TERRY GROSS, HOST:
This is FRESH AIR. I'm Terry Gross.
(SOUNDBITE OF BIRDSONG)
GROSS: That's the sound of the sharp-tailed grouse. We're going to hear some remarkable bird songs and talk about some of the other remarkable abilities birds possess. I have two guests. Gerrit Vyn goes to extremes to photograph birds and record their songs. He says he focuses on birds because they're powerful and visible indicators of environmental health and change. He shot the photographs for the new book, "The Living Bird," which is a production of the Cornell Lab of Ornithology. Vyn is a producer for the lab and has contributed to National Geographic and Audubon. Scott Weidensaul wrote a couple of essays in "The Living Bird." Right now, he's in the process of banding baby owls, that is attaching a lightweight bracelet around the leg of an owl so that the bird's migratory journey can be tracked. He co-directs Project Owlnet, a collaborative effort among research stations across North America studying owl migration. He's also the author of the new book "The Peterson Reference Guide To Owls Of North America And The Caribbean." Let's start with the sounds of two caterwauling barred owls recorded by Gerrit Vyn.
(SOUNDBITE OF BIRDSONG)
GROSS: Oh, that is so fabulous (laughter). Gerrit Vyn, Scott Weidensaul, welcome to FRESH AIR. Gerrit, you recorded the sound that we just heard, so tell us more about what we just heard.
GERRIT VYN: Yep, that was recorded down in a dark moonless night in a bayou in Arkansas, and it's a pair of barred owls. Barred owls are a widespread owl species in North America. And what you hear there is a pair of owls that are pretty worked up because there's another pair of owls nearby, and they're exclaiming their territory with these caterwauling calls. And you can hear a faint call of a young owl in the background.
GROSS: I thought owls were just supposed to hoot. That sounds like nothing like a hoot.
VYN: (Laughter) Well, there are a tremendous diversity of calls that owls make, actually, all sorts of different calls.
GROSS: Did this call succeed in keeping the other owls away?
VYN: Usually, the owls work it out pretty well, but sometimes you'll see them chasing each other and some other things like that. In this particular area in the White River in Arkansas, these owls live at a extremely high density because there's so much good prey there. So there's a lot of jostling of territories that are right adjacent to each other. So there is some interaction between the owls as well, where they're chasing each other. You'll also hear them sometimes landing near other owls and kind of banging the branches with their wings, just making their presence known, but I think physical altercations are more rare.
GROSS: The quality of that sound recording is superb. How did you mic the owls?
VYN: Well, this was near a nest, so I knew the owls were there, the parents were there. And they vocalized pretty frequently through the night. So this was recorded with a stereo microphone set up to - extremely nice, expensive microphones recording in MS stereo, so you really capture that whole feeling of being there when you listen to it.
GROSS: And you set up the mics near the nest.
VYN: A hundred feet from the nest kind of thing - not right near the nest but somewhere where the owls will predictably be and be vocalizing.
GROSS: Now, Scott, you have a new book about owls, "The Peterson Reference Guide To Owls of North America And The Caribbean." What do you love about owls?
SCOTT WEIDENSAUL: I mean, owls are incredibly vocal. And you're right. You know, most owls don't hoot. They make just this ridiculous array of sounds - caterwauling, you know. One of the owls that I studied, a little northern saw-whet owl, sounds like a garbage truck backing up, this mechanical tooting sound. Barn owls, which live in old church steeples and barns and silos, sound like demons spawned from the pit of hell. It's just this horrible, screeching banshee wail that will make you believe in ghosts. They're nocturnal. They're mysterious. We know very little about them. They look vaguely humanlike. They've got these big, round heads and forward facing eyes. So, I mean, people have been fascinated by owls for as long as we've been human. In fact, if you go back 30,000 years ago, on the walls of the Chauvet Cave in France, along with these beautiful murals of cave lions and wooly rhinoceroses, somebody took their finger and inscribed a very clear outline of a little scops owl with its little ear tufts in mud on the wall of the cave. We've loved owls for as long as we've been standing upright as people.
