Ask Sam: Caterpillar Legs, Living Fossils, & Sam Ruins Hybrid Cars

ask-sam_wArrow.gif

It's that time of year again! Actually, this time of year comes more often than other times of year tend to. In so far as we do it whenever that 'ol Ask Sam inbox starts piling up with questions from you, dear listeners! In this one, Sam and a couple of the Outside/In producers are tackling your questions about disappearing caterpillar legs, animal sexuality, living fossils, elevator efficiency and craaaaazy biking habits. Whew! Let's hit it.

 

 

Question 1: Aaron from Sandiego, CA asks:

“When a caterpillar becomes a butterfly… caterpillars have a bunch of little legs but butterflies only have six legs. I’m like, where do all the legs go?”

caterpillarlegs.gif

What a perfectly wonderful way of asking this question! Really we’re talking about metamorphosis, here, and how the heck does it work? Perhaps you’ve heard Radiolab’s meditation on this question, and if you have you’ve likely come away with the impression that caterpillars become a pupa, dissolve into a puddle of goo on the inside, and then re-form as a butterfly. As I’ve interacted with caterpillar enthusiasts through the years, they often politely inform me that this is a bit of an oversimplification. (To be fair, the Radiolab in question is really a beautiful meditation on the Ship of Theseus Paradox rather than a detailed description of the mechanisms of metamorphosis.)

But, where do the legs go? What we’ve seen in recent years, thanks to advanced imaging technologies, is that many of the “structures” that butterflies and caterpillars share — breathing tubes, digestion, etc — are reshaping themselves dramatically, but don’t actually completely dissolve into “goo.” And it turns out the legs are one of those “structures.”

 
 

Which gets us to the main misunderstanding that prompts this question: caterpillars have a bunch of legs, and butterflies only have six. Believe it or not, that’s not true! Caterpillars have six “true legs” up front and then toward the back they have any number of “prolegs.” (This gives us the opportunity to link gratuitously to the beautiful photos of New Hampshire’s Caterpillar Lab.) My favorite Twitter insect biologist Gwen Pearson calls the prolegs “blurpy, blobby legs”... like if you could use a roll of fat for your locomotion. Those prolegs will liquify and be put to use building other parts of the butterfly, but the true legs will eventually become the butterflies legs.

Ta-da!

Question 2: Anonymous from Montague, MA asks: 

“I’ve heard about some animals being pretty gay. And sometimes they only mate to make baby animals… otherwise they hang out with other genders, just for fun. So basically, how queer are animals, which ones are the gayest? I’d love to know."

We joke that we should be thankful our listeners who call in with their questions prefer to get answers from us rather than simply googling their questions. This is one of those cases, because a quick search will connect you with what is perhaps the greatest wikipedia page of all time.

To get us up to speed on this one, we called Carin Bondar — TV host, TED talker, and author of two books on animal sex. She said, “In the animal Kingdom, I frankly have yet to find an animal who isn’t at least a little bit gay. They are all queer.” Indeed, if you want lots of touching accounts of same-sex bird partners pairing up to rear an adopted egg or chick, you should set aside about 10 minutes to peruse that wikipedia page, or even better, read the New York Times account of two captive penguins named Roy and Silo.

Rams.jpg

We should note, that overwhelmingly animals are actually bisexual; they are willing to have sex more or less indiscriminately with whoever else is up for it. Exclusive homosexuality — as in animals that will refuse to mate with animals of the opposite sex — has only been observed in sheep. (Quick science caveat here: “observed” is an important word in that sentence. There could be plenty other gay-not-bisexual animals out there… but it’s hard to observe every waking moment of every wild animal’s life.) Depending on the study, somewhere between 7 and 10 percent of rams will reject ewes and only mount other rams.

This question also alludes to the fact that there are many animals that don’t really like to hang out in coed groups the the same way that we do. Female albatross, for instance, “do not seek male partnership for anything besides sperm,” said Bondar. Does that makes them queer? To answer that question would be to anthropomorphize, which is either totally fine or a terrible idea, depending who you ask.

Question 3: Jerom in Dallas, TX asks:

“If the basis of a living fossil is that it’s genetic makeup hasn’t changed a whole lot over a couple thousand years, like alligators and such... forgive me if I’m wrong but humans haven’t changed a whole lot over a couple thousand years, so would we be considered human fossils or what are we?”

GirlOnAlligator.gif

First, Jerom? Jerome? Jerum? Sorry if we are getting your name wrong dude.

This term comes straight from Darwin himself in On the Origin of Species. He wrote that living fossils were creatures that are “a thin straggling branch springing from a fork low down in a tree, and which by some chance has been favoured and is still alive” and have “apparently been saved from fatal competition by having inhabited a protected station.” Which is to say, they emerged as a new species a long time ago, and have occupied a quiet little niche ever since. Horseshoe crabs, alligators, coelacanths, sharks have all been characterized as living fossils.

However, immediately the problem with this question is the lack of consensus over the definition of living fossil, as paleontology blogger Brian Switek has ranted. In fact, he points out that if we use Jerom/Jerum’s definition — which alludes to genetic make-up — then there are definitely no living fossils, since at the genetic level we are an absolute “riot” of change. But under a more lax definition, we are absolutely living fossils, since we exist in the fossil record, and we’re still around today.

So rather than trying to answer this question, I’m going to propose we switch to a more restrictive and easily defined definition of living fossil. Like the coelacanth and metasequoia, the term should only be used to describe species that we first discovered as a fossil, and only later realized were still alive. Boom. Easy.

(And by this standard we are not living fossils, which I think is the best indication that this is a better definition.)

