The Knowledge
How dolphins communicate – new discoveries from a long‑term study in Sarasota, Florida
Laela Sayigh, Woods Hole Oceanographic Institution
Human fascination with bottlenose dolphins goes back thousands of years, at least as early as Greek mythology.
But it wasn’t until the 1960s that methodical research into dolphin communication began. Scientists like John Lilly and the husband-and-wife team of Melba and David Caldwell tried various experiments to decipher the sounds dolphins can make.
The Caldwells figured out a way to record isolated animals in human care. They discovered that each individual dolphin communicated mostly with one unique whistle, which they called the “signature whistle.” Researchers now know that these whistles convey identities much like human names do. Dolphins use them to stay in touch with each other in their murky habitat, where vision is limited. It’s like announcing “I’m over here!” when someone can’t see you.
This discovery is foundational to my own research. I’ve been studying communication in wild dolphins since the mid-1980s, when I joined my mentor Peter Tyack in documenting signature whistles in wild dolphins for the first time. Our team’s research focused on a resident community of free-ranging bottlenose dolphins in waters near Sarasota, Florida, where I continue to work today.
This collaborative study, led by Randall Wells of Brookfield Zoo Chicago’s Sarasota Dolphin Research Program, involves numerous researchers from a variety of institutions, who study different aspects of dolphin biology, health, ecology and behavior. Begun in 1970, this is the longest-running research project on a population of wild cetaceans – whales, dolphins and porpoises – in the world.
Recording and observing
Researchers know the age, sex and maternal relatedness of almost all of the approximately 170 dolphins in the Sarasota community. This depth of knowledge provides an unprecedented opportunity to study communication in a wild cetacean species.
The dolphins in the Sarasota project are periodically subject to brief catch-and-release health assessments, during which researchers, including me, briefly handle individual dolphins.
Our team attaches suction-cup hydrophones directly onto each dolphin’s melon – that is, its forehead. We then record the dolphins continuously throughout the health assessments, taking notes on who is being recorded when, and what is happening at the time.
This is how my colleagues and I were able to confirm that wild dolphins, like captive animals, produced large numbers of individually distinctive signature whistles when briefly isolated from other dolphins. Through observations and recordings of known free-swimming dolphins, we were further able to confirm that they produced these same signature whistles in undisturbed contexts.
We have organized these recordings into the Sarasota Dolphin Whistle Database, which now contains nearly 1,000 recording sessions of 324 individual dolphins. More than half of the dolphins in the database have been recorded more than once.
We identify each dolphin’s signature whistle based on its prevalence: In the catch-and-release context, about 85% of the whistles that dolphins produced are signature whistles. We can identify these visually, by viewing plots of frequency vs. time called spectrograms.
Signature whistles and ‘motherese’
The Sarasota Dolphin Whistle Database has proved to be a rich resource for understanding dolphin communication. For instance, we have discovered that some calves develop signature whistles similar to those of their mothers, but many do not, raising questions about what factors influence signature whistle development.
We have also found that once developed, signature whistles are highly stable over an animal’s lifetime, especially for females. Males often form strong pair bonds with another adult male, and in some instances, their whistles become more similar to one another over time. We are still trying to understand when and why this occurs.
Dolphin mothers modify their signature whistles when communicating with their calves by increasing the maximum frequency, or pitch. This is similar to human caregivers using a higher-pitched voice when communicating with young children – a phenomenon known as “motherese.”
Slowed recording of a bottle-nosed dolphin without her calf, then with her calf. Courtesy of Laela Sayigh of Woods Hole Oceanographic Institution, and Brookfield Zoo Chicago’s Sarasota Dolphin Research Program. These sounds were obtained under a federal scientific research permit issued to R. Wells of SDRP.72 KB (download)
Also similar to humans is how dolphins will initiate contact with another dolphin by imitating their signature whistle – what we call a signature whistle copy. This is similar to how you would use someone’s name to call out to them.
Our team is interested in finding out if dolphins also copy whistles of others who aren’t present, potentially talking about them. We have seen evidence of this in our recordings of dolphins during health assessments, which provide a rare context to document this phenomenon convincingly. But we still have more work to do to confirm that these are more than chance similarities in whistles.
Shared whistle types
Another exciting development has been our recent discovery of shared whistle types — ones that are used by multiple animals and that are not signature whistles. We call these non-signature whistles.
I could hardly believe my ears when I first discovered a repeated, shared non-signature whistle type being produced by multiple dolphins in response to sounds we play back to them through an underwater speaker. We had previously believed that these non-signature whistles were somewhat random, but now I was hearing many different dolphins making a similar whistle type.