GROSS: I happen to know that you're pretty good at bird calls. You just mentioned some very interesting owl bird calls. Can you do any of them?
WEIDENSAUL: I am terrible at bird calls (laughter) actually. And this is a persistent myth that birders go around imitating bird calls all the time. And the fact of the matter is we have smartphones and iPods like everybody else if we want to play them. We just - you know, Gerrit's recording these amazing things, and you can download them in MP3. But, you know, it's funny. Barred owls are one of those calls that most birders learn to do because it's sort of - when they're just calling back and forth, it sounds like they're saying, who cooks for you? Who cooks for you all? And this is kind of weird, but if you're going to make me imitate one, it would be the northern saw-whet owl because it just sounds like (whistling). And it goes on like that for hours, and it's a psychosis-inducing sound.
WEIDENSAUL: And in the fall, when we're banding them this time of the year, we're studying their migration by catching them and by playing that call at 110 decibels, so that as they're flying over, they hear it and they fly down and investigate. And we've just, you know - we're spending hours in the woods hearing this thing kind of throbbing in our ears. After a while, you start to hear, you know - you start to hear voices. I mean, it really does weird things to you.
GROSS: Well, this reminds me you had a project called Project Owlnet, and it's a collaborative effort among research stations across North America studying owl migration. So what you do - what this project does, I should say - is band the owls so you can trace their migratory patterns. What's in the band?
WEIDENSAUL: Well, there's nothing in the band. It's just a standard leg band that...
GROSS: Oh, there's no, like, GPS on it or anything?
WEIDENSAUL: No, no no. Now, we've used GPS on some bigger owls. We've used little, tiny nanotags on saw-whets and geolocators and things. But no, it's just a - it's a numbered leg band. And it has a unique serial number on it. It's put on. It's loose on the owl's leg, like a bracelet is on a person, stays on for the rest of their life. And Project Owlnet is this collaboration of about of 125 banding stations across North America. And so, you know, I'm - we're working at our sites here in the mountains of eastern Pennsylvania catching owls that were banded in Ontario or Maine or Quebec. And the birds we're banding are picked up, you know, months or years later. And you start stitching all of those little recoveries together, and you start to build a pattern of where these birds are going because, you know, on a sunny, windy day in autumn, you can climb up to the top of the mountains in the Appalachians with a pair of binoculars and count the hawks and eagles and falcons as they fly by. That does not work well at 2 o'clock in the morning on a dark night trying to figure out owl migration. So you have to infer the migration by catching these birds, by banding them. It's a slow process, but, you know, it's really shed a lot of light on what has traditionally been one of the most least known groups of birds in North America.
GROSS: Share with us one incredibly interesting thing you've learned through these tags about owl migration.
WEIDENSAUL: Well, just the fact that there's a lot of them. I mean, when we started working with northern saw-whet owls in the mid-1990s, they were chosen as the symbol for Pennsylvania's Wild Resource Conservation Fund because they're so rare. Nobody ever saw them. Three years ago, in one fall, we caught almost 4,000 of them. I mean, these birds are both incredibly common, but they're very secretive. And they're flying at night. And saw-whet owls are found all across North America. They breed across the northern forests and down through the Rockies and the Appalachians. But in the fall, they migrate almost everywhere. So almost wherever anybody is listening to this interview, at night in the fall there are probably these little owls about the size of a soda can that weigh as much as a robin flying over their house. And we're completely oblivious to it.
GROSS: Let's talk about the spoon-billed sand piper. Let's hear the call, and then we'll talk about why the bird is endangered. But tell us what we're about to hear. What should we be listening for?
VYN: Well, this is a male actually sitting on a nest. And you'll hear the male sort of giving some little contact calls talking to the chicks that have just hatched hours before and are beginning to start wandering around the nest bowl because they do go out and start feeding themselves almost instantly after they hatch.
GROSS: OK. Let's listen.
(SOUNDBITE OF BIRDSONG)
GROSS: So that's the spoon-billed sandpiper and chicks in their nest recorded by Gerrit Vyn. And Gerrit, I just can't believe the quality of the sound that you get. It's really remarkable. Why are these birds endangered?