Question 4: Katherine from Austin, TX asks:

“How much does it costs on average to ride on the elevator rather than taking the stairs. I was in a building in Austin, Texas it was just a two story building with a very very slow big elevator. And I thought, I wonder what it costs in terms of installing the elevator, maintenance and upkeep on the elevator and then just the energy to make it go up and down?”

elevator.gif

Ah, there is nothing more satisfyingly righteous than judging people for being slightly lazier than us. Even among the elevator-riders in our office (which, for the record, is on the sixth floor) there is judging.

“Are you really riding the elevator up to just the second floor?” *scoff*
“Are you riding the elevator down one floor to the basement?” *incredulous guffaw*
“Me? No, no, I’m going all the way to the sixth floor. That’s much different.”

So, yes, elevators use energy. How much energy they use depends entirely on the type of elevator, though and results vary widely. Want to nerd out? Find out the details of your elevator and enter them into this nifty calculator. I put in the details for our office's two 6-story elevators and found that each one uses somewhere around 4,600 KWh. To put that in context, that's about the same as what the electric hot water tank that you might have in your basement uses, which is to say not very much in the grand scheme of things.

What this really comes down to is the fact that elevators are actually a shockingly efficient means of conveyance. They run up and down a fixed, low-friction path, and when they rise up they are actually storing potential energy, which they can use again for the return trip down. And let’s not forget what elevators make possible: they make buildings handicap accessible, they make moving heavy furniture up and down floors less awful, and they provide time in which strangers can stand and have short awkward exchanges or eavesdrop on fragments of other people's’ conversations… valuable stuff! So I don’t think it’s fair to say we could get rid of elevators entirely, and save ourselves the "embodied energy" of building and installing the things.

Translation: if you’re looking to save energy, by all means take the stairs (and hey, you'll get some likely much-needed exercise!), but if you're looking to dole out shame on friends and co-workers in order to get them to change their behavior, there is lower hanging fruit. When Slate’s Nina Rastogi got this question back in 2009, she calculated you use less energy taking the elevator than is saved after four hours by switching from an incandescent to a CFL.

Now, if you want me to scoff at something, don’t get me started on those silly “vintage” lightbulbs, or people who think driving a hybrid car gives them an excuse to drive as much as they want.

Question 5: Kenneth from Penacook, NH asks:

“I’ve heard tale of some crazy people out there who ride their bike to work in sub-zero temperatures, and I’d like to ask Sam specifically: what would lead someone to do such a foolish thing?"

giphy (2).gif

Confession, I knew this question was coming… because Twitter, and because I talked about my bike commuting system on twitter. So you can take the shortcut and just read that thread, if you’d like. But just as a heads up, the trolls are in there too, and some of them are my co-workers. If you don’t like the social media, here’s the summary: I rode my bike to work when it was -18 degrees Fahrenheit and was bragging about it a little bit.

If you want to have something to brag about on Twitter, the challenge is to keep your hands, feet and face warm. For really cold days, I do have a couple of pieces of special equipment — Bar Mitts, neoprene shoe covers, and a couple of Buffs. You won’t look good (sorry, did I not mention that part earlier?) but you can totally equip yourself for less than the price of a couple tanks of gas. Apart from those items, all you need is to just wear a whole ton of layers. Put on all your clothes, one on top of the other and you should arrive at work toasty warm, if not a little sweaty.

BONUS ROUND... Sam Ruined It

sam-ruined-it.gif

Introducing a new segment on Ask Sam, idea courtesy of Outside/In contributor Cordelia Zars, in which Sam takes something that you think is a good thing, and lets you know that it's actually not that awesome!

Today on Sam Ruined It, Sam ruins hybrid cars for all of us.

Turns out, they're not really much better than your standard gas guzzlers.

Don't believe him? Just wait! Sam found this chart and helpfully circled two popular hybrid cars for you. The taller the bar, the more CO2 emissions over the life of your car. Which means that your Prius is barely better on the emissions front than your neighbor's diesel-powered Ford Focus. And the Prius is a top performer on the mileage front, get something a little bigger and suddenly you would have been better off just buying a gas-only Volvo. Oof. That one stings. 

TTW stands for "tank-to-wheels." That line will show you CO2 emissions produced by burning fuel in a vehicle. And the line representing WTT, "well-to-tank," is showing you the emissions produced over the life cycle of the fuel before it gets to your car, from its primary source to the point at which you get that fuel at the pump. Take-away: you don't get a pass for driving, no matter what you drive.

To the Nissan Leaf, Batman! 

Hybrid LCA.JPG
DebbieDowner.gif

Outside/In was produced this week by:

Outside/In was produced this week by Sam Evans-Brown with help from: Taylor Quimby, Maureen McMurray, Hannah McCarthy, Jimmy Gutierrez and Justine Paradis.

Special thanks to Nick Capodice, the one-man barbershop quartet who made our "Sam Ruined It" theme song.

The Ask Sam Theme is by Taylor Quimby.

The Outside/In Theme is by Breakmaster Cylinder.

If you’ve got a question for our Ask Sam hotline, give us a call! We’re always looking for rabbit holes to dive down into. Leave us a voicemail at: 1-844-GO-OTTER (844-466-8837). Don’t forget to leave a number so we can call you back.

Vultures Inherit The Earth

The Bicknell's Thrush is a bird that can only live in a few very very restricted places. It spends its summers in dense alpine forests in the Northeast of the US. In the winter, perhaps as many as 90 percent of the birds fly to the Dominican Republic. It's a bird without many options, and that makes it a poster child for what's to come. 

Featuring Chris Martin, Dave Anderson, Sam’s friend Stu, Chris Rimmer, Katie Fallon, Kirsti Carr, Nate Launer, Yolanda León, and Roman Julliard.

