MADDIE SOFIA, HOST:
You're listening to SHORT WAVE from NPR.
EMILY KWONG, HOST:
Hey, everybody. Emily Kwong here.
SOFIA: And Maddie Sofia.
KWONG: There's a lot going on this time of year. But first of all, shoutout to my fellow Asians celebrating Lunar New Year.
SOFIA: Woop woop (ph). Happy New Year.
KWONG: And also this weekend, some of you may be celebrating Valentine's Day. And I thought we could celebrate with a little Valentine's Day fact exchange - a gift exchange but with facts.
SOFIA: Yes, there is nothing more romantic than scientific facts. People are saying that all the time, Kwong.
KWONG: Yeah. And to stick with the Valentine's Day theme, I brought Maddie some facts about chocolate, as much a masterpiece of farming as it is fermentation.
SOFIA: And I have some facts about courtship in the animal kingdom, moves that make our human game honestly look kind of weak.
KWONG: So today on the show, a love-filled fact exchange between me and Maddie.
SOFIA: This is SHORT WAVE, the daily science lovecast from NPR.
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SOFIA: All right, Emily Kwong. Lay some of that chocolatey goodness on me.
KWONG: You got it because chocolate is the true meaning of Valentine's Day.
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UNIDENTIFIED PERSON: Only a chocolate this pure can be this silky.
SOFIA: Kwong, you know I love you, but I'm lactose intolerant. Why are you doing this to me?
KWONG: Maddie, I thought about this. The thing that gives chocolate its flavor is dairy-free.
SOFIA: (Laughter) OK.
KWONG: Did you know cocoa comes from a fruit that grows these amazing-looking, multicolored cacao pods?
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DARIN ASHRAM SUKHA: And I would see these red things hanging from the trees and thinking, wow, what are these things?
KWONG: This is food scientist Darin Ashram Sukha at the Cocoa Research Centre at the University of the West Indies, speaking with Simran Sethi and our friends at Life Kit about his fascination with cacao pods.
SUKHA: It's, like, a football-shaped fruit. It can be smooth. It can be warty. It can have ridges.
KWONG: Darin saw these pods all over the place growing up in Trinidad and Tobago. They grow on the cacao tree, or Theobroma cacao, an understory crop of the tropical rainforest, meaning they grow pretty close to the ground. And the exterior of these pods is hard. Like, it's tough but not so tough that critters can't break it open.
SOFIA: To go on a little cacao binge.
KWONG: Correct. If I was a squirrel, this would be what I would do.
SOFIA: I mean, absolutely.
KWONG: Darin breaks open a pod with a special tool, kind of like a dull machete.
SUKHA: It resists, but it gives at the same time. But it feels very satisfying. And then when you twist the blade, you hear a sort of crunch, and you see it opening inside.
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KWONG: Darin describes the inside of the pod like a sticky cobweb. It has rows of cacao seeds, which he calls beans, covered in this gummy, white pulp called mucilage.
SOFIA: Delicious - mucilage.
KWONG: And the aroma hits immediately.
SUKHA: I'm smelling my own now. And it smells citrusy, like citrus flowers. It's like a subtle perfume.
KWONG: Yeah. There's so much flavor potential in these caco beans at this point. Once the pod is opened, fermentation begins. So after the seeds are removed from the pod, they're collected and transported to an area where they can ferment for days.
KWONG: Yeah. And naturally occurring microbes break down those beans and unlock their flavor notes.
SOFIA: I did not know that, Kwong. I mean, fermentation - got to love it. It kind of sounds like wine a little bit - maybe a little bit.
KWONG: Yeah, kind of, if you think of cacao beans like grapes. And the taste does reflect the ecosystem from which it came. The beans are then sorted, roasted and sold to chocolate makers to become the chocolate you know and love.
SUKHA: It can be fruity. It can be floral. It can be bright. So I like to think of the flavor profile that cocoa offers to be like a good piece of music. The same way what makes a good piece of chocolate is a harmonious presentation of flavor notes that are in balance with each other.
KWONG: At the Cocoa Research Centre, he works on the level of genetics and with farmers, too, optimizing flavor and adapting their crops to climate change and disease. Darin even works with a cacao farm he used to pass as a child. Chocolate is something he just can't stay away from.