Our team originally had been using the playbacks to try to determine whether dolphins use “voice cues” to recognize each other – similar to how you can recognize the voice of someone you know. Although we found that dolphins did not use voice cues, our discovery of shared non-signature whistle types has led to an entirely new research direction.
So far, I’ve identified at least 20 different shared non-signature whistle types, and I am continuing to build our catalog. We are hoping that artificial intelligence methods may help us categorize these whistle types in the future.
To understand how these shared non-signature whistle types function, we are carrying out more playback experiments, filming the dolphins’ responses with drones. We’ve found that one such whistle often leads the dolphins to swim away, suggesting a possible alarm-type function. We have also found that another type might be an expression of surprise, as we have seen animals produce it when they hear unexpected stimuli.
More difficult, more interesting
So far, the main takeaway from our experiments has been that dolphin communication is complex and that there are not going to be one-size-fits-all responses to any non-signature whistle type. This isn’t surprising, given that, like us, these animals have complicated social relationships that could affect how they respond to different sound types.
For instance, when you hear someone call your name, you may respond differently if you are with a group of people or alone, or if you recently had an argument with someone, or if you’re hungry and on your way to eat.
Our team has a lot more work ahead to sample as many dolphins in as many contexts as possible, such as different ages, sexes, group compositions and activities.
This makes my job more difficult – and far more interesting. I feel lucky every day I am able to spend working on the seemingly infinite number of fascinating research questions about dolphin communication that await answers.
This article has been corrected to better describe how dolphins respond to playback whistles.
Read more stories from The Conversation about Florida.
Laela Sayigh, Senior Research Specialist, Cetacean Communication, Woods Hole Oceanographic Institution
This article is republished from The Conversation under a Creative Commons license. Read the original article.
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The Knowledge
Forgotten Genius Fridays: Madison Washington and the Slave Revolt That Changed History
Discover the inspiring story of Madison Washington, the courageous freedom fighter who led the 1841 Creole revolt, securing freedom for 128 enslaved people in the most successful slave uprising in American history.
When people think of heroic figures who fought against slavery, names like Harriet Tubman, Frederick Douglass, and Sojourner Truth often come to mind. Yet one remarkable man remains largely absent from history books despite leading the most successful slave revolt in American history.
His name was Madison Washington.
His courage aboard the brig Creole in 1841 transformed the lives of more than one hundred enslaved people and became a powerful symbol of the fight for freedom.
Born Into Slavery
Madison Washington was born into slavery in Virginia during the early 19th century. Like millions of enslaved African Americans, he endured the brutality and injustice of a system that denied him even the most basic human rights.
Determined to be free, Washington escaped slavery in 1839 and reached Canada with help from the Underground Railroad.
Freedom, however, came with heartbreak.
His wife remained enslaved in Virginia, and Washington made the extraordinary decision to risk everything by returning to rescue her.
Instead, he was captured and imprisoned.
The Voyage Aboard the Creole
In November 1841, Washington and 134 other enslaved people were forced aboard the American slave ship Creole. The vessel was headed from Virginia to New Orleans, where many of the captives would likely be sold to plantations across the Deep South.
Washington refused to accept that fate.
On November 7, he and several fellow captives launched a carefully planned revolt. During the struggle, one slave trader was killed, while much of the crew was subdued.
Rather than continue to New Orleans, Washington ordered the crew to sail to Nassau in the Bahamas.
Freedom in the Bahamas
The decision proved historic.
Great Britain had abolished slavery throughout most of its empire years earlier, and when the Creole arrived in Nassau, British authorities refused American demands to return the enslaved passengers as property.
Instead, 128 formerly enslaved people were granted their freedom.
The Creole revolt became the most successful slave uprising in United States history.
International Consequences
The incident sparked a diplomatic dispute between the United States and Great Britain that lasted for years.
Southern slaveholders demanded compensation for what they viewed as lost property, while abolitionists celebrated Madison Washington as a courageous freedom fighter who challenged one of history’s greatest injustices.
The event also strengthened arguments against slavery by demonstrating that people held in bondage would continue to resist oppression whenever opportunities arose.
Frederick Douglass Honors a Hero
Madison Washington’s bravery inspired one of America’s greatest abolitionists.
Frederick Douglass based his 1853 novella, The Heroic Slave, on Washington’s remarkable story. The work became one of the earliest pieces of African American fiction centered on a real historical figure and introduced many readers to Washington’s extraordinary leadership.