VYN: Well, we just learned they were endangered in recent years. This is a bird that nests along the coast of Chukotka in Russia. And they winter in Southeast Asia, primarily now in Myanmar but in other places as well. They have one place that is absolutely critical to them making this north-to-south migration every year, and that's the Yellow Sea, you know, the sea that's bordered on one side by China, the other side by the Koreas. And development in that part of the world is happening at a pace that's almost impossible to comprehend. I've gone to the Yellow Sea three times now to film birds there, and you can't even describe to someone the scale of environmental destruction that goes on around the shores of the Yellow Sea. They have a process they call reclamation, where they basically start building seawalls out into their intertidal areas. Now, these are the mudflats that are exposed at low tide that these shorebirds feed on. And they basically built seawalls farther and farther out into the mud and then use that land for other purposes. And more than 60, 70 percent of the entire coastline of Korea and China have been converted in this way. So the spoon-billed sandpiper and, for that matter, an entire flyway of birds, you know, that migrate from Russia and parts of Alaska all the way to New Zealand and Australia, is under deep threat because of this process of reclaiming mudflats and turning them into land.
WEIDENSAUL: One of the species that's using the Yellow Sea that Gerrit's talking about that's been so endangered is the bar-tailed godwit, which is a bird that breeds in Western Alaska that has the longest nonstop migration of any bird in the world that we know of - 'cause we keep discovering more things that birds are able to do. But this is a bird that takes off from Alaska, flies 7,200 miles nonstop across the widest part of the Pacific Ocean. It takes it between seven and nine days of continuous, non-stop, powered flight. I mean, these birds are flying at the same rate - metabolic rate - of a human running four-minute miles. So imagine running four-minute miles for nine days with no food, water or rest. And in order to do this, before they leave Alaska, they spend two weeks gorging on food. They double their weight, so they're more than 50 percent fat by the time they're ready to leave. They feel like water balloons when you pick them up. And to save weight after they've gained all of that fat, their digestive organs atrophy within a matter of a couple of days. So their intestines and their liver and their kidneys shrink down dramatically at the same time that their breast muscles, which power their, flight increase by 30 to 50 percent in mass. And their heart muscle increases by 50 percent in mass. So they get ripped and buff with no exercise after binge feeding for two weeks. They make this incredible flight to New Zealand and Australia. They land, regrow their guts, spend the austral summer down there, and then make this flight, you know - 'cause they can't fly back the way they came across the Pacific 'cause they'd be fighting headwinds the whole way. So they go from New Zealand to the Yellow Sea, same thing happens. They land. They gorge. Their guts shrink. They fly from there back to Alaska. It's an 18,000 mile roundtrip that these birds will do every year for 25 or 30 years. And if that one place on the Yellow Sea in China and the Koreas disappears, that whole migratory system falls apart - and not just for this one species but for the spoon-billed sandpiper and dozens of other austral-Asian migrant shorebirds.
GROSS: Well, there's lots more to talk about about how remarkable birds are, but first we have to take a short break. So let me reintroduce you both. My guests are Gerrit Vyn, a photographer with the Cornell Lab of Ornithology, and he did all the amazing photographs for the new book, "The Living Bird." Also with us is Scott Weidensaul, who writes about birds and has studied birds for years, particularly bird migration. He contributed essays to this new book, and he also has a new book of his own called, "The Peterson Reference Guide To Owls Of North America And The Carribean." Let's take a short break, and then it's back to hearing more birds and talking about them. This is FRESH AIR.
GROSS: If you're just joining us, we're talking about birds with two people who are affiliated with the Cornell Lab of Ornithology. My guest Gerrit Vyn is the photographer for the new book "The Living Bird" that the Cornell Lab put together. And my other guest, Scott Weidensaul, contributed a couple of essays to this book and also has a new book, a Peterson Guide to Owls of North America and the Caribbean. You've both studied a lot of raptors, but there's also birds that the raptors feed on as prey. In fact, let's hear the song of one of those birds that raptors feed on. And this is the red knot. Gerrit, you recorded this bird's song. Would you tell us something about what we're about to hear?