SUKHA: It's like "Hotel California." You can check out anytime you want, but you can never really leave. It gets under your skin, and it becomes part of your consciousness. So for me, I don't really work at a job. I work at a passion.
SOFIA: Emily Kwong, somebody more passionate about chocolate than you. Can you believe?
KWONG: It's a dream.
SOFIA: (Laughter). OK, Emily, thank you for those wonderful chocolate facts. I liked the mucilage part and the fermentation part best.
KWONG: I knew you would. I put that in there for you.
SOFIA: OK. Are you ready to talk critter courtship?
KWONG: I am ready because we always talk about the art of seduction - is how it's described, right? But what about the science of seduction?
SOFIA: Well, you know, seduction is kind of a human word. And it might be a little strong for some of these behaviors, but yeah. Yeah, yeah, yeah. Let's start with one animal that is known for its powers of seduction, the scorpion.
KWONG: Oh, my - of course, you put in arachnid in here. Ridiculous. You just did a spider episode, like, two weeks ago.
LAUREN ESPOSITO: Scorpions are, like, the fine ballroom dancers of the arachnid world. Like, some other spiders are, like, crazy and energetic and doing, like, disco situation. Scorpions are refined. They just do a ballroom style.
SOFIA: That's Lauren Esposito. She is a curator of arachnology at the California Academy of Sciences and the creator of 500 Queer Scientists, which we love.
KWONG: And repeat - scorpions dance?
SOFIA: Yeah, that's what they call it. But, you know, first, they have to find each other, right? They have to get to the dance floor. Now, some of this is done through pheromones, little chemicals animals release that can be, you know, picked up by other animals. And on top of that, in some species, the males start to do this thing called juddering, which I like to think of as a little, like, warm-up to the real dance. They basically just start shaking their tiny scorpion bodies as fast as they can.
ESPOSITO: The really cool thing about most arachnids is they have these structures called slit sensilla in their feet that allow them to hear vibrations through the ground. So, like, because it's this really sharp, drastic shaking, it probably sends a pretty unique signal that's like, hey, lady. I see you're looking for love. Please don't eat me. Are you interested?
KWONG: Don't eat me?
SOFIA: Yeah, yeah. You know, depending on the species, there is some light to heavy cannibalism in the scorpion world. So in some cases, he's really taking his life into his little claws during this courtship.
KWONG: This sounds terrifying. I had no idea.
SOFIA: (Laughter) But no, no, no. It's nice. It's nice. Once everybody is happy, at this point, the dance begins. They face each other, and they kind of grab pinchers.
ESPOSITO: And then he begins by sort of, like, pushing her backwards and then pulling her forwards, really like leading her in this, like, back-and-forth promenade a deux, as it's called in the literature.
KWONG: Did she just say promenade a deux?
SOFIA: Yeah. Yep. Scorpions are refined.
ESPOSITO: And they continue on this promenade. And the promenade can last for just a few minutes. And the female can break it off either by ripping her hands away from his grasp or just by, like, eating him.
KWONG: Eating him - so refined.
ESPOSITO: As they continue this courtship dance, like, things start to progress. It doesn't just consist of, like, the simple back-and-forth steps. It's more complex than that. Like, these animals are really serious about their dancing. And the next stage that it can progress to is something called cheliceral massage.
SOFIA: Now, hang with me. Chelicerae are the name of scorpion mouthparts. So in some species, he rubs his little mouthparts on hers during courtship - a little kiss, if you will.
SOFIA: And, Kwong, there are even more moves that we don't even have time for. I mean, this entire dance can take minutes, or it can take hours. Dedication, Kwong - dedication to the craft.
KWONG: So planet Earth is just a big ballroom for scorpions to make out in.
SOFIA: (Laughter) Yes. Yeah.
KWONG: Very, very, very cool. What's next?
SOFIA: OK, well an episode about courtship and wooing would not be complete without at least one bird.
VIVIANA RUIZ GUTIERREZ: They have some of the craziest and wildest and also visual and just auditory displays out of, you know, most of the creatures that we encounter.
SOFIA: That's Viviana Ruiz Gutierrez. She's an ecologist at the Cornell Lab of Ornithology. And she told me about a very special little bird called the loggerhead shrike.
