Conservation Biologist Explains Why 'Feathers' Matter

September 4, 2012

Guests: Mickey Edwards – Thor Hanson

TERRY GROSS, HOST: This is FRESH AIR. I'm Terry Gross. The political conventions are all about getting your vote and convincing you the other party is responsible for some of our country's greatest problems. But it's the party system itself and the ongoing battle between Democrats and Republicans that is at the heart of our political mess, according to my guest, Mickey Edwards.

In his new book, "The Parties Versus the People," he writes that party leaders control important committee assignments in Congress, control legislative priorities, provide or withhold money for re-election campaigns, and mete out rewards and punishments to legislators, creating a climate that creates extreme partisanship and makes it difficult for legislators to vote their conscience.

Edwards is a former legislator himself. He was elected as a Republican congressman from Oklahoma City in 1976 and served 16 years. But now he works in pursuit of bipartisanship as a co-founder of No Labels and The Aspen Institute.

Mickey Edwards, welcome back to FRESH AIR. Just give us an overview of why you think political parties are the cancer that's ruining politics in America.

MICKEY EDWARDS: What I've seen, Terry, recently is that the parties have become so dominant in determining how individual members of Congress vote that it doesn't really matter what the issue is, it doesn't matter whether you're talking about a stimulus plan, a budget, confirmation of a Supreme Court justice. On almost every major issue now, all the Democrats are on one side, all the Republicans are on the other side, and it's obvious that they're not really analyzing the issue in terms of what information they've been able to get, what their own analysis is, but where does my party stand, because my goal here is to be true to my party, to defeat the other party, and there is no way that you can actually manage a government of 300 million people with people in Congress, or in state legislatures as well, who are unable to - and unwilling to really look at the issues in front of them, figure out what needs to be done, and take the oath of office seriously.

GROSS: Let's look at some of the powers that party leaders have in Congress. Party leaders get to choose committee chairs. What's the significance of that?

EDWARDS: The way that Congress works is that almost every major issue comes first through the committee structure. And the people who run the committees are able to decide who we're going to bring forward as witnesses, who we're going to hear from to make the record, whether or not we're even going to let a bill be considered in the committee in order to move it forward to get to the House floor.

And I've been there. I've been in the room. I've watched when you are discussing whether or not A or B ought to be on Ways and Means or Appropriations or the Labor Committee. And somebody will say no, we're not going to put that person on that committee because whatever his or her constituency or personal views or expertise, that person's not going to stick to the party line on the issues that are part of our platform, that are part of our agenda. So that's part of it.

But you sit on these committee staffs, where you're dealing at the first instance with every kind of a major issue and you're sitting there with staff that is either Republican staff or Democrat staff, rather than having, as some states do, and a lot of countries do, nonpartisan staff.

You're operating under the direction of whoever happens to be speaker of the House, who is - who sees his or her view as to be a partisan leader rather than the manager of the process, so that you have - it doesn't matter whether you have a country that is in recession or that is in the middle of wars. You'll have a Republican leader like Mitch McConnell say that my job is to defeat Barack Obama. You'll have a Democratic leader like Nancy Pelosi say to the president, well, we won the election, we'll write the bills, when he was trying to act in a more bipartisan way.

GROSS: How do you think committee chairs are appointed? What do you think the party leaders look for before making a decision?

EDWARDS: The best example that I saw when I was there is that when Newt Gingrich became the speaker, and this has been a pattern, to concentrate power as much as possible in the hands of a speaker who is looking for somebody who would be a champion of the party line.

And so it became common to pick somebody for a committee chairmanship not based on years of experience, expertise in a particular issue, but whether or not they were going to be sufficiently strong advocates for the party point of view rather than who is going to try to manage the process in order to allow the issues to be brought forward, the best witnesses and experts to testify, and allow the members to make up their own minds.

GROSS: Well, you credit Newt Gingrich with creating other, new ways to wield party power and keep lawmakers in line. What are you thinking of?

EDWARDS: What I think, Terry, is that the word credit is not the right word because, you know, I'm very critical of Newt.

GROSS: Right.