“Our bird”—that’s what conservationists in New England call the Bicknell’s Thrush. Why do they love it so much? It’s not a particularly comely bird. It’s almost entirely indistinguishable from the much more common gray-cheeked thrush. It has a nice song, but it’s about as endearing as any other song bird you might notice in the woods. What gets the Bicknell’s thrush its the moniker is simply that you can’t find it anywhere else.

“They’ve pigeon-holed themselves into a pretty narrow ecological niche,” says Chris Rimmer, director of executive director of the Vermont Center for Ecostudies, a little research and conservation outfit that has taken up the challenge of trying to study and conserve the thrush.
 
That ecological niche is so small it’s almost comical. In the summer, the birds stick to “thick stands of stunted conifers on steep mountain slopes or near tree-line” according to the researcher that successfully argued the bird should be considered its own species, back in 1993. That means we’re talking about a handful of weather-beaten, high mountain peaks in the northeast of the U.S. and Southern Quebec. In the winter, the birds fly south, and nearly all of them head to the same place. Rimmer says that somewhere around 90 percent of Bicknell’s thrushes spend the winter in wet forests in the interior of the Dominican Republic.

In other words, the Bicknell’s thrush is a specialist: on both ends of its range, it lives only in a very narrow band of habitats. They don’t seem to know how to live anywhere else. “If these habitats disappear from our mountain tops,” explains Rimmer, “I don’t think the birds are going to just find a different place to go.”
 
Consider, now, another bird, one nobody seems to call “our bird,” though it has its aficionados: The turkey vulture.
 
“I think turkey vultures are just about a perfect creature,” says Katie Fallon, author of Vulture: The Private Life of an Unloved Bird. “They breed from south central Canada, throughout most of North America, Central America, and all of South America. They’re even on islands... Caribbean Islands... the Falkland Islands. They’re a bird that can be seen by almost everyone in the hemisphere.”
 
Turkey vultures aren’t picky. They will nest in dark crevices, abandoned buildings, the nests of other birds, mammal burrows, and even quiet spots on the forest floor, if nothing else is available. They are also shockingly efficient. When soaring, their heart-rate is nearly the same as when they are sleeping, which has even led some to suggest turkey vultures might actually take quick naps while flying. This is just one of the many delightful facts about these birds—my personal favorite is that their stomachs are acidic enough that it can neutralize cholera, botulism and anthrax.

When you add these various evolutionary talents up, you get an animal that is poised for success in virtually any habitat; basically, you have a generalist on your hands.
 
The world is made up of many species, and any one of them will loosely either fit the profile of a generalist or a specialist. That has always been true. What is newly true is that species are disappearing at an alarming rate, and many scientists believe we’re seeing the beginnings of something that will eventually be recognized as a mass extinction event.

““If these habitats disappear from our mountain tops, I don’t think the birds are going to just find a different place to go.””

And the problem is that these extinctions are not distributed equally. They’re coming for the specialists first.
 
“There’s really a striking common pattern that specialist species are declining everywhere,” explains Romaine Julliard, a researcher with the National Museum for Natural History in Paris, who co-authored a paper on the subject with the striking sub-title: toward a global functional homogenization? He say he found the decline “in coral fish, marsupials in Australia, and bumblebees in the UK, and some plants.”
 
But what’s intriguing about the trend is that the decline of specialists is “almost balanced by the increase in population size of generalist species.” Julliard has studied European birds in particular, and he found that while the abundance of specialist birds has declined 20 percent, numbers of generalists has increased by 20 to 25 percent.
 
We see this in our tale of two birds as well. The Bicknell’s thrush is losing habitat at both ends of its range. The high, coniferous forests are retreating upslope towards oblivion as climate change warms the Northeast, and illegal agriculture has eaten into the national parks that serve as the bird’s refuge in the Dominican Republic. There are estimated to be around 100,000 of the birds in total, and the species is on several lists of birds that the conservation community is concerned about.

a baby turkey vulture in its nest

a baby turkey vulture in its nest

The turkey vulture—in contrast with the Bicknell’s thrush—is thriving. Roadkill on our highways has created what amounts to a massive network of turkey vulture smorgasbords, crisscrossing the nation. Because the black asphalt absorbs and re-radiates heat during the day, these serpentine buffets also act as a ready source of thermal updrafts for the birds to surf along, spreading their ever-growing population to every nook and cranny of the hemisphere. Fallon says that 25 years ago the birds were estimated to number around 5 million, but today that number has risen to nearly 20 million worldwide.
 
This is the current trajectory we are on: The beautiful finely tuned specialists, hyper-efficient little motors built to extract calories from their own very, very specific habitats, are on the way out. As they vanish, the generalists—admittedly, marvels of flexibility and adaptation in their own right—are ascendant, rising to fill the space that’s left behind.

What’s behind this shift? According to Julliard, to date, it’s just regular old habitat loss. “Even though the climate change footprint on pressure on biodiversity is increasing and the evidence for that is increasing, it’s still likely lower than habitat degradation,” he says. In fact, a paper on extinction risk that was published in the most recent Proceedings of the National Academy of the Sciences came to the same conclusion: Large animals are most at risk from us eating them, small animals are at risk because we are destroying the places they live.

“We already see the same starlings and house sparrows in almost any city anywhere in the world. Could we get to a future where the skies are full of nothing but turkey vultures, and the oceans are populated entirely by jellyfish? ”

sam evans-brown thrush-listening, with little luck

Is there anything wrong with this push toward functional homogenization? We already see the same starlings and house sparrows in almost any city anywhere in the world. Could we get to a future where the skies are full of nothing but turkey vultures, and the oceans are populated entirely by jellyfish? To me that feels like a nightmare scenario—something from Margaret Atwood’s Maddaddam trilogy, except minus the genetic engineering.
 
