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Transcript SACHA PFEIFFER, HOST: It's time now for our science news roundup from Short Wave, NPR's science podcast. With me are host Regina Barber and science correspondent Ari Daniel. Hi to both of you.
REGINA BARBER, BYLINE: Hi. ARI DANIEL, BYLINE: Hello there. PFEIFFER: So as usual, you have brought us three science stories that caught your attention recently.
What three do you have this week? BARBER: How eating with somebody could help manage your blood sugar. DANIEL: Plus, really loud birds.
BARBER: (Laughter) And the origin story of Bennu, the asteroid NASA visited to bring back samples. PFEIFFER: Let's start with the blood sugar one. That's very interesting.
I'm wondering if you're going to talk to us about the calming effect of a group meal. So tell us what's going on that says that eating with someone could help manage your blood sugar? BARBER: Yeah, so researchers in Israel gave participants the same amount of carbs to eat.
So in this case, it was bread. Then they measured their blood glucose levels, and they found, compared to people who ate alone, people who ate together were better at regulating their blood sugar. PFEIFFER: Regulating like it didn't spike as high?
DANIEL: Yeah, and their blood sugar came back down to baseline quicker. Basically, they recovered faster from the sugar high. Researchers calculated the social group was 24% more efficient at clearing glucose from their blood.
The results are published in the journal Science Advances. PFEIFFER: And why? Why would eating not by yourself but with other people or another person make a difference?
BARBER: Yeah, so lead author Shir Atzil thinks one possibility is that our brains associate other people with eating, and that social cue might push our brains to start the metabolizing process earlier, like by releasing insulin sooner, which helps regulate blood sugar. DANIEL: And behavioral neuroscientist James Coan offered another idea to support these results - that our brains could interpret company as help is here if we need it, and so your body may not require as much sugar at the ready, and you could use it elsewhere, like to grow hair or store it. JAMES COAN: You can do other things with it than dump it into your bloodstream.
PFEIFFER: You know, this is very relevant to me today because I went to NPR's in-house cafeteria at a little cafe. I got food, brought it to my desk and ate it all by myself. And it sounds like you're saying maybe I shouldn't do that all the time.
BARBER: Maybe, yeah. Both James and Shir say this is a reason to prioritize our friendships and social lives. And Shir also thinks this is evidence that our social nature as humans is rooted in our biology.
SHIR ATZIL: Maybe social bonds are actually rooted in the most basic physiological processes or what I call homeostasis. BARBER: So what I'm saying, Sacha, is I'm happy to eat lunch with you when I see you. You don't have to go...
PFEIFFER: Next time, we'll go to the cafeteria together, Regina. BARBER: Yeah. PFEIFFER: (Laughter) All right, tell me about your next topic, which is loud birds.
DANIEL: Right. So scientists have been studying bird vocalizations for well over a century, Sacha. And there's a ton of variation between species, says Jeff Podos, a behavioral ecologist at UMass Amherst.
JEFF PODOS: Because they're all communicating about the same sort of stuff - about being territorial or trying to attract mates - that raises questions as to why we have all that diversity. DANIEL: Most studies have focused on pitch and rhythm, but hardly ever on volume. PFEIFFER: I would have thought that maybe volume would be the first thing they study.
It seems like it's so straightforward. It's the thing we most focus on. BARBER: Yeah, you would think, but it hasn't been easy to do it in the wild until recently with devices like sound level meters and laser range finders.
PFEIFFER: All right, so if scientists can figure out the volume of bird song, what can they learn from that? DANIEL: Well, what they want to do is they want to try to figure out how some birds sing louder than others, and perhaps why. So several years back, Podos and his Ph.D. student at the time, Joao Menezes, set out to do just that.
They recorded birds in western Massachusetts in fields and swamps and suburbia and all across Brazil, Joao's home country, from the top of a more than mile-high mountain to his balcony in Sao Paulo. JOAO MENEZES: Even in your backyard, you feel like an early naturalist measuring something for the first time. BARBER: In a paper they published in the journal Evolution, they collected the volumes of 123 different species.
PFEIFFER: So they got a really large range. DANIEL: It was staggering. BARBER: Yeah.
