact that we humans, in trying with the theoretical goal being to develop types of energy that are more green, that we may be causing havoc and harming birds by some of our tactics. I wondered if you could talk a little bit about how that knowledge came to you with the wind turbines and so forth. [Billboard, above, from Black Swamp Bird Observatory.]

Kenn: O.K. Everyone I know who really pays close attention to birds has realized that the climate is changing, the climate is overall becoming warmer, and weather is becoming more extreme. We recognize that climate change is a real thing that has to be addressed. I don’t know anyone who’s opposed to green energy or renewable energy, but there are some places where we have to be careful about what we put up.

Wind energy can be really effective in some places, but a tall tower with spinning blades understandably can be bad for things that fly around in the sky. So, it’s a paradox that we’re not opposed to wind energy, but we think that location is extremely important.

Margaret: Yes.

Kenn: Certain types of places are such concentration points for birds that wind power really doesn’t belong there. One example would be stopover habitat for these migratory birds. The area where I live in northwestern Ohio, birds that are migrating across the continent come down before they come to the edge of Lake Erie, and so we get massive concentrations of birds stopping over there feeding, resting, getting ready for their next flight.

These nocturnal migrants are arriving at the dim light just before dawn. They’re coming down and landing in this half-light before dawn. They’re taking off just after it gets dark at night. So, the times of day when the visibility is worse, they would be flying through the part of the air column that would be swept by the rotors of wind turbines. We feel that the wind power should be kept out of these critical stopover habitats for birds.

Margaret: It seems so obvious, and yet the struggle that you depict in the book, and probably others that have been happening in other areas, that you talk about in your area that you and your wife and others have sought to change, to get that kind of a project out of that type of habitat, it’s pretty shocking. Again, it seems obvious that we should avoid this and yet, we’re not avoiding this.

Kenn: It should be. [Laughter.] It should be obvious, shouldn’t it?

Margaret: Yes.

Kenn: Wind turbines, we should not put them up at the end of a runway at a major airport. That’s not a good place for them.

Margaret: Yes, yes, yes. It’s the time: It’s migration. It’s spring, and you’ve been watching migrations for a long time, and you’re an expert at this, an expert observer. I noted that, I think it was the Audubon website where you’re a contributor, they did an excerpt from the book. I think the headline was something like, “The Backyard is One of the Best Spots to Witness Bird Migration.” [Laughter.] Is our backyard the place we should become a more astute observer of migration.  Tell us a little bit … Invite us to the places we should go or what kinds of places we should go.

Kenn: I really feel like the backyard is the best place to look. I know not everyone even has a yard, but any local park, any little area of garden or public gardens or semi-natural habitat is a place to observe bird migration because it is happening on a broad front. Well, I was going to say, you don’t have to live on a flyway, but we all live on a flyway.

Margaret: Right.

Kenn: We’re all there. [Laughter.] So, just getting out every day and just looking around to see what happens. Migrating birds will come through. In the book, I talk about … Yes, I live in a place that’s great for migration, but a lot of the book focuses on things like robins and red-winged blackbirds and common birds, song sparrows—how they respond to the arrival of spring. Staying in one place and watching the season unfold, I think, is the best way to learn about it.

Margaret: Yes. I find inspiration and validation maybe also in participating in … and, I don’t do it in a major way, but I do it a couple of times each week … in a citizen science kind of a thing like eBird.org, of recording my sightings: the first day that the male rose-breasted grosbeak showed up for this spring in my yard last week, and who’s around each day. Today was an Eastern wood-pewee, and so on and so forth. I love going there and seeing, exploring in the “Explore” area, seeing in my county that someone else saw a similar bird a day or two before. It’s that sense that it’s happening in a bigger way even though I’m only in my backyard looking out the window. Do you know what I mean?

Kenn: That’s a wonderful way to take part in it. I’m addicted to eBird and bird sightings there.

Margaret: [Laughter.]

Kenn: I just love the way it reveals things like there were three red-breasted nuthatches out in the yard the other day. It could have been just a fluke, but I went to eBird and starting looking around, and there were red-breasted nuthatches passing through all over the area at the same time. It puts our own sightings in context, a wonderful thing to do. [Red-breasted nuthatch, above; photo from Wikipedia by Walter Siegmund.]

Margaret: Yes, yes. Well, I love the book, “A Season on the Wind: Inside the World of Spring Migration,” Kenn. Are you writing something else now or are you taking a little bit of a break?

Kenn: [Laughter.] Well, yes, I think I’m going to be continuing to work on books probably for the rest of my life.

Margaret: Yes, I can’t help it, either. [Laughter.]

Kenn: I’m very much enjoying the brand new edition of your book.

Margaret: Oh, good!

Kenn: “A Way to Garden.” It’s just wonderful.

Margaret: Oh, good!

Kenn: I love your prose style.

Margaret: Oh, well, that’s very sweet. That’s a high compliment because I’ve been, as I said, reading your books for a long time, both the literary ones, the ones like this, and also the field guides that you founded—that group of field guides. I have many of them on my shelf next to where I work all day, and am always looking things up, so thank you so much for this and for those.

Kenn: I’ll send you a note once I get close enough to having another one ready to come out.

more from kenn kaufman

• Kenn’s columns on Audubon’s website
• Kenn’s Instagram, with a sampling of his wildlife paintings
• All Kenn’s books on Amazon
• My older piece about his “Kingbird Highway,” a vintage extreme birding tale (above{ that I enjoyed

enter to win ”a season on the wind’

I’LL BUY A COPY of the book “A Season on the Wind: Inside the World of Spring Migration” for one lucky reader. All you have to do to enter is comment in the box at the very bottom of this page, answering this question:

Tell us about your migration connections so far this spring. Have you seen any “new” birds already, in your own backyard or maybe elsewhere that you have visited? Did you enter them into eBird.org?

No answer, or feeling shy? Just say something like “count me in,” and I will, but an answer’s even better. I’ll pick a random winner after entries end at midnight Tuesday, May 14. Good luck to all.

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MY WEEKLY public-radio show, rated a “top-5 garden podcast” by “The Guardian” newspaper in the UK, began its 10th year in March 2019. 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. Or play the May 6, 2019 show using the player near the top of this transcript. You can subscribe to all future editions on iTunes/Apple Podcasts or Spotify
or Stitcher (and browse my archive of podcasts here).