VYN: Sure, so the red knot is a shorebird species. And for people that aren't familiar with birds, they may be familiar with one shorebird called a Sanderling, and that's the little bird that you see chasing waves back and forth on the beach. Well, there's dozens of shorebird species, most of them - many of them nest in the High Arctic and undergo long-distance immigrations to South America or Southern United States or, you know, various southern places. But this particular species, the red knot, nests way high in the Canadian High Arctic and in places in Russia and in Alaska. And they migrate to different places, but the East Coast population from the Canadian Arctic actually goes all the way down to Tierra del Fuego. So these birds undergo these tremendous migrations. And when they're migrating, people always see them in flocks. And they're in winter plumage and kind of dull, and they're quiet. But when they get up on the tundra to nest, they become these very territorial, independent birds. And they get together in pairs. And males of most of these species perform these elaborate display flights accompanied by some of the most beautiful bird vocalizations you'll ever hear. And this bird, the red knot, which I recorded actually in Chukotka in Russia a couple of years back, is doing one of these display flights. And to me, this is one of the most beautiful sounds that I've ever heard in the Arctic, hearing this haunting kind of melancholy call of the red knot over the tundra.
GROSS: Let's hear it.
(SOUNDBITE OF RED KNOT CALL)
GROSS: So that's a red knot recorded by our guest, Gerrit Vyn. And it sounds - this is so projecting human values onto the bird call - it almost sounds like an alarm.
VYN: Yeah, it really does. It's a...
GROSS: Or a siren.
VYN: Yeah, and, you know, it's funny you say that because alarms and sirens are these repetitive sounds that carry over distance. And they keep playing so eventually you'll hear them, even if it's in a loud, noisy environment. And many of these birds that live in areas where there are no trees do these display flights in the air, and many of them live in very windy environments like the Arctic or the Great Plains grasslands. And so many of them do have these kind of repeated calls. So if you're listening from a far distance, eventually, as the wind dies and ebbs and flows, you'll hear that call. So they transmit over a long distance when they repeat them like that over and over.
GROSS: It's interesting that the song is meant to carry far distances, but in terms of their feathers - their feathers are meant to camouflage them. So they're both...
GROSS: Have these, like, penetrating sounds but this camouflaged look to hide.
VYN: Yeah, when they're in the air and they're calling, they want all the other male red knots in the area to know, this is my territory; stay away. And down below, he knows he has a female most likely, and most likely she's sitting on a nest. And this is actually one of the most difficult shorebirds to find on the ground. They nest in - they're very dispersed. They're not dense nesters, and they are so camouflaged. And they'll sit so tight on the nest that literally you could sit right by - beside a nest and watch the bird sitting there if you can ever find it.
GROSS: And are they camouflaging themselves so that the hawks don't find them?
VYN: Not for hawks so much on the Arctic - in the Arctic - as other birds, especially gulls and a few species of jaegers, which are sort of like gulls. But they're predatory birds that feed a lot on the nests of other birds, the nestlings of other birds in the summer up on the tundra. And in the winter, they spend virtually their entire rest of the year at sea, out of sight of land, as far south as the Sub-Antarctic. So it's another one of these long-distance migrant birds.
WEIDENSAUL: Getting back to that siren-like quality of the red knot, I mean, this is a species that's in serious, serious trouble not because of arctic foxes and jaegers and gulls, but because almost all of those red knots come through the Delaware Bay every spring. And they have timed this enormous nonstop migration so that most of them are leaving the coast - the southern coast of Brazil, making a nonstop flight to the mid-Atlantic region in the - in North America, arriving around the middle of May, just timing it so that the horseshoe crabs are coming up out of the deep water of Delaware Bay and crawling up in the beaches and digging their nests and laying tens of thousands of little fat-rich eggs. And the birds need to regain all the weight they've lost flying nonstop from South America, lay on fat that will carry them the rest of the way up into the High Arctic and have enough reserves to carry them through the first weeks of territory-establishing and courtship and nest-building because everything's still frozen up up there when they arrive. And over the last 15, 20 years, we've - commercial fishermen have taken so many horseshoe crabs out of the Delaware Bay that the horseshoe crab population collapsed. The number of eggs available on the beach collapsed. And we've seen this drastic decline in the number of red knots, which are now listed on the federal threatened species list.