DANIEL: There was an 800-fold difference between the softest species, a kind of hummingbird you can barely hear... (SOUNDBITE OF HUMMINGBIRD SINGING) DANIEL: All the way up to a very loud trio. MENEZES: Comparable to the level of a jackhammer. DANIEL: Including two species that are new contenders for world's loudest bird, the bare-throated bellbird... (SOUNDBITE OF BARE-THROATED BELLBIRD SINGING) PFEIFFER: (Laughter).
DANIEL: And the red-legged seriema. (SOUNDBITE OF RED-LEGGED SERIEMA SINGING) PFEIFFER: They really did their homework, didn't they? BARBER: Yeah, and they found that larger species and those with wider mouth openings tend to sing louder. PFEIFFER: All right.
I get if you have a wider mouth opening, that anatomically maybe you can belt it out more. Any idea why there is so much variety among all this? BARBER: They don't have the answer just yet.
The scientists couldn't find any clear patterns. But here is a cool fact - some of these birds are actually louder than the published values of certain mammals, like lions and wolves and elephants. PFEIFFER: You know, that initially seems hard to believe, but then I think about the times I've been woken up by crows in the mornings.
DANIEL: Yeah. BARBER: Yeah. PFEIFFER: So yes, maybe birds can, you know, outloud an elephant at certain times.
BARBER: Yeah. DANIEL: Better than being woken up by a lion. PFEIFFER: (Laughter) Much better.
BARBER: True. DANIEL: We chatted with Sue Anne Zollinger, an ornithologist at Manchester Metropolitan University in the U.K. who wasn't involved in the research. She was impressed with the study, but acknowledged it's natural for such a broad survey to have its constraints.
SUE ANNE ZOLLINGER: You can't really go into a lot of detail about the mechanics that might underlie these differences. PFEIFFER: Oh, scientists study such interesting things, don't they? BARBER: Yeah.
PFEIFFER: Right, for our last topic, it was something to do with asteroid samples. Tell us about that one. BARBER: Yeah, it's something that truly boggles my mind.
NASA sent a spacecraft to Bennu - this is a asteroid that comes pretty close to Earth every six years - to collect samples, and they brought those samples back to Earth. DANIEL: The samples landed in the Utah desert in September of 2023, and these precious rocks and dust grains were sent to scientists around the world to study. We talked to one of those researchers, Larry Nittler at Arizona State University.
LARRY NITTLER: Literally, I get in the mail a box, and inside it is a little glass container with a little tiny, tiny black rock. And I'm like, this came from outer space. PFEIFFER: (Laughter) And so what do those little black rocks tell them?
BARBER: Yeah, a lot. Another chemist named Maria Schonbachler also got a little stash of these rocks. She and her team looked at the chemical signatures and compositions of these samples, and they determined that Bennu actually formed a lot closer to the sun than previously thought.
And this has huge implications. MARIA SCHONBACHLER: It goes back to very, very basic questions. Where are we coming from?
How did life emerge on Earth? And if we want to answer this question, we can actually, but we need more of this material. That's why we need these samples here on Earth in the labs.
BARBER: They wrote about all of this in the journal Science Advances. PFEIFFER: We just heard her say that these samples could help answer the question of how life emerged on Earth. How could it tell us that?
DANIEL: Well, the origins of this asteroid could give us some hints. The study suggests Bennu formed in the part of the solar system called the water ice line, basically right before you hit Jupiter. If that's true, that could mean that when the solar system was just forming, asteroids like Bennu could have brought water and possibly organic material to the young Earth.
BARBER: And Sacha, I want to say that getting these samples from Bennu and another asteroid, Ryugu, is crucial because the only space rocks that scientists have studied before were meteorites that survived the fiery journey through our atmosphere and then crashed into Earth. But just studying stuff that falls to Earth means we might be missing a huge part of the picture of what's really going on out there. PFEIFFER: That was Regina Barber and Ari Daniel of NPR's science podcast Short Wave.
That's where you can learn about new discoveries and everyday mysteries. Regina and Ari, thanks to both of you. DANIEL: Thank you, Sacha.
BARBER: Thank you. (SOUNDBITE OF OLIVER TREE SONG, "ALIEN BOY") Copyright © 2026 NPR. All rights reserved. Visit our website terms of use and permissions pages at www.npr.org for further information.
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