GUTIERREZ: So loggerhead - their name actually comes from - because they have a really big head (laughter). So loggerhead strikes have a big appetite and a big head. And they need a big head because they actually have a hook at the end of their bill. And they use that to strike their prey. And they actually try to cut right to the spinal cord.
GUTIERREZ: So they're vicious little birds.
KWONG: This bird sounds positively metal.
SOFIA: (Laughter) You have no idea. You have no idea, Kwong. We're just warming up. It's only about the size of a robin, but it has been called - and this is real - a songbird with a raptor's habits.
KWONG: Put that in your Twitter bio.
SOFIA: Yeah, yeah, yeah. They hang out, like, high up on, like, telephone poles or whatever. And they dive bomb down, and they can kill prey that's pretty large for their size. But they're too little to eat something that big all at once. So...
SOFIA: ...Kwong, if you brought home more food than you can eat, what would you do?
KWONG: It's leftovers.
SOFIA: Yeah, yeah.
KWONG: But what does that have to do with courtship?
SOFIA: Just stay with me. Stay with me. It's just like you and your leftovers, except the way that they save their food - like, say, a bird that they've killed - is by impaling it on thorns or sharp sticks or even barbed wire.
KWONG: Evolution is so weird. (Laughter) I just need to say that right now.
GUTIERREZ: The first one that I saw, I saw a bird that was just, you know, impaled on a barbed wire fence when I was walking around. And you think, who did this?
GUTIERREZ: You don't think it was a bird. You really wonder, who would do such a thing?
SOFIA: A shrike, Emily. A shrike would do such a thing.
GUTIERREZ: Just like squirrels hide nuts away or, you know, other animals hide fruit, they actually save their prey for later. And, sometimes, they wedge them in between, like, forks and branches and they wedge anything from lizards to big insects to mice.
KWONG: Is this, like, a creepy dead creature sculpture that they're making?
SOFIA: (Laughter) I mean, yeah, kind of. OK, but here's where the courtship comes in because during breeding season, they go out and catch something, like, something good, like a mouse. And then he'll start to call out. And this is a loose interpretation, of course. But it's like, hey, girl, I got a good mouse over here. I got it hung up, skewered it just for you. And he'll kind of present this prey to her while he's doing these dance moves.
KWONG: Oh, my God (laughter).
GUTIERREZ: They have a bowing behavior that they do. And really, from the courtship and the kind of bowing behavior in the dance to then offering them the prey item, it really is kind of presenting themselves as, you know, a very suitable mate.
SOFIA: I mean, these birds bring the drama, Kwong. I mean, this is my favorite. Viviana told me that when they're little fledglings, they will imitate their parents' hunting behaviors.
SOFIA: So they'll, like, pick up random stuff and try to smash it into a branch like they're trying to impale it. It's adorable.
KWONG: These are the theater kids of the bird world...
KWONG: ...I'm just going to say it - like, the emo theater kids of the bird world.
SOFIA: They got props. They got choreography. They're writing the music.
SOFIA: I knew you would love this. I knew you would love this. And, I mean, I love it because it's just very straightforward. It's not, like, a flashy mating dance. The male has to provide food during this entire reproductive process. So he's just like, look. I can feed you. Love me.
GUTIERREZ: It's as if, you know, before you went on a date, somebody came with a, you know, week's worth of groceries and said (laughter), this is what I could provide for you (laughter).
KWONG: You know, that would work for me.
SOFIA: (Laughter) Right, right.
KWONG: OK, so just to summarize, to celebrate Valentine's Day, I brought you facts about chocolate.
KWONG: And you brought me a scorpion dancing and a bird that fills his little pantry with old dead bodies to find a mate.
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SOFIA: Do you not like it? Do you not like my gift?
KWONG: I love it. I love it, Maddie.
KWONG: Happy Valentine's Day to you and to all of our listeners out there. By the way, if you want to hear more from that chocolate expert, Life Kit has a whole episode about how to taste and appreciate chocolate with journalist Simran Sethi. You can find that at npr.org/lifekit.
SOFIA: This episode was produced by Brit Hanson and Rebecca Ramirez, fact-checked by Rasha Aridi and edited by Viet Le. I'm Maddie Sofia.
KWONG: And I'm Emily Kwong. Thanks for listening to SHORT WAVE, the daily lovecast from NPR.
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