Julliard has a reminder for me: “Evolution is really a force that drives to specialization and to differentiation,” he says. Pointing out that just as soon as we stop doing all the things that make life hard on them, the specialists will start to thrive again, and given enough time, speciation of new specialists will start to pick up again.
 
This reassurance is thanks to one of the tenets of ecological niche theory: In a stable habitat, natural selection favors the specialist. Which means “you need really a very high pressure to maintain this homogenization,” he says.
 
The problem, of course, is that the time-scales involved are deeply out of whack with our human experience. The world can recover from a whole heck of a lot, but that can take millions of years, and the world we’ll inhabit in the meantime will be a deeply impoverished one in comparison. And more to the point, who knows if we’ll even be around to watch the birds that repopulate that sky, to call them our own.

 

Outside/In was produced this week by:

Outside/In was produced this week by Sam Evans-Brown with help from: Maureen McMurray, Taylor Quimby, Hannah McCarthy,  and Jimmy Gutierrez.

Music from this week’s episode came from Blue Dot Sessions, Poddington Bear, David Szesztay, Jason Leonard and Ikimashoo Aoi.

Our theme music is by Breakmaster Cylinder.

If you’ve got a question for our Ask Sam hotline, give us a call! We’re always looking for rabbit holes to dive down into. Leave us a voicemail at: 1-844-GO-OTTER (844-466-8837). Don’t forget to leave a number so we can call you back.

Audio Transcript: Vultures inherit the earth

Note: Episodes of Outside/In are made as pieces of audio, and some context and nuance may be lost on the page. Transcripts are generated using a combination of speech recognition software and human transcribers, and may contain errors.

Sam Evans-Brown: [00:00:04] Do you hear any birds now?

Sam Evans-Brown: [00:00:15] Recently I went on two expeditions looking for birds. The first was with a friend of mine, Stu, on the side of New Hampshire's biggest, most famous rock pile, Mount Washington.

Sam Evans-Brown: [00:00:27] It's almost like snipe hunting.

Stu: [00:00:28] Yeah.

Sam Evans-Brown: [00:00:29] We're [00:00:30] going snipe hunting.

Stu: [00:00:32] We're looking for Little Foot, cousin of Bigfoot.

Sam Evans-Brown: [00:00:36] Spot number two, a much smaller hill with two friends of the show, Dave Anderson and Chris Martin, hosts of NHPR's long running nature facts podcast, Something Wild.

Dave Anderson: [00:00:47] These birds live in a stone fortress of granite.

Chris Martin: [00:00:50] Or big hollow logs. That's another place they might know.

Dave Anderson: [00:00:53] Abandoned buildings.

Chris Martin: [00:00:54] Old abandoned buildings in the woods.

Dave Anderson: [00:00:56] And rocky den sites like this.

Sam Evans-Brown: [00:00:58] In the first case on [00:01:00] Mount Washington with Stu.

Stu: [00:01:01] This is great.

Sam Evans-Brown: [00:01:02] We're looking for the Bicknell's thrush.

Stu: [00:01:03] Love the sound of birds in the night.

Sam Evans-Brown: [00:01:05] Yeah. A small, unremarkable songbird. Brown on top, gray with little spots on the belly. In the summer, it's only found in high elevation forests in the northeastern US and southeastern Canada, and there's only about 100,000 of them total. In the second expedition on the little rocky hill with Dave and Chris. We're looking for one of the Western hemisphere's most ubiquitous birds, the turkey vulture.

Dave Anderson: [00:01:29] If they feel trapped, [00:01:30] they will regurgitate on you.

Chris Martin: [00:01:32] Cool.

Dave Anderson: [00:01:33] They hiss. They have a naked head.

Chris Martin: [00:01:35] Do they hiss first?

Dave Anderson: [00:01:36] We'll find out.

Chris Martin: [00:01:37] Okay.

Sam Evans-Brown: [00:01:38] That's why I brought my sunglasses.

Sam Evans-Brown: [00:01:40] Supposedly, Dave knows where one of these majestic scavengers is nesting up on Mount Washington with Stu, as you heard --

Stu: [00:01:48] No.

Sam Evans-Brown: [00:01:48] We struck out, but down lower with Chris and Dave looking for the turkey vulture.

Dave Anderson: [00:01:55] There he is. Whoa! So right now [00:02:00] my adrenaline is redlined. That just scared the crap out of me.

Sam Evans-Brown: [00:02:04] After scrambling up the rocky slope, we spooked a fully grown turkey vulture. Six feet of silent black wings, a wrinkly, bald pink head out of its nest, a she or he spent the next 15 minutes flying in high, lazy circles above us.

Chris Martin: [00:02:22] The other one is probably out gathering food right now. I wouldn't expect it to be in here guarding the young. If there are young, which [00:02:30] I should be.

Sam Evans-Brown: [00:02:31] Would they be eggs or chicks?

Chris Martin: [00:02:32] There could be eggs. But at this time of year, June, they're probably chicks. But it's hard to say until somebody takes a look.

Dave Anderson: [00:02:38] 1 or 2.

Chris Martin: [00:02:39] Can we go closer?

Dave Anderson: [00:02:41] Oh, we're going in.

Chris Martin: [00:02:41] I'm going closer.

Dave Anderson: [00:02:43] I'll follow.

Sam Evans-Brown: [00:02:44] The nest is not really a nest. It's just a crevice in a field of boulders. And actually, what Chris and Dave did was send in the guy with the microphone first.

Sam Evans-Brown: [00:02:56] The entrance was too small to stand or to crouch, so I had to sort [00:03:00] of slither in on my belly.

Sam Evans-Brown: [00:03:02] Oh my gosh.

Sam Evans-Brown: [00:03:03] By the way, we cleared this with Chris, who is a biologist with the Audubon Society.