EDWARDS: Newt Gingrich actually did a lot to change the nature of the Congress in making it more - there had always been partisanship, but nonstop partisanship, partisan on every issue, bringing issues to the floor that had no chance of passage but only to embarrass members or to put them at odds either with their party leadership or with the folks back home, requiring - he started the process of requiring individual members to raise what's now $300,000 a year besides their own election campaigns just to knock off the opponent.

So Newt kind of began this process of you look at somebody on the other side not as a fellow member of Congress but as an enemy to be vanquished.

GROSS: You write that Newt Gingrich required members of the Appropriations Committee to sign a written pledge that they would heed the Republican leadership's recommendations for spending reductions.

EDWARDS: Well, yeah, and it was not only that, Terry, but there were actually in Congress some very competent people - Jimmy Quillen from Tennessee was one, who was the ranking member of the Rules Committee; Carlos Moorhead from California also ranking member of committee - who were bypassed for chairmanships solely because they were not considered aggressive enough, and not aggressive enough in trying to get a policy passed but to stick with the party platform against - you know, against whatever their own mindset told them or whatever the information told them.

They could not be counted on to be true blue - you know, not about being true blue to the country, but they can't be counted on to be true blue to the party.

GROSS: And you write that Gingrich's reforms when he was the House speaker were really more like purges.

EDWARDS: Well, they were like purges. He purged, you know, Jimmy Quillen and Carlos Moorhead, but he purged other people as well. It was we're the party, this is about party, it's nonstop about party, our party against their party, and if you want to be a player - you know, this happened to Marge Roukema in New Jersey, it happened to other people - if you didn't give - if somebody else gave more money to the party than you did, then you're not going to get the position.

If somebody else has done more to advance the party, rather than a piece of legislation, than you did, you're not going to get the position, because it's all about party.

GROSS: If you're just joining us, my guest is Mickey Edwards. He's the author of the new book "The Parties Versus the People: How to Turn Republicans and Democrats Into Americans." You described some of Newt Gingrich's reforms when he was House speaker as actually being purges and, you know, ways to just, like, control Republican votes. How much of the changes he put into place are still there? And do you think things have gotten even more in favor of party leaders controlling the vote?

EDWARDS: Well, my concern is not so much party leaders. I hope people are willing to say I'm not going to follow the leader. You know, the greater concern here is not party leader but party. And let me give you an example of what I mean, Terry.

You get people in Congress, both sides, who are committed to sticking with a particular ideology or with their team and unwilling to compromise. Well, how does that happen? It happens because the incentive system works, and what we've created is a system in which in order to get elected, you have to first make your way through a party primary dominated by the people who are the most ideological, the most partisan, and you're not really concerned about your election to appeal to the broad range of voters in your state or in your congressional district but to those who are going to vote in the primary.

So that you had this example, and just a couple of quick examples, but in Delaware, when Christine O'Donnell was running against Mike Castle, Mike Castle was one of the most popular people in the state, he had been governor, he'd been a long-term congressman. The people of the state liked him a lot, but in that state of a million people, only 30,000 voted in the primary. He lost the primary to those 30,000, and therefore the rest of the million people didn't have him as one of their options.

So that's how you run into (technical difficulties) in Missouri, who made it through a narrow partisan primary and ends up as the nominee who was on a path to maybe get elected to the U.S. Senate. Or Utah, with three million people, and 3,500 of them show up at a convention. They don't vote for the incumbent senator, Robert Bennett, he can't be on the ballot anymore.

Terry, that's the problem. We're allowing these clubs, the narrow subsets of the population, to dictate to the general public when they go to the polls in November about who their choices can be.

GROSS: So you're saying in part that primary voting tends to lean more toward extremes than the actual election. Why is that?

EDWARDS: Well, yeah, sure. In Indiana, in order for Mourdock to beat Dick Luger, you know, what he did was say I'm not going to go to Washington to compromise. I don't believe in compromise. Well, you know, as I've said, 300 million of us, compromise is the way you have to eventually - that's what Ronald Reagan did. You have to move the country forward.

He believed in compromising when it was necessary, and so, you know, Washington State in 2006 said we're not going to put up with this anymore. And they voted to do away with these party - closed party primaries. California in 2010 voted to do away with party primaries and say let's give the voters all the choices. Let all the candidates run on one ballot, maybe two Republicans, three Democrats, Green, Libertarian, whatever, and let all the voters choose.