GROSS: My guests are Scott Weidensaul, who contributed essays to the new book "The Living Bird," and Gerrit Vyn, who shot the photographs in the book. After a short break, we'll hear more audio recordings of birds and find out some of the things birds see that are not visible to the human eye. I'm Terry Gross, and this is FRESH AIR.
(SOUNDBITE OF MUSIC)
GROSS: This is FRESH AIR. I'm Terry Gross, back with more of our conversation about the remarkable abilities of birds. I have two guests who have contributed to "The Living Bird," a new book from the Cornell Lab of Ornithology. Gerrit Vyn goes to extremes to photograph birds and record their songs. Scott Weidensaul contributed a couple of essays to the book. He's written extensively about raptors and bird migration and is co-director Project Owlnet, which bans baby owls in order to track their migration. He wrote the new "Peterson Reference Guide To Owls Of North America And The Caribbean."
Birds seem like such remarkable animals. I mean, being able to fly is almost the least of it. You know, they fly. They sing. They travel thousands of miles and know where they're going, and they get there. They have some kind of internal GPS that I can't pretend to comprehend. But tell us some of the reasons - each of you - why you are so preoccupied with birds and have devoted, like, your professional lives to birds.
WEIDENSAUL: Because birds are really cool. I mean, it's - that's a really banal answer to it. But I've been interested in birds since I was a little kid. So, I mean, I can't tease out the moment when I became entranced by birds. But the more I learn about birds, the more astonishing they become. And you mention - you mentioned that they - they know where they're going. Actually, when they start on their migrations, they don't know where they're going. They've never gone before. Most birds, like these bar-tailed godwits making the flight across the Pacific, they're not flying with mom and dad. They're driven in that direction by an instinct that tells them to fly in a certain direction at a certain time of the year for a certain length of time. They have no idea where they're going. It's not a conscious decision. You know, in terms of orientation, we've known for the better part of a century that birds have a magnetic sense. And when I was in college in the 1970s and took ornithology, I was taught that there's little magnetic crystals in their brain that acted like a little compass and kind of pulled their nose north. And it turns out that's - there's magnetic crystals there, but they don't seem to have much to do with their magnetic sense. It now appears that birds may be using a form of quantum entanglement.
GROSS: I don't even know what that is.
WEIDENSAUL: Well, it's weird enough that Einstein described it as spooky action at a distance, where if two particles are created at the same moment, they - they're entangled and function as one thing across potentially millions of light-years of space. And this is happening in the eye of a bird in a way that allows them to visualize the earth's magnetic field. It's this bizarre hypothesis, but there's actually an increasing amount of experimental evidence to back it up. So, you know, the house sparrow that's hopping around your feet at an outdoor cafe picking up crumbs can see and hear and experience aspects of the natural world that we're blind, deaf and dumb to. They can see bands of polarized light moving across the sky in lockstep with the sun. They can hear extremely low-frequency sound waves that carry halfway around the world. There are some species of seabirds that will smell their way back to their nest burrows among millions of other nest burrows on - in the blackest of nights just by how that burrow smells.
GROSS: So I want to play another bird song that, Gerrit, you recorded. And this is the yellow-billed loon.
(SOUNDBITE OF YELLOW-BILLED LOON CALL)
WEIDENSAUL: Sitting here, listening to that recording, that takes me right back to the North Slope in Alaska, which is, you know, really one of the only places where you can find the yellow-billed loon. And birdsong - if you've experienced it, birdsong carries you right back again. And it's unfortunate; most people, I think, just sort of see birdsong or hear birdsong or experience it as this - kind of this pleasant little background soundtrack that nature provides. I was at a fishing camp with a buddy of mine a few years ago, and we stepped outside at daybreak. And it was a Baltimore oriole singing. He said, oh, he said, listen to that bird. He said, that's a happy bird. And I said, there's nothing happy about that bird. That bird is singing to establish his territory and drive away rivals and try to attract a mate. And he's come thousands of miles back from Central America to - you know, this is a matter of life and death for him. And he said, you know, jeez, Weidensaul, you can suck the joy out of anything, can't you?