Sam Evans-Brown: [00:03:07] So how Chris, how close can I get before I'm being problematic?

Sam Evans-Brown: [00:03:11] And right there, just a few feet from the entrance, two fluffy little turkey vulture chicks.

Sam Evans-Brown: [00:03:19] Oh my gosh, they're tiny.

Sam Evans-Brown: [00:03:28] So two [00:03:30] bird chasing excursions, one for the rare and difficult to spot Bicknell's thrush, which ended in failure. The second, poking around in craggy corners for turkey vultures: a success. These two birds, the turkey vultures that we found, and the Bicknell's thrush that we didn't, they're representative of a trend that's underway right under your nose.

Katie Fallon: [00:03:55] Oh, I think turkey vultures are just about a perfect creature. They are a bird [00:04:00] that can be seen by almost everyone in the hemisphere.

Chris Rimmer: [00:04:04] The Bicknell's pigeonhole themselves into a pretty narrow ecological niche. And if these habitats disappear from our mountaintops, I don't think the birds are going to just find a different place to go.

Sam Evans-Brown: [00:04:28] This is Outside/In, a show [00:04:30] about the natural world and how we use it. I'm Sam Evans-Brown. Today, it's the tale of two birds, one the turkey vulture, almost universally reviled, but they're also pretty amazing in their own way. The other, the Bicknell's thrush, is a local celebrity, the target of research dollars and enthusiastic birdwatchers. But it's in a tight spot, literally and figuratively. And the story of these two birds actually tells us the story about our world [00:05:00] as a whole. It tells us where we're headed toward a world of songbirds and high alpine gardens, or toward a world in which turkey vultures inherit the Earth.

Sam Evans-Brown: [00:05:25] Okay. Right here at the top, I want to introduce you to an idea. You know how natural selection works. [00:05:30] Random mutations make individuals that are slightly different, slightly more able to succeed. All that. Now, one thing this does is the longer a species hangs out in a specific place, the better and better it gets at living in that place. They become really incredibly good at finding food and surviving much better than species that range more widely and live in many different places. This is called specialization, and as long as habitats are not [00:06:00] changing very much, it's the logical conclusion of natural selection. So now that you know that natural selection drives toward specialization, let's take a look at the Bicknell's thrush, starting with the guy who discovered it.

Chris Rimmer: [00:06:17] On June 15th, 1881. Believe it or not, I know the exact date.

Sam Evans-Brown: [00:06:22] That's wildlife biologist Chris Rimmer. He's basically the world's expert on these birds.

Chris Rimmer: [00:06:27] An amateur ornithologist named Eugene [00:06:30] P. Bicknell was hiking around on Slide Mountain in the Catskills of New York.

Sam Evans-Brown: [00:06:37] Hiking around and sees a bird that he doesn't recognize. It's a thrush that he doesn't recognize, and that was unusual for him.

Chris Rimmer: [00:06:44] So, as ornithologists did in those days, he pulled out his shotgun.

Sam Evans-Brown: [00:06:49] And he collected the bird. Just in case you didn't know this Audubon, like James Audubon that the bird society was named for, also [00:07:00] shot a ton of birds. Bicknell shot two of them and picked them up.

Chris Rimmer: [00:07:05] Examined them in his hand, still didn't recognize him, and thereupon sent them down to the Smithsonian, where they were identified as a new subspecies, or race of the gray cheeked thrush, which is a much more northern and widely distributed bird.

Sam Evans-Brown: [00:07:22] Case closed. Right? Well, fast forward 100 years. In [00:07:30] the 1990s, along comes this Canadian biologist.

Chris Rimmer: [00:07:33] A taxonomist zoogeographer named Henri Ouelett. He worked for the National Museum of Canada in Ottawa.

Sam Evans-Brown: [00:07:39] Something about the Bicknell's gray cheeked thrush thing didn't quite sit right with him, so he gets to work.

Chris Rimmer: [00:07:46] So he examined specimens in museums, finds.

Sam Evans-Brown: [00:07:50] Very slight differences in the feathers and body sizes. He then listens to them singing.

Chris Rimmer: [00:07:56] The songs of the two species, which are slightly different.

Sam Evans-Brown: [00:07:59] And if you played the song [00:08:00] of the one species. So that the other could hear it, they just didn't react. Which is weird.

Chris Rimmer: [00:08:11] Because if you play the song of a, let's say, a song sparrow or a robin to another robin, usually they're going to react because they think there's an intruder on their territory. They got to drive it out, right?

Sam Evans-Brown: [00:08:22] And then comes the most important bit of evidence.

Chris Rimmer: [00:08:25] The final nail in the coffin.

Sam Evans-Brown: [00:08:27] He tested their DNA and found that they were different enough [00:08:30] that probably the two species stopped breeding together around a million years ago. So he writes all this up in a paper, brings it to the authorities.

Chris Rimmer: [00:08:39] The sort of god squad of ornithological taxonomy, the American Ornithologists Union Checklist Committee, and they accepted it. And so in 1995 the switch was made. Bicknell's went from being a subspecies of gray cheek to being [00:09:00] its own distinct species.

Sam Evans-Brown: [00:09:06] Let me just be clear about what this is. This is a small population of birds that a million years ago, started living further south than its former compatriots because they've now become separated. The two populations stop breeding with each other. But this happened relatively recently in evolutionary terms, so there haven't been enough random mutations [00:09:30] to make them actually look different.

Chris Rimmer: [00:09:32] You can't tell them apart. People say they can. I don't believe it.

Sam Evans-Brown: [00:09:35] But science tells us they're different enough to be a new species, though. A new species that is almost indistinguishable from the old one. And there is nothing that birders love more than a new species.

Nate Launer: [00:09:46] So we're doing a 20 minute surveys at each point.