And then you end up with people in Congress, in the House, in the Senate, who are representative of the people, not representatives of small subsets of the people.

GROSS: So does everybody get to choose one Democrat and one Republican? Like how does that work?

EDWARDS: No, no, no. I mean, what you do, you have a runoff between the top two. If you have everybody running on the same ballot, and nobody gets over 50 percent, you have a runoff. It's basically a general election, but it's a two-tiered general election. The first one, everybody's on the ballot, the second one, you have a runoff between the top two.

It could be two Republicans against each other. That's happened in Louisiana. It could be two Democrats running against each other. It's happened now in a district in California. It could be any number of people. What matters is the people themselves will have made the choice of who they like best.

Can I tell you a personal story?

GROSS: Sure, please.

EDWARDS: I'm from a city, I'm from Oklahoma City, a pretty good-sized city, and I'm very much an urban guy. I was the first Republican elected from my congressional district since 1928, and my district was three-fourths Democrats. And so when I won as a Republican, it drove the Democrats crazy. And by the way, when I say this, I'll just tell you, Republicans are just as bad about this as Democrats are.

Because they couldn't beat me, the legislature decided to redraw my congressional district from Oklahoma City instead all the way up to the Kansas border, halfway across to the Arkansas border, a big upside-down L, and Mickey Edwards, the city guy, was now representing wheat farmers, cattle ranchers, small-town merchants.

And I tried really hard, but I could not be an articulate advocate of their concerns.

GROSS: Because you didn't understand those - you were an urban guy, and they were farmers, and...

EDWARDS: They were farmers and ranchers, and they had different kinds of concerns economically, different ways of looking at things. But one of the things that happens when you have a situation like that is that you end up - you go against maybe the most important single principle in the Constitution, and that is a provision in the Constitution that every single U.S. senator and U.S. representative must be an actual inhabitant of the state from which they're elected, not like in Britain where you can represent Manchester and not even be able to find it on a map.

The idea was you would know your constituents, you would know their concerns and their interests, and they would know you, because you lived there. And this, allowing parties to draw congressional districts for their own partisan advantage completely undercuts that basic fundamental principle of American government.

GROSS: How much control do parties have over redistricting?

EDWARDS: In almost every state, redistricting is done by the state legislature, which is - you know, essentially means by the majority part in every state legislature. And that's why you see, long before a presidential election or congressional elections, you'll see a state legislative election, and one party or the other will control - will win control of a State House or a State Senate, and the observers, the reporters, will say, you know, here's the effect that could have on the next Congress, because you assume they're going to draw district lines that are going to help increase their number of members in Congress.

So they have a lot. Now, 13 states, most recently California, said we're going to do away with party control of redistricting. And they've gone to independent, nonpartisan redistricting commissions. Most states haven't done that yet, but - you know, I really think the process has begun to change all of this.

GROSS: If you're just joining us, my guest is Mickey Edwards. He's the author of the new book "The Parties Versus the People: How to Turn Republicans and Democrats Into Americans." It's a critique of the political party process and the amount of power that parties have. And Edwards is a former Republican congressman. So let's take a short break here, and then we'll talk some more. This is FRESH AIR.

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GROSS: My guest is Mickey Edwards. In his new book, "The Parties Versus the People," he makes the case that the political party system and party leaders are behind the divisiveness in American politics today.

You spent 16 years in Congress as a Republican congressman. You're still a Republican. And I'm wondering what you think of the direction your party is taking.

EDWARDS: Well, I think that because of the system that I describe - I think it's true of both parties - that they're taking positions that are less open to finding common ground, less open to finding areas of compromise, and that's what's really bothersome.

Now, have their positions changed? Sure. I mean I was told by a political scientist that when I was in Congress, I was one of the most conservative members of Congress, and that if today, if today I were in Congress and I didn't change my vote at all, if I voted on exactly the same issues and voted exactly the same way I did then when I was chairman of the American Conservative Union, you know, that I would be one of the most liberal members today in the Republican Party.

So the party has changed. It has definitely moved to the right. But the way it has moved to the right and the way the Democrats today have fewer members who are willing to compromise and talk to the other side is because of this closed party primary system that's on both sides. And so that's fueled the change. That's made the change possible.