WEIDENSAUL: But it's true. I mean, these - the birds - the vocalizations the birds have, they enrich our lives. And - but they're busy doing what they need to do.
GROSS: I've heard you do a loon call.
WEIDENSAUL: Yeah, poorly. That was at an Audubon Camp. That's a - just - there's a - and it was actually - it was - that was not a loon call. It was a sora, which is this little rail about 7 or 8 inches long that lives in marshes and has this bizarre, you know, geeky kind of call that...
GROSS: Would you do it?
VYN: Please, embarrass your friends and family, Scott. Let's hear it.
WEIDENSAUL: Oh, this is the last - what you're about to hear is the last nail being driven into the coffin of my career. It's sort of this (imitating bird). And it's a common sound in the marsh. And - I got to tell you, the bird does it a hell of a lot better than I just did.
WEIDENSAUL: And it's a - but it's a way, you know, in this dense habitat - in this dense marsh grass - for these soras to contact each other and keep in touch without exposing themselves because you don't want to - you know, it's a...
WEIDENSAUL: You don't want to expose yourself to a raptor or, you know, or for another predator. And so it's a way of communicating with mates. It's a way of driving away rivals. You know, it's kind of - a lot of bird vocalization is sort of a combination of a no trespassing sign and a singles ad all rolled into one.
GROSS: (Laughter) Gerrit, you have a video of loons. And in that video, you see that - you see a loon who is warming one of its webbed feet by tucking it under its wing to keep it warm, kind of like you might put your hand under your armpit to keep it warm.
VYN: Yep, yep, these birds have amazingly big webbed feet. Some birds use their wing - actually use their wings underwater - diving birds. But these birds don't use their wings, and they have these powerful feet. And they're amazing divers, and they go underwater pursuing fish. But when birds are up sitting on top of the water, most birds, you know, they can tuck their feet into their feathers, into the down, and beneath the layer of water-repellant feathers and try to warm those bare skin parts.
WEIDENSAUL: The other thing you have to remember is that birds that - like loons, that are spending time in cold water - even in the summertime in the Arctic, the water is cold. I've fallen in the water in the Arctic in the summertime, and I'm here to tell you. But they're - they've got this incredibly dense down layer. And then they've got the contour feathers, the outer layer feathers, over top of it. And they've been treated with oil that comes out of a special gland at the base of their tail that makes the outer feathers somewhat waterproof. So the cold water's not really reaching their skin. It's got this thick layer of down. And in their legs - if you've ever seen geese or gulls standing on the ice in the wintertime, you think, my God, that must be the most unpleasant thing in the world. They have - there's very little - there's very few nerves in their leg. There's very little blood circulation in the leg. And there's - and they have this arrangement of their blood vessels and capillaries that tends to keep the cold blood in their legs. It's - they're able to transfer oxygen from the cold, depleted blood and the warmer blood coming from the core of the body without bringing the cold blood all the way up into the body core, which would lower their body temperature. So it's not that they don't feel the cold, but they don't - certainly don't feel it to the same extent that a mammal would sitting - if we were sitting out there, barefoot on the ice in January. And it prevents the kind of hypothermia that would happen to us very quickly under those circumstances.
GROSS: Let me reintroduce my guests. I have two guests. Gerrit Vyn is a photographer with the Cornell Lab of Ornithology, and he did all the photographs in the new book, "The Living Bird." And my other guest, Scott Weidensaul, contributed essays to this new book and has a new book of his own called "The Peterson Reference Guide To Owls Of North America And The Caribbean." Let's take a short break, then we'll talk some more. This is FRESH AIR.