Sam Evans-Brown: [00:09:50] This means people care enough about them to design a study to keep track of them, called Mountain Birdwatch.

Nate Launer: [00:09:57] And I can still hear that Winter Wren. He's really far away.

Sam Evans-Brown: [00:09:59] And [00:10:00] that's why we're on the side of Mount Washington at the beginning of the story. Every year, a bunch of volunteers and a few college students paid by Chris Rimmer's organization, the Vermont Center for Ecostudies, go up and very carefully, very scientifically count birds. That first one you heard was Nate Launer. And here's another Kirsti Carr.

Kirsti Carr: [00:10:20] What I think is so cool is that it's endemic to the northeast and...

Sam Evans-Brown: [00:10:26] It's like, it's our bird.

Kirsti Carr: [00:10:28] It's our bird, and it's, you [00:10:30] know, it's globally rare and it travels all the way down to the Caribbean area, you know, to like the island of Hispaniola, I guess, is a place where it overwinters the most.

Sam Evans-Brown: [00:10:48] So, you see, in the summer when they're breeding, Bicknell's thrush only lives in high altitude forests in the northeast of the US and the southeast of Canada. And then in the winter, they fly south. And some [00:11:00] crazy number, maybe as much as 90% of them spend the winter on Hispaniola. Mostly in the Dominican Republic. Just think how crazy that is. There are lots of big islands down there Cuba, Puerto Rico, Jamaica. But the thrushes are picky and the vast majority of them go to this one 30,000 square mile island. This bird is a specialist. It can survive in just one kind of habitat. [00:11:30] There are lots of specialists out there. Koalas, for example, can only eat eucalyptus leaves. Piping plovers can only nest on sparsely vegetated beaches. The monarch butterfly caterpillar can only feed on milkweed leaves. The Bicknell's thrush is like those more famous specialists. The Cornell Lab of Ornithology says it has one of the most restricted breeding and wintering ranges of any North American bird. If anything goes wrong in the places it lives, it's got [00:12:00] nowhere else to go. Now, in contrast, allow me to reintroduce you to:

Katie Fallon: [00:12:14] Turkey vultures are just amazing in that they can eat disease and neutralize it.

Sam Evans-Brown: [00:12:21] The turkey vulture.

Katie Fallon: [00:12:25] Turkey vultures can eat things like an animal that has died from anthrax. [00:12:30] They can also eat an animal that's died of botulism toxin or cholera. The turkey vulture can eat it, and it doesn't affect the turkey vulture in any negative way.

Sam Evans-Brown: [00:12:41] Our turkey vulture enthusiasts, by the by, is Katie Fallon, who wrote Vulture: The Private Life of an Unloved Bird.

Katie Fallon: [00:12:48] I actually went, had a few other possible subtitles for the book. One was Vulture: Eat Your Heart Out and another one was Vulture: Happy Entrails to you.

Sam Evans-Brown: [00:12:59] Oh man. [00:13:00]

Sam Evans-Brown: [00:13:01] The crux of Katie's book is that turkey vultures deserve some cred here for cleaning up after us.

Katie Fallon: [00:13:07] We unfortunately aren't as fond of these birds as I think we should be because of the great service they provide.

Sam Evans-Brown: [00:13:13] Most of what makes turkey vultures so amazing is how incredibly well adapted to eating dead things they are. But since that's gross, I'm going to intersperse gross but cool turkey vulture facts with some straight up cool turkey vulture facts here. So [00:13:30] turkey vulture stomach acid is roughly ten times more acidic than human stomach acid, which means by the time it gets to the other end, their waste is both clean and very acidic. So as a strategy, they deposit it all over their legs.

Katie Fallon: [00:13:47] That helps cool them off if it's hot. But we also think that that liquid waste acts as a sanitizer and it kills bacteria that might be on their feet from standing on a carcass. So it's sort of like they carry [00:14:00] their hand sanitizer with them, right?

Sam Evans-Brown: [00:14:03] Gross. But cool. Straight up cool. You know how you see them soaring all the time, lazily tipping their wings back and forth in the hot air?

Katie Fallon: [00:14:14] Yeah, they can soar for a long period of time. They've done some studies where they've put implants in Turkey vultures to monitor their heart rate and their respiration rates, and they found that when a turkey vulture is soaring, it's it's [00:14:30] a heart rate is about the same as when it's asleep.

Sam Evans-Brown: [00:14:35] That's amazing!.

Katie Fallon: [00:14:36] Pretty amazing!

Sam Evans-Brown: [00:14:37] Yeah! My heart rate goes up if if I'm sitting in a chair versus lying in a bed.

Sam Evans-Brown: [00:14:41] Okay, okay, okay. Just a couple more. Gross/Cool: Turkey vulture heads are bald so they won't get rotting meat chunks stuck to feathers when they're jamming them into carcasses. Regular old cool: Even though most birds can't really smell at all. Turkey vultures noses are so good that in one case study, a bunch of farmers were shooting and burying ground hogs, only [00:15:00] to find them dug up and eaten the next day.

Katie Fallon: [00:15:02] They have documented them being able to smell something like a dead rat underneath leaves in a forest, and they've also documented turkey vultures actually digging up carcasses that have been intentionally buried.

Sam Evans-Brown: [00:15:15] And all of these various evolutionary talents add up to an extremely successful bird.

Katie Fallon: [00:15:22] They breed from south-central Canada throughout most of North America, Central America, and all [00:15:30] of South America. They're even on islands. Caribbean islands. The Falkland Islands has turkey vultures. They are a bird that can be seen by almost everyone in the hemisphere. Oh, I think turkey vultures are just about a perfect creature.

Sam Evans-Brown: [00:15:54] So, they're like an amazing generalist.