You - it's not that the people have become more ideological, it's that the people who get elected through this system have become more ideological, because that's who can win the primaries and get on the ballot.

GROSS: In 2008, when you and I first spoke, you were supporting Barack Obama for president, even though - actually he had just won, but you had supported him, even though you're a lifelong Republican. Where are you now? Do you care to say, or would you rather not?

EDWARDS: Well, you know, the reason I supported Obama was because I felt - there were a lot of his positions that I disagreed with. I supported Obama because I really thought that George W. Bush's presidency needed to be repudiated. And that wasn't - it had nothing to do with spending or that. You know, it had to do with a very cavalier attitude toward the Constitution, and whether it's habeas corpus or as I just talked about, you know, saying I'm president, I don't have to obey the laws, I was just shocked. I was just shocked.

And I felt it was really important to repudiate that. So I was not - you know, I didn't support Obama because I necessarily supported his policies. You know, so I'm going to watch and see what happens. I'm going to watch this campaign, and I'm going to see what people are proposing.

GROSS: Mickey Edwards, thank you so much for talking with us.

EDWARDS: Thank you, Terry, I've enjoyed it a lot.

GROSS: Mickey Edwards is the author of the new book "The Parties Versus the People." You can read an excerpt on our website, freshair.npr.org.

I want to let you know that Friday we're going to rebroadcast an interview with Hal David, the lyricist who collaborated with composer Burt Bacharach on many great songs. Hal David died Saturday at the age of 91. He said his favorite of all his lyrics was this one, "Alfie." Here's Cilla Black's 1966 recording. I'm Terry Gross, and this is FRESH AIR.

(SOUNDBITE OF SONG, "ALFIE")

CILLA BLACK: (Singing) What's it all about, Alfie? Is it just for the moment we live? What's it all about when you sort it out, Alfie? Are we meant to take more than we give? Or are we meant to be kind? And if only fools are kind, Alfie, then I guess it is wise to be cruel. And if life belongs only to the strong, Alfie, what will you lend on an old golden rule? As sure as I believe there's a heaven above, Alfie, I know there's something much more, something even non-believers can believe in..

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TERRY GROSS, HOST: This is FRESH AIR. I'm Terry Gross. Evolution has given the creatures that inhabit the earth a number of skin coverings, scales, fur and skin, for example; but one of the most remarkable, our guest Thor Hanson says, is the feather. In his new book, Hanson traces the evolutionary origin of feathers, noting that they probably adorned some dinosaurs. He explains how feathers keeps birds warm in freezing temperatures and cool in blazing heat, how they function in attraction and mating, and how they enable flight.

Thor Hanson is a conservation biologist who has studied birds around the world. His first book, "The Impenetrable Forest," was about guerrillas in Uganda. His book, "Feathers: The Evolution of a Natural Miracle," just came out in paperback. He spoke with FRESH AIR contributor Dave Davies.

DAVE DAVIES, HOST: Thor Hanson, welcome to FRESH AIR. In the book, you describe an experience you had observing vultures, which kind of inspired you to look more into feathers. You want to tell us that story?

THOR HANSON: Yes. Well, that story occurred some years ago now. But I was working on a vulture project in Kenya and the project involved studying the feeding habits of vultures. Which, if you've never done it, tends to involve moving around a lot of vulture food in wheelbarrows and such. So here I was with a wheelbarrow full of zebra remains in the hot African sun, and after transporting that stuff around and slopping it hither and yon, I ended up covered with the blood and guts and the gore, so to speak. And I realized, of course, that in that moment I was very much like a vulture myself. But, of course, with my long ponytail and my T-shirt and my jeans I wasn't a very well adapted to the lifestyle. I was covered with the stuff and it got me thinking.....

DAVIES: And I just - I hate to interrupt you, but I don't want you to leave out a couple of details. The stuff was like two days old, right the zebra remains?

(LAUGHTER)

HANSON: Yes.

DAVIES: And you are...

HANSON: Yeah we got, we...

DAVIES: You're handling this bare handed, right?