Although historical records about Washington’s later life remain scarce, his legacy lived on through Douglass’s writing and through the generations of freedom seekers who followed.
Why Madison Washington Matters Today
Madison Washington reminds us that history is filled with individuals whose contributions have been overlooked despite changing the course of events.
His story is about more than a shipboard revolt.
It is about courage in the face of impossible odds.
It is about sacrificing personal safety for loved ones.
And it is about the universal desire for freedom.
As we continue to uncover stories that have too often been left untold, Madison Washington deserves recognition alongside the great heroes of American history.
His determination helped secure freedom for more than one hundred people—and his legacy continues to inspire those who believe that justice is always worth fighting for.
Forgotten Genius Fridays
Every Friday, STM Daily News shines a light on remarkable people whose contributions have shaped our world but whose stories deserve greater recognition. Join us as we rediscover the innovators, pioneers, leaders, and trailblazers history should never forget.
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Related External Links
For readers interested in learning more about Madison Washington, the Creole revolt, and the broader history of slavery and abolition, these trusted resources provide additional historical context:
- Library of Congress – Frederick Douglass Papers: https://www.loc.gov/collections/frederick-douglass-papers/
- National Park Service – Underground Railroad: https://www.nps.gov/subjects/undergroundrailroad/index.htm
- Smithsonian National Museum of African American History and Culture: https://nmaahc.si.edu/
- National Archives – African American History: https://www.archives.gov/research/african-americans
- Encyclopaedia Britannica – Creole Revolt: https://www.britannica.com/event/Creole-slave-revolt
- Encyclopaedia Britannica – Frederick Douglass: https://www.britannica.com/biography/Frederick-Douglass
- Library of Congress – Slavery and the Struggle for Freedom: https://www.loc.gov/classroom-materials/slavery-and-the-struggle-for-freedom/
Note: External links are provided for educational and informational purposes. STM Daily News is not responsible for the content or policies of third-party websites.
🧠 Discover the remarkable innovators, inventors, and trailblazers who helped shape our world but rarely receive the recognition they deserve. Share your thoughts in the comments and subscribe to the STM Daily News newsletter to catch every new Forgotten Genius Friday feature and more inspiring stories delivered to your inbox.
Forgotten Genius Fridays
Katherine Johnson: The Human Computer Who Helped America Reach the Moon
Discover how Katherine Johnson’s mathematical genius helped NASA send astronauts into space and to the Moon. Learn why she remains one of America’s most inspiring scientific pioneers.
Forgotten Genius Friday | The Knowledge | STM Daily News
When the United States raced to explore space during the 1950s and 1960s, rockets and astronauts often captured the headlines. Behind every successful mission, however, was a team of brilliant mathematicians and engineers whose calculations made spaceflight possible. Among them was Katherine Johnson, an extraordinary mathematician whose work helped America reach orbit, the Moon, and beyond.
Although her contributions remained largely unknown for decades, Katherine Johnson’s remarkable career transformed the U.S. space program and inspired generations of scientists, engineers, and mathematicians.
A Gift for Mathematics
Katherine Coleman Goble Johnson was born on August 26, 1918, in White Sulphur Springs, West Virginia. From an early age, her exceptional talent for mathematics was evident. She skipped several grades, graduated from high school at just 14 years old, and earned degrees in mathematics and French from West Virginia State College by the age of 18.
At a time when educational and career opportunities for African American women were limited, Johnson’s determination and love of mathematics helped her overcome barriers that stood in the way of many aspiring scientists.
Joining America’s Space Program
In 1953, Johnson joined the National Advisory Committee for Aeronautics (NACA), the agency that would later become NASA.
She worked in the segregated West Area Computing Unit, where African American women served as “human computers,” performing complex mathematical calculations by hand. Their work was essential to aircraft research and, later, the nation’s ambitious efforts in human spaceflight.
Johnson’s exceptional analytical skills quickly earned the respect of engineers and mission planners. Rather than simply solving equations, she asked questions, challenged assumptions, and helped develop solutions to problems that had never been encountered before.
The Woman John Glenn Trusted
One of Katherine Johnson’s most famous moments came in 1962 before astronaut John Glenn became the first American to orbit Earth.
NASA had begun using electronic computers to calculate flight trajectories, but Glenn wanted one final verification before launch. According to NASA’s historical accounts, he requested that Katherine Johnson personally check the computer’s calculations.
“If she says they’re good,” Glenn reportedly said, “then I’m ready to go.”
Johnson confirmed the numbers, and Glenn successfully completed three orbits around Earth, marking a major milestone in the Space Race.
Helping America Reach the Moon
Katherine Johnson’s contributions did not end with Project Mercury.