Katie Fallon: [00:15:56] Yes they are, they are an amazing generalist. Exactly.

Sam Evans-Brown: [00:16:02] A [00:16:00] generalist. They're thriving everywhere. They can nest in a rocky talus slope or in an abandoned warehouse. They don't need a very specific set of ecological conditions in order to survive. They take what they've got and they work with it. There are lots of these cockroaches, rats, ravens, raccoons and jellyfish. Quite often, generalists do a good job living alongside humans. [00:16:30] I mean, if you think about it, we're really the most obvious example of a generalist. So we've got one very rare bird that needs a very specific habitat to survive, and another that can live almost everywhere. Now, you've probably heard this part of the story already. Species are disappearing. Many scientists believe we're in the midst of something that will eventually be recognized [00:17:00] as a mass extinction event. And those extinctions, they're coming for the specialists first.

Roman Julliard: [00:17:07] Yeah. So I'm Roman Julliard. I'm working at the National Museum for Natural History in Paris.

Sam Evans-Brown: [00:17:14] This is Roman Julliard, who came up with a way to mathematically define what a specialist species is.

Roman Julliard: [00:17:20] Since the beginning of our survey, which is now 25 years old, that's on average special species population size [00:17:30] have decreased by 20%.

Sam Evans-Brown: [00:17:32] But this is the story you've heard already. The other half of the story is that specialists are being replaced by generalists.

Roman Julliard: [00:17:41] And it's almost balanced by the increase in population size of generalist species.

Sam Evans-Brown: [00:17:47] Almost balanced. So while specialists are declining, generalist species are growing. Now, Roman studies birds. And we have been talking about birds. But this is not just a bird [00:18:00] thing.

Roman Julliard: [00:18:00] There's really a striking common pattern that specialist species are declining in everywhere.

Sam Evans-Brown: [00:18:06] So all around the world.

Roman Julliard: [00:18:08] And it was true in coral fish, marsupials in Australia...

Sam Evans-Brown: [00:18:15] The Bicknell's thrushes and species like them...

Roman Julliard: [00:18:17] And bumblebees in, in the UK and...

Sam Evans-Brown: [00:18:20] ...are struggling.

Roman Julliard: [00:18:21] Yeah and some plants also.

Sam Evans-Brown: [00:18:23] And the turkey vultures, the generalists, are doing better. They're actually getting more numerous. [00:18:30] Just one particularly terrifying example. A few years ago, the first study ever to try to estimate global jellyfish populations came out, and it found that in 60% of the world's oceans, jellies are on the rise. The headlines that followed jellyfish are taking over the oceans. We're headed toward a jellyfish world. What's [00:19:00] the deal? Well, it's really not a surprise.

Roman Julliard: [00:19:04] Well, it's most likely a habitat degradation. I mean, it's the most parsimonious explanation.

Sam Evans-Brown: [00:19:13] The most parsimonious explanation. If you only know how to live in one place, and that place is changing because of logging or invasive plants or increased forest fires, or not enough forest fires or whatever the problem is locally, you're in a tough spot. And that's the story with our bird, too. [00:19:30]

Yolanda León: [00:19:30] No matter how much it's done in North America, if in the wintering range and there there are no, no changes, it's it's it's a bottleneck.

Sam Evans-Brown: [00:19:42] This is Yolanda León, executive director of Grupo Jaragua, a conservation organization down in the Dominican Republic. While we snooty New Englanders think of the Bicknell's thrush as our bird, it spends half the year in the Caribbean, too. Nearly all of the population spends the winter [00:20:00] on a single island, and a lot of them are in a single place right now.

Yolanda León: [00:20:05] Most of the habitat for many of these mountain birds and other species is in Sierra de Bahoruco.

Sam Evans-Brown: [00:20:13] The Sierra de Bahoruco is a mountain range on the border with Haiti. It's also a national park, the biggest in the Dominican Republic.

Yolanda León: [00:20:20] And you would think because it's a national park, it's it's protected and the birds are safe there. However, [00:20:30] what we found out was that there was a lot of agriculture going on inside the park. This is all illegal agriculture.

Sam Evans-Brown: [00:20:39] This is what's called a paper park. The government declared it off limits, but its borders aren't marked or enforced. So over time, people have started to cut down trees and grow crops. In particular, wealthy farmers have started to grow avocados.

Yolanda León: [00:20:54] And these are export avocados.

Sam Evans-Brown: [00:20:56] So this is like this is like Chipotle, you know, [00:21:00] all the, all the guacamole that we love.

Yolanda León: [00:21:03] Yes, yes. And you know I love avocados, ad people say, it's like: you're opposed to avocado! I love avocado, but avocados don't have to be produced in a national park.

Sam Evans-Brown: [00:21:14] A quick aside: apparently most of the Dominican Republic's avocados go to Europe, not to Chipotle. And let me just put a big old disclaimer here. National parks in developing economies is a complicated, fraught topic. Some subsistence farmers actually work in this park and [00:21:30] had it declared right on top of them. And others are folks who genuinely didn't know the park was here because, you know, it's just on paper.

Yolanda León: [00:21:37] Like, with the avocado and the farming, there are big players and small players, and I think chasing after the small players, the poorest people is not the best solution. And it's not it's not very fair.

Sam Evans-Brown: [00:21:50] But after all caveats about the problems with how Western-style conservation is executed in the developing world, it's pretty easy to recognize that this isn't a good situation [00:22:00] for our bird.

Yolanda León: [00:22:01] On the north side of Bahoruco, we do have a good area that seems to be off limits because of of road access, and I think that area is pretty safe. But on the south side of Bahoruco, if nothing is done in the next 2 to 5 years and we, we are not going to have any more of the the birds or any of its fauna.