HANSON: Yeah. Well, we typically would go to this slaughterhouse where they would save things for us. But we showed up one day and they were closed but they had just left everything in the side yard. And so here was this heap of animal intestines and hoofs and bits of zebras and we hadn't brought anything to put that into the trailer. They usually did all of that for us. So here we were and we had to get it in there somehow. So we were heaving stuff into the trailer and getting it in the wheelbarrow and it was a sticky, sticky, stinky mess.

So at any rate, this got me thinking about vultures and their feeding habits and the advantage of having a bare head. I had originally been wondering what would make a bird lose something so inherent to its nature as its feathers. And of course, in this case for the vultures is this awful stuff they're eating every day, and having lost their feathers, that allows them to remain much cleaner and much free from - more free from bacteria and parasites and disease.

DAVIES: Now there are a lot of different skin coverings we see in the natural world. I mean some creatures have scales, we have hair, some have fur. What's so remarkable about feathers?

HANSON: Ah, so many remarkable things. So many. But I think if you want to boil it down to one comment, and it is this: there are many, many things in nature that are beautifully adapted to a single purpose. But almost nothing has adapted to so many purposes as feathers. Those other skin coverings that you mentioned are marvelous in their way but you don't see them with the diversity of structure and function that you find in feathers. You have a feather that can be the finest insulation that we've ever discovered. You have feathers that are wonderfully waterproof, structurally waterproof. You have feathers that are beautifully adapted to flight-perfect airfoils. You have feathers, of course that's our wonderfully adapted for display with incredible iridescent colors, long flowing plumes. So the diversity of form and function in feathers is truly unique.

DAVIES: All right. Let's talk about understanding the evolution of feathers. And it's interesting, you know, fossils preserved bones well. Feathers, not so well. What do we now think we know about how feathers appeared in the evolutionary chain?

HANSON: Well, we are probably as close to some kind of scientific consensus as we ever have been about the evolution of feathers and evolution of birds, because the quality of the fossils coming out of China and the feather specimens that are preserved there, tells quite a lot about how they evolve and where they evolved. And that it does appear that all the stages of feather evolution, those steps necessary to build the complex modern plume occurred in a lineage of dinosaurs called the theropods, the meat eating dinosaurs. It's a group that includes such famous dinosaurs as Tyrannosaurus or the Velociraptors from "Jurassic Park." That story has gained a lot of new evidence based on the fossils now coming out of China.

DAVIES: And it's fascinating that these were not flying creatures, right, but we think they may have been what, covered or partially covered in feathers?

HANSON: Yes. There's great evidence, now, for feathers evolving in the theropods. And the creatures were primarily runners - they had long, strong, long, strong overdeveloped, marathon-runner legs, and walked on two legs and ran on two legs, which freed up their arms, perhaps, by one of the theories, to be feathered and used eventually for flight. But one thing that we really believe now about the evolution of feathers is that the simplest feathers - the first feathers in the series of steps towards building a complex vein feather - were not aerodynamic. So the first uses of feathers must have been for other purposes. And what's really amazing about the quality of these fossils is they are actually able to determine in some cases the colors of those early, early feathers which gives real credence to the idea that an early use for feathers was display a color.

DAVIES: You know, you described de-feathering a Wren, a little bird that, what, that you're in the habit of picking up birds and putting them in your freezer? Is that right?

(LAUGHTER)

HANSON: Yeah. The freezer is a, it's a complicated place in our household. You dive in there for a bit of ice cream, you might come out with a vole or a woodpecker.

DAVIES: And the family has gotten used to this, huh?

(LAUGHTER)

HANSON: My wife is very patient.

DAVIES: Well anyway, so you did post this Wren and pluck the feathers. Just describe a little bit about that experiment, kind of what it told you about feathers and birds.

HANSON: Well, in all this research about feathers I realized, you know, I really need to disassemble a bird, essentially, to get my head around this diversity of form and function. I need to look at these things in detail and see how they're arranged on a specimen. So I went to the freezer and sure enough I had a specimen there that fit the bill. And I headed down to my office with the only reference I'm talking I could think of "The Joy of Cooking," and looked up how to pluck a bird, and by gosh, I set to work on the thing. And it took me hours. There is a fellow in Ireland who holds the world record for plucking a bird. He can do a turkey in about a minute and a half. So it was ours for me to get through this Wren but I learned a great deal from doing so in terms of how the feathers are arranged and how many different types, and just how many there are on a bird for this tiny Wren. I had well over 1,500 feathers by the time I was done, an incredible number of feathers and it's a real testament to their importance for birds that in general the weight of their feather coat out ways to dry weight of their skeleton by more than two to one in most species.

