Short Wave — "How did these flowers evolve to survive a megadrought?"

Podcast: Short Wave (NPR)
Episode Date: March 20, 2026
Hosts: Emily Kwong, Nate Rott, Elsa Chang (guest host)
Length: ~10 minutes of content

Episode Overview

This episode of Short Wave features a lively science news roundup discussing three recent and intriguing discoveries: how wildflowers evolved to survive a megadrought, the mechanics of birds' dust bathing, and the surprising social lives of bull sharks. Hosts Emily Kwong and Nate Rott are joined by Elsa Chang from All Things Considered for a fast-paced, informative, and occasionally humorous look at the stories behind the headlines.

1. Scarlet Monkey Flower: Evolution Amid Drought

Segment Start: [02:34]

• Introduction:
  Elsa chooses to start with the story of the scarlet monkey flower, a wildflower native to California and Oregon, notable for its vibrant red, monkey-face-like petals.
• Biologist Daniel Anstedt (Cornell University):
  Describes the plant as “bright red … with all this kind of pollen up front that's really set up for a hummingbird to just kind of fly in and drink some nectar.” ([02:47])
• The Mystery:
  While scarlet monkey flowers typically die quickly without water, some wild populations survived an intense megadrought. This phenomenon was the subject of a new paper in Science.
• Secret to Survival: Rapid Evolution
  • Some populations underwent "rapid evolution," meaning genetic changes took place over just a few years, enabling survival during extreme drought.
  • The key trait: stomata (plant “pores”) that open less frequently, conserving water—an adaptation that allowed these plants to endure. ([03:34])
  • Quote: Emily explains, “That’s basically like a plant’s pores. And this allowed the scarlet monkey flowers to hunker down in the drought. Slow and steady survives.” ([03:45])
• Long-Term Impact:
  • The team, led by Daniel Anstedt, tracked the same flower populations for over a decade; they are collecting seeds for genetic sequencing, aiming to build a generational study akin to Darwin’s finches. ([04:08])
  • Daniel Anstedt: "That's what we hope to build with this study. Is this long term study because, yes, rapid evolution happened great. ... But what are the longer decadal consequences?" ([04:16])
• Open Questions:
  • Will these rapidly adapted flowers maintain enough genetic diversity to respond to future environmental changes, like insect infestations or future deluges?

2. Dust Bathing Birds: Nature’s ‘Sandblasting’

Segment Start: [04:42]

• Introduction:
  Elsa is fascinated by the idea of “dust bathing” in birds—a behavior she likens to a spa treatment.
• What is Dust Bathing?
  • Described as chickens (and other birds like ostriches, turkeys, and some songbirds) digging into dirt or sand, wriggling their wings and tossing sand over themselves.
  • Emily jokingly claims, “I did it this morning. I highly recommend.” ([05:04])
• Why Birds Dust Bathe:
  • Maintains healthy feather oil balance—like “dry shampoo” for birds ([05:33])
  • Removes parasites, including feather mites which “can burrow into a bird plumage and cause itching, scabbing, anemia, and all sorts of other bad things.” ([05:47])
• The Study:
  • Conducted by Patricia Yang (National Tsinghua University, Taiwan) and published in PNAS.
  • Experiment: Collected mite-covered chicken feathers, vibrated them in sand at 4–5 times per second (mirroring birds’ wing shakes). Result: Nearly all mites were removed. ([06:17])
• Takeaway:
  • Nate summarizes, “Basically what the birds are doing is sandblasting themselves.” ([06:40])
  • Guest engineer Andrew Dickerson (University of Tennessee) notes this supports the idea that animals evolved optimized ways to remove contaminants, and engineers might one day mimic these techniques.
• Fun Aside:
  Elsa jokes about trying sand baths for humans with lice: “I have some sand the next time I get infested, guys.” ([06:35])

3. Bull Sharks Have Friends: Social Lives Underwater

Segment Start: [07:14]

• Introduction:
  Nate, an avid surfer, brings up a study about the social behaviors of bull sharks.
• Bull Sharks:
  • Large, globally distributed sharks typically found in warm, shallow waters.
  • Emily: “They’re really social, and they like hanging out with each other.” ([07:27])
• Study Details:
  • Shark scientist Natasha Morosi and her team studied 184 bull sharks over six years at Fiji’s Shark Reef Marine Reserve.
  • Identification via tags, video, and even individual scars or swimming patterns: “Natasha can actually tell who’s who just by like looking at their wounds or scars and sometimes just by the way they swim.” ([08:08])
• Findings:
  • Sharks were observed forming consistent social groups—such as the “boys club” trio: Chunky, Mogul, and Shark Bite.
  • Encounters were not random; sharks demonstrated preference, swimming parallel or altering direction to be with specific others ([08:41]).
  • Middle-aged sharks appeared at the center of these networks, while young and old were less connected.
• Caveats:
  • Guest researcher Catherine McDonald urges caution: while behaviors are social, they shouldn’t be equated too closely with human friendship.
• Humorous Moment:
  • Nate highlights the paper’s title: “Rolling in the Deep. Dun dun dun dun dun.” ([09:21])

Notable Quotes & Memorable Moments

• Emily Kwong (re: monkey flowers):
  “That’s basically like a plant’s pores. And this allowed the scarlet monkey flowers to hunker down in the drought. Slow and steady survives slow and steady.” ([03:45])
• Daniel Anstedt (Cornell biologist):
  “...But what are the longer decadal consequences?” ([04:16])
• Elsa Chang (on dust bathing):
  “Sand does not sound comfortable to me at all.” ([05:29])
  “I have some sand the next time I get infested, guys.” ([06:35])
• Nate Rott (on dust bathing):
  “Basically what the birds are doing is sandblasting themselves.” ([06:40])
• Emily Kwong (on sharks):
  “They’re really social, and they like hanging out with each other.” ([07:27])
• Elsa Chang (on shark pals):
  “Chunky, Mogul and Shark Bite, the Voice Club. I love it.” ([08:26])
• Nate Rott (on paper title):
  “Rolling in the Deep. Dun dun dun dun dun.” ([09:21])

Key Timestamps

• [02:34] — Begin wildflower evolution segment
• [03:34] — Explanation of stomata adaptation
• [04:16] — Ambitions for long-term evolutionary studies
• [04:42] — Begin segment on dust-bathing birds
• [06:17] — Sand-vibration experiment details
• [06:40] — "Sandblasting" analogy
• [07:14] — Begin bull shark segment
• [08:41] — Methods for identifying shark friendships
• [09:21] — Shark study paper's humorous title

Summary & Takeaways

This episode brings together three fascinating snippets from the natural world:

• Rapid evolution allows certain plants to survive unforgiving droughts, shedding light on both the variability and adaptability of life.
• Birds’ unusual “dust baths” aren’t just quirky behavior—they’re a refined evolutionary response to parasites, with potential inspiration for engineers.
• Sharks, often stereotyped as lone predators, can form lasting group bonds and intricate social networks.

In just ten minutes, the episode serves up vibrant conversation, humor, and illuminating science, making it engaging listening for science fans and the curious alike.