Sam Evans-Brown: [00:22:33] Habitat [00:22:30] degradation a specialist's worst nightmare. And it's happening up on the north end of their range, too.

Chris Rimmer: [00:22:40] Yeah, it's absolutely it's one of the most vulnerable habitat types in the northeast.

Sam Evans-Brown: [00:22:46] Here's Chris Rimmer again. Remember, in the summer, Bicknell's thrush live in a specific type of forest up on the sides and tops of mountains.

Chris Rimmer: [00:22:56] These forests are predicted to begin getting [00:23:00] pushed up slope by warming temperatures. And if these habitats disappear from our mountain tops, I don't think the birds are going to just find a different place to go. They've pigeonholed themselves into a pretty narrow ecological niche.

Sam Evans-Brown: [00:23:13] Meanwhile, turkey vultures, they're thriving.

Katie Fallon: [00:23:16] 25 years ago, we thought there were about 5 million turkey vultures.

Sam Evans-Brown: [00:23:21] Since then, we've made more roads which mean more roadkill and also more hot air updrafts to surf along. There's also less shooting [00:23:30] and poisoning of vultures going on, and warmer winters probably are better for them, too. Less frozen meat. So today -

Katie Fallon: [00:23:38] And the most recent estimates that I've read are, you know, we might have as many as 20 million turkey vultures worldwide.

Sam Evans-Brown: [00:23:51] This is the trajectory we're on. The beautiful, finely tuned specialists. Hyper efficient little motors built to extract [00:24:00] calories from their own very, very specific habitats are on their way out. And as they vanish, the perhaps equally beautiful in their own way, generalists are rising to fill the space that's left behind. You can already see the same starlings and house sparrows and pigeons, and almost any city anywhere in the world. In my mind, there's this nightmare scenario where the skies [00:24:30] are full of nothing but turkey vultures. The forests and the cities are full of skunks and raccoons, and the oceans are populated entirely by jellyfish. It's the stuff of dystopian novels. It's the jellyfish world.

Roman Julliard: [00:24:54] So I don't think we'll I mean, we really need to work hard [00:25:00] to have the nightmare scenario.

Sam Evans-Brown: [00:25:03] Ah. A reminder from Roman Julliard. Remember where specialization comes from. In stable environments, specialists actually do better than generalists.

Roman Julliard: [00:25:13] You need really a very high pressure to maintain these homogenization.

Sam Evans-Brown: [00:25:17] Specialists are just better than generalists at getting food in their very special niche.

Roman Julliard: [00:25:22] If you relax a bit, evolution is really a force that drives to specialization in a differentiation. [00:25:30]

Sam Evans-Brown: [00:25:30] So if we stop doing all the things that we're doing that make life hard on them and the habitats stabilize, the specialists will start to thrive again. And given enough time, we'll even get new specialist species. The problem today is environments are changing faster than evolution can change the animals. Really, if you set your frame of reference long enough, thousands of years, even millions of years, there's very little that the earth can't [00:26:00] recover from.

Roman Julliard: [00:26:01] So I think we I mean, we should still be optimistic, and, uh...

Sam Evans-Brown: [00:26:05] So, so are you. Are you optimistic then?

Roman Julliard: [00:26:11] There's no objective reason to be optimistic because the the pattern is still the decrease wherever you look at. But it's still reversible. That's the, the point.

Sam Evans-Brown: [00:26:24] That was a very scientific answer.

Roman Julliard: [00:26:25] Yeah.

Sam Evans-Brown: [00:26:39] No [00:26:30] objective reason to be optimistic, but maybe we should try anyway. Pretty much my motto going through life. Outside/I [00:27:00]n was produced this week by me, Sam Evans-Brown, with help from Hannah McCarthy, Taylor Quimby, Jimmy Gutierrez, Ben Henry, and Maureen McMurray. Music from this week's episode came to us from oaddington Bear, Blue Dot Sessions, David Zest, Jason Leonard, and Ikimasoo Aoi. If you've got a second, head online to check out our website [00:27:30] outsideinradio.org. We've got photos of the tiny turkey vulture chicks and the crevice that I had to crawl into in order to see them. We'll be posting them on social media too @Outsideinradio. Our theme music is by Breakmaster Cylinder. Outside/In is a production of New Hampshire Public Radio.

In Too Deep

This week, we're bringing you an adventure from our friends at the Outside Podcast. Trapped in a shipwreck on the ocean floor, running out of oxygen, body temperature falling, how long could you survive? Intrepid producers Robbie Carver and Peter Frick-Wright take a deep dive on this one.

In 1991, a man named Michael Proudfoot was SCUBA diving off the coast of Baja, Mexico. The details of his story are everywhere. And, more or less, the same. Exploring a shipwreck, Proudfoot breaks his regulator and surfaces in an air pocket deep in the belly of the ship. He finds a tea-kettle full of fresh water, and eats sea urchins to survive. But as producers of the Outside Podcast— Robbie Carver and Peter Frick-Wright — dig deeper and deeper into the tale, it becomes harder and harder to tell what's real and what isn't.

This is a story about deep-sea fact checking. Fact checking to the point of no return. What happens when you can't prove a story -- a really great, big fish of a story -- right or wrong?

Outside/In was produced this week by:

Outside/In was produced this week by Sam Evans-Brown with help from: Taylor Quimby, Hannah McCarthy,  and Jimmy Gutierrez.

Special thanks to Robbie Carver and Peter Frick-Wright for sharing their reporting and story from the Outside Podcast. You can hear more here.

Our theme music is by Breakmaster Cylinder.

If you’ve got a question for our Ask Sam hotline, give us a call! We’re always looking for rabbit holes to dive down into. Leave us a voicemail at: 1-844-GO-OTTER (844-466-8837). Don’t forget to leave a number so we can call you back.