DAVIES: Yeah, you were struck by when you pluck the feathers how little bird there was left.

HANSON: That's absolutely right. The poor bird was, you know, the remainder was just a bedraggled little carcass where I had piles of feathers all over my desk.

DAVIES: We're speaking with Thor Hanson. He is a conservation biologist and has a new book called "Feathers."

We'll talk more after a break. This is FRESH AIR.

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DAVIES: if you're just joining us, we're speaking with conservation biologist Thor Hanson. He is a conservation biologist and has a new book called "Feathers: The Evolution of a Natural Miracle," is now out in paperback.

I want to talk about some of the ways that feathers function in animals. But first, tell us what are feathers made up? What's their structure?

HANSON: Well, feathers are a protein. There made of keratin. It's a specific keratin to feathers, but it's similar in general to the character that makes up our fingernails or our hair. Keratin is a very common protein in nature because it's tough stuff. And so you find it in the skin of animals or in these hard and horny surfaces or hair, things that have a protective function. So feather proteins one that is very well suited to feathers because it is lightweight and very durable and very tough and it takes color well. So it is a protein-based structure.

DAVIES: So the shaft grows and then the little one you call?

HANSON: The barbs.

DAVIES: The barbs coming off - come off the feather in a variety of ways and then they interlock as they grow, right?

HANSON: That's right. The growth of feathers is truly remarkable. Now we know how hair grows, more or less, it rose from a follicle. But it's a simple process compared to feathers in that hair is just a bunch of dead cells stacked on top of one another and they come out of the follicle. And we know they're dead cells because we don't bleed when we go to the barber unless we have a very clumsy barber. But on the other hand, feather growth is very complicated and when feathers are growing, in fact, they are infused with blood because it's a complex process. If you injure the pin feather, the growing feather of a bird, that's quite a significant injury, it will bleed a lot. It's only after that growth is completed that the blood vessels are retracted from the base of the feather. So while it's growing it's alive because you have this complex sort of helical process going on with the feather barbs goingError! Not a valid link. from around the sides of the follicle and been attached to the rachis, that's the central set shaft. So because it's so complex you can do a lot of complex structural things with it. You can make these incredibly branched and delicate structures that have so many functions.

DAVIES: All right. When you really want to stay warm in the winter you get a down quilt, I guess a goose down. Why are feathers particularly good at keeping birds and us warm?

HANSON: Well, feathers are to this day, they are the most efficient insulation known. We haven't been able to match them with synthetics. And I think it boils down to that growth process and the fact that you can make these fine, fine branch instructors. The key to insulation is what they call loft. How much air can and you hold in a small space? And because feathers are so beautifully and find the branch, they can hold a great deal of tiny, tiny air pockets in that branch structure. And that's what people try to mimic with synthetics but we haven't been able to match feathers for that yet because it's difficult to manufacture finally branched structures.

DAVIES: Now there are seabirds that you say always stay dry because the feathers amount to waterproofing. And you described a story, once, of finding a seabird on a highway, a murre . Is that what it is, a murre?

HANSON: Yes, a common murre.

DAVIES: Right. And you say that when you picked it up you wanted to make sure that before you tried to return it to those sea that none of its feathers were disturbed because well, why would that be the case? Why couldn't you take it back to the water if feathers had been rearranged or disheveled?

HANSON: Well Mir and other seabirds occasionally when they're flying over land they will mistake a road or a parking lot for water and they will land. And again, the real danger to them if this happens is that they damage their feather coat because you can't put one of those little birds out in the icy water with a damaged feather coaching over its belly because of the water touches the skin of that bird that thing is going to suffer immediately from hypothermia. The birds must maintain a waterproof feather coat at all times. And the way they do it is really quite remarkable. For many years, ornithologists believed that birds maintained waterproofing by applying preen oils to their feathers and that the oils must be repelling the water. And the oils play a role that they play a small role. Because what's been learned is that you can wash all the oil off of a contour feather and then drop water on it and it bead up and wash away. You know, you can scrub that feather with acid and remove everything and leaving only the structure of the feather its south and the structure is waterproof.