(SOUNDBITE OF MUSIC)
GROSS: This is FRESH AIR. And if you're just joining us, we're talking about magnificent birds, and I have two guests. Gerrit Vyn is a photographer and cinematographer with the Cornell Lab of Ornithology, and he is the photographer for the new book "The Living Bird." Some of the essays contributed to this book are by my other guest, Scott Weidensaul, who is also the author of a book of his own called "The Peterson Reference Guide To Owls Of North America And The Caribbean." That's just his latest book. He's got lots of other books (laughter).
Gerrit, what's the biggest risk you ever took to get the photograph that you wanted?
VYN: Well, you know, my mom is always - you know, I'm going off to these places around the world, and my mom's always worried about bears or this or that wild animal. And I constantly tell my mom that, you know, the scariest thing and most dangerous thing out there are people. I feel quite comfortable always out there with the animals. Animals have very predictable behavior, for the most part. And once you learn it, you know their body language, you know what you can do. But generally, the thing that is often the most scary is going places where people are unpredictable. And I've certainly been to some places where, you know, you feel uncomfortable. I did some hidden-camera recording in wildlife markets in southern China - in Guangdong Province a couple of years ago, where you go into some of these markets that are just full of animals from all over the world - hundreds of species - in deplorable conditions. And, you know, I was walking around with a kind of improvised hidden camera to film some of this. And that could have been a potentially dangerous situation, being - you know, it's in a pretty - not in, you know, a village where there's people visiting, you know, in a more remote kind of town. And there would have been very little recourse had they discovered me filming them because, you know, they wouldn't even let you bring your cell phone out in these kind of places for fear of that getting out. But some of the stuff that, you know, I filmed in China with wildlife is pretty heartbreaking.
WEIDENSAUL: I used to make the same comment about people being the most dangerous thing, and then we got charged by a female grizzly bear with a cub this summer doing fieldwork in Alaska, so maybe I'll change my mind on that.
GROSS: Gerrit, one of the reasons why you do what you do is that you want to document what's happening environmentally by documenting what's happening to birds. What are some of the recent signs that you've seen of climate change?
VYN: Well, I mean, birds are probably our best measuring sticks for environmental health and change. And that's one of the reasons that we look at birds. They're visible. They're everywhere and easy to count. They inspire us. People want to look at them and count them. So we're able to look at bird populations as great indicators of the health of the environments and the health of the ecosystems they depend on and, ultimately, we depend on. And certainly, you know, if everyone was birdwatchers, I doubt there'd be anyone who doubted climate change. It's just - it's something that you see with your own eyes. Where I grew up in Michigan, there were southerly birds that were very rare when I was a kid. I lived at the northern end of the range. And now, you know, they live a hundred miles - or breed a hundred miles north of where I grew up just because the winters have become milder and these birds that couldn't handle a harsher winter have expanded their range northward. I've also been working out in the Bering Sea on the Pribilof Islands where, you know, one of the groups of bird that's really showing early signs of suffering are seabirds. There's some new, just very depressing - very depressing reports on the state of seabirds around the world. And as the ocean has changed and warmed, prey species and distribution changes, and many species of seabirds throughout the world are having a very hard time raising chicks. So you see signs of this all over the place.
GROSS: So there's one bird song that I want to play that is not one that you recorded and brought with you today, Gerrit, but it's just so interesting. It's the lyre bird, and this is a bird that has amazing abilities to mimic other sounds. This is actually an excerpt of a BBC film that David Attenborough recorded. And just tell us a little bit about the lyre bird before we hear this.
WEIDENSAUL: Well, lyre birds are found in Australia, and they're mimics. And there's a lot of birds that are mimics. They pick up either environmental sounds or the sounds of other birds. And it's - the older they are and the more experienced they are and the more sounds they can mimic, it's an indication to a female that I am not just some pimply-nosed teenager that just - you know, that just fell off the boat here. And so I've been around for a long time. And it's kind of an honest indicator of the age and the experience of this male bird because you can't fake it. But, you know, so most people are familiar with northern mockingbirds. That's the famous mimic in this country, where they mimic the sounds of other birds. They can - a male mockingbird may be able to mimic a couple hundred to a thousand songs of other birds. Now, there are others, like brown thrashers that are found in the eastern U.S., that can mimic up to 7,000, but none of them mimic environmental sounds as well as the lyre bird from Australia.