DAVIES: If you're just joining us, we're speaking with conservation biologist Thor Hanson. His book, "Feathers: The Evolution of a Natural Miracle" is out in paperback. Well, let's about flying. How do feathers permit birds to fly?

HANSON: Well, feathers are beautifully adapted for flight, but we do know now that flight came after the feather, in that the earliest stages of feathers were not aerodynamic. It's only the most advanced stages in feather evolution that have that aerodynamic structure.

But ultimately, the result of all of this evolution is an incredible adaptation for flight. If you look at a bird's wing it has a particular shape that is similar to the shape you would see if you looked out the window of an airplane and that is an airfoil-shaped wing with a curved upper surface that gives that wing a bit of extra lift in the air.

And a bird wing has that shape, just as an airplane wing does. But what's amazing about a bird wing is that the individual flight feathers are also shaped like airfoils. You can see these feathers. They're often the ones that you might find on the ground that have been shed by a bird. The long tapering, beautiful flight feathers of a bird are airfoils.

So what you get for a bird wing is an airfoil made up of airfoils and the bird has muscle control over all of those feathers. So it can constantly adapt and change the position of feathers and the shape of the wing to react to any change in air temperature or wind direction or air pressure, making it a truly incredible way to fly.

DAVIES: Now, all right. So in addition to, you know, insulation and waterproofing and flight, feathers make for very colorful plumage. And of course a lot of birds will use them to attract mates. And I wonder why is it so often in the natural world that it's the females that have these bland, camouflaged, you know, paler colors but the males who are so bright and ornate?

HANSON: Great question. So this boils down to a very important theme throughout nature and that can be summarized as this: Females are choosy. Females are choosy and so they have the ability to choose a mate and because they can choose a mate, it produces competition among males.

And once you have it set up where females can choose a mate, then you see competition among the males. And in birds, that competition has resulted, in many instances, in incredible feathered displays. So that choosiness on the part of the females is what they call sexual selection, another one of Darwin's great ideas. Really, his second great contribution to evolutionary theory.

This idea that the choice of mates can drive evolution and it's very clear in birds. He spent four chapters on this in one of his books, in the colorful displays of the males and their wonderful feathers. You see it in the birds of paradise, you see it in a wide range of birds where the males are incredibly plumed, in some cases to the point where they're so ornate they seem they can hardly function.

I mean, look at the display of a peacock, for example. And so that has driven this wild variety of colors and displays. And on the other hand, you often see in those instances the females retaining a much more drab coloration. Well, that has an evolutionary purpose too, in that for many bird species it is the females who are sitting on a nest to brood the eggs.

And if you're going to be sitting there on a nest all day it's a much better idea to blend in than to look gaudy.

DAVIES: Well, Thor Hanson, it's been really interesting. Thanks so much for spending some time with us.

HANSON: Well, thanks for having me on and thanks for all the great questions.

GROSS: Thor Hanson spoke with FRESH AIR contributor Dave Davies. Hanson's book "Feathers" just came out in paperback. You can read an excerpt on our website freshair.npr.org. Coming up, Ken Tucker reviews the new album by Ian Hunter, who was the lead singer of Mott the Hoople in the late '60s and early '70s. This is FRESH AIR.

(SOUNDBITE OF MUSIC)

TERRY GROSS, HOST: Ian Hunter has just released his 20th studio album and that's not counting the ones he made with the band that made him famous, Mott the Hoople. Despite the title of his new album, "When I'm President," Hunter has said the album isn't nearly as political as his past couple of solo albums. Rock critic Ken Tucker says Hunter's new music reaches back into rock's past while linking it firmly to the present.

(SOUNDBITE OF SONG)

IAN HUNTER: (Singing) I had enough of them plastic bags. You can't read them anyways. You can't watch them. You can't listen. Trash television. Trash television. I had enough of counting sheep. Buying that magazine, read 'em and weep. What you read is what you know. Down around a letter, you got to write a letter home.

KEN TUCKER: Recently, I was listening to a new tribute album covering the songs of Fleetwood Mac, and thought once again how dreadful most tribute albums are. How they not only don't add much to the legacy of the artists being saluted, the covers inadvertently freeze vital old music in an amber of sentimentality.

Then I turned to "When I'm President," an album of new songs by Ian Hunter. Hunter's band Mott the Hoople put out its first album in 1969; Fleetwood Mac made its debuted just a year before, in '68. But Hoople co-leader Ian Hunter would have no use for a tribute album. Now in his 70s, he's too busy making prickly, energetic new music that both culls from the past and resides merrily in the present.

(SOUNDBITE OF SONG, "COMFORTABLE")

HUNTER: (Singing) Imagination is all in the mind. Why don't you come up and see me sometime? I get, we get on the floor and we can slip into something more comfortable. Imagination's up in the air. You want stretch it, it'll go anywhere. I bet those twins ain't authentical(ph). Why don't we slip into something more comfortable? What's that sound? What's that sound? The Flying Scotsman's back in town. Can you hear that lonesome whistle call? Why don't you slip into something more comfortable?

TUCKER: All hail rock 'n' roll, why don't we slip into something more comfortable, Hunter sings toward the end of that song. What that means for him is everything from Jerry Lee Lewis piano chords from his backing group here - an assortment of session pros dubbed the Rant Band - to the Bob Dylan-style vehemence of "Black Tears." In that one, the emissions from a woman's eyes are called, in a nice turn of phrase, tiny little accusations trickling down your face.

(SOUNDBITE OF SONG, "BLACK TEARS")

HUNTER: (Singing) Black tears fall (unintelligible) just another weapon in your arsenal of fear, little beads of misery that kill me when you cry. Let me the kiss the circles better underneath your eye. Black tears dancing in the rain. You can't see me stop them. Here they come again. It ain't funny when the levee breaks you could drown a river, baby. You could raise the rain.

(Singing) I watch your blue eyes turning into green eyes. I watch your green eyes turning into sad eyes. Yeah. I watch your sad eyes turning into red eyes. I watch your red eyes turning into black eyes.

TUCKER: Hunter spent part of his Mott the Hoople years expressing a British man's yearning for the freedom of America, mythologizing cities in a song such as "All the Way from Memphis" or, on an early solo album, "Cleveland Rocks."

On his new album, he has a song called "Wild Bunch," and if you wondered whether he's invoking the all-American Sam Peckinpah film, the references to outlaws and a quick verse from a hymn used in that movie - "Shall We Gather at the River" dispels any doubt. Which leads, inevitably, to that most American of themes here, the title song "When I'm President."

Being British-born, Hunter can't really occupy the office, but he can have fun imagining, as he puts it, leaning on the 1 percent to get elected and seeing his grizzled old mug on Mount Rushmore.

(SOUNDBITE OF SONG, "WHEN I'M PRESIDENT")

HUNTER: (Singing) Well, mother, I'm a stranger in a strange land. I feel like an alien. It's like I'm on the outside looking in. I don't seem to fit in. Well, maybe I'm Aladdin with a rusty lamp. The genie never stood a chance to make all my wishes come true but here's what I want to do.

(Singing) I'm going to lean on the 1 percent when I'm president. I want a 20 acre (unintelligible) when I'm president.

GROSS: Hunter's dodgy moments on this album are songs sung from the point of view of the Native American Crazy Horse, and a Bruce Springsteen-y sing-along called "Just The Way You Look Tonight" at the moment when he makes the phrase only two lovers could tell rhyme with in-ev-i-ta-ble. On second thought, I kind of love the stretch he exerts to try and make that work.

TUCKER: That's the thing with Ian Hunter these days. He's at once crafty and mindful of craft, striving mightily to make his music seem tossed off. Which is what the best pop musicians of any age do. He should give Carly Rae Jepsen a call and do a duet, maybe.

GROSS: Ken Tucker is editor-at-large for Entertainment Weekly. He reviewed the new album "When I'm President" by Ian Hunter. You can download podcasts of our show on our website freshair.npr.org, and you can follow us on Twitter at nprfreshair and on Tumblr at nrpfreshair.tumblr.com.

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