GROSS: OK, so this is really remarkable. Let's hear the lyre bird as recorded by David Attenborough for the BBC.
(SOUNDBITE OF ARCHIVED RECORDING)
DAVID ATTENBOROUGH: He also, in his attempt to out-sing his rivals, incorporates other sounds that he hears in the forest.
(SOUNDBITE OF BIRD CALL)
ATTENBOROUGH: That was a camera shutter.
(SOUNDBITE OF BIRD CALL)
ATTENBOROUGH: And again.
(SOUNDBITE OF BIRD CALL)
ATTENBOROUGH: And now a camera with a motor drive.
(SOUNDBITE OF BIRD CALL)
ATTENBOROUGH: And that's a car alarm.
(SOUNDBITE OF BIRD CALL)
ATTENBOROUGH: And now, the sounds of foresters and their chainsaws working nearby.
(SOUNDBITE OF BIRD CALL)
GROSS: And all those sounds were done by the bird. That wasn't really a chainsaw. That was, like, the bird imitating a chainsaw. And I thought, this must be, like, a fraudulent video because it's impossible that a bird could do a chainsaw sound so accurately or the sound of a camera shutter.
WEIDENSAUL: But you have to understand, birds have more - far more vocal agility and flexibility than we do. I mean, for one thing, birds don't have a larynx like we do. They have an organ called a syrinx. And they can control each side of the syrinx separately. So that allows them to produce two sounds at one time, which gives them more flexibility. And, you know, when you listen to the sound of, like, a wood thrush or this - you know, these really ethereal bird songs, the harmonics are in there because the bird is actually harmonizing with itself. It's able to sing two notes at the same time. So I mean, for us, this sounds remarkable. For a bird, this is just a day at the office.
GROSS: And Gerrit, do you do bird calls?
VYN: (Laughter) You know, Terry, I get asked that all the time. And every time, my answer is, not in public. But I might consider doing one bird call for you.
GROSS: Oh, would you, please?
VYN: (Laughter). Your studio engineer might want to turn the levels down a hair, but I'll do the ascending hoot of the bard owl that we heard earlier.
(Imitating bard owl).
GROSS: That's great. Can your bird calls attract birds?
VYN: Yeah, yeah, yeah. So you can definitely do owl calls if you do them well enough, and owls will respond or sometimes come closer.
WEIDENSAUL: What you've got to realize, though, is that...
GROSS: And do you feel, when you do that, that you're communicating with the bird, that you're creating a connection?
VYN: Well, you're not really creating a connection. Really, what they're hearing is that, oh, there's another owl in my territory, and I need to go run it off.
GROSS: Oh (laughter).
VYN: So really, you're disturbing them in some way. So it's not something...
GROSS: You're inciting them.
VYN: Yeah, so it's not something you want to do all the time. You know, with owls, it's sometimes special to be able to show people owls.
WEIDENSAUL: It is a very cool thing to be in the woods at dusk and belt out a bard owl call and have a bard owl respond in the distance and come flying in, all puffed-up and angry, to see who's trespassing in his territory. It's - you know you're not communicating with them in any meaningful sense, but there is - there's definitely a feeling of connection there.
GROSS: I want to thank you both so much. It's been just so fun and educational to hear what you had to say about birds. And Gerrit, thank you for bringing all those bird calls with you and for recording them. It's been great. Scott Weidensaul, Gerrit Vyn, thank you so much.
WEIDENSAUL: You're very welcome. Thanks for having me.
VYN: My pleasure.
GROSS: Gerrit Vyn shot the photographs in "The Living Bird," a new book from the Cornell Lab of Ornithology. Scott Weidensaul contributed essays to the book. I'm Terry Gross, and this is FRESH AIR.
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