She calculated trajectories for the Apollo program, helping engineers plan missions that ultimately carried astronauts to the Moon and safely back to Earth. Her work also supported the Space Shuttle program and early concepts for future space exploration.
Her calculations contributed to some of the most significant achievements in aerospace history, demonstrating the critical role mathematics plays in exploration and discovery.
Recognition Long Overdue
For much of her career, Katherine Johnson worked behind the scenes, receiving little public recognition. That changed in later years as historians and researchers began highlighting the contributions of the women who helped build America’s space program.
In 2015, President Barack Obama awarded Katherine Johnson the Presidential Medal of Freedom, the nation’s highest civilian honor.
A year later, her story reached millions through the acclaimed film Hidden Figures, which introduced audiences around the world to Johnson and her colleagues Dorothy Vaughan and Mary Jackson.
The movie helped shine a long-overdue spotlight on the women whose brilliance helped change history.
A Legacy That Continues to Inspire
Katherine Johnson passed away on February 24, 2020, at the age of 101, leaving behind a legacy of excellence, perseverance, and intellectual curiosity.
Her work reminds us that history is often shaped not only by those who step into the spotlight but also by those working quietly behind the scenes to solve impossible problems.
Today, students pursuing careers in science, technology, engineering, and mathematics continue to draw inspiration from her life and achievements. Her story demonstrates that talent, determination, and curiosity can overcome even the greatest obstacles.
As NASA prepares for a new era of lunar exploration and future missions to Mars, Katherine Johnson’s legacy remains woven into the history of every successful journey beyond our planet.
Why We Remember
Forgotten Genius Friday celebrates innovators whose achievements deserve greater recognition. Katherine Johnson’s extraordinary mathematical talent helped make space exploration possible, proving that one brilliant mind can help change the course of history.
Her calculations guided astronauts through some of humanity’s greatest adventures—and her legacy continues to inspire the explorers of tomorrow.
Related Links
- NASA: Katherine Johnson Biography
- NASA History
- National Park Service: Katherine Johnson
- West Virginia State University
🧠 Discover the remarkable innovators, inventors, and trailblazers who helped shape our world but rarely receive the recognition they deserve. Share your thoughts in the comments and subscribe to the STM Daily News newsletter to catch every new Forgotten Genius Friday feature and more inspiring stories delivered to your inbox.
News
Joby Aviation and Toyota kick off manufacturing alliance to scale electric air taxi production
Joby Aviation and Toyota launch a joint venture to improve productivity, quality, and cost as they prepare to scale electric air taxi production.
Joby Aviation and Toyota Motor Corporation have launched the initial phase of a strategic manufacturing alliance aimed at accelerating commercial production of electric air taxis—an early step the companies say is designed to make “air mobility for all” a practical, everyday reality.
Announced June 30, 2026, the partnership formalizes a new joint venture that will combine Joby’s electric aviation development with Toyota’s production systems and operational expertise. The near-term focus: building the groundwork for commercial production while pushing improvements in productivity, quality, and cost—key factors as the industry moves from prototypes to scaled manufacturing.
What the joint venture is designed to do
According to the companies, the alliance will initially concentrate on:
- Establishing the foundation for commercial production capability
- Advancing manufacturing excellence with an emphasis on productivity, quality, and cost
- Supporting expansion of Joby’s production capacity as it works toward aircraft certification and prepares for anticipated demand
The announcement positions Toyota’s manufacturing playbook—known globally for lean production and continuous improvement—as a lever to help Joby move from development into repeatable, high-quality output at scale.
Why it matters: eVTOLs need scale, not just flight tests
Electric vertical take-off and landing (eVTOL) aircraft have become one of the most closely watched bets in next-generation transportation, but the path to viable air taxi services depends on more than successful test flights. Certification timelines, supply chain readiness, and the ability to produce aircraft consistently (and affordably) are often what separates promising technology from commercial reality.
By forming a joint venture focused on manufacturing readiness, Joby and Toyota are signaling that the next competitive frontier is industrialization—how quickly and reliably eVTOL aircraft can be built to meet safety standards and market demand.
Related Links for Further reading
- Joby Aviation (official): https://www.jobyaviation.com
- Joby Investor Relations / News (official updates & filings): https://ir.jobyaviation.com
- Toyota Newsroom (official): https://www.toyotanewsroom.com
- Toyota Global (corporate overview): https://global.toyota/en
- FAA Advanced Air Mobility / Air Taxis (context): https://www.faa.gov/air-taxis
What executives are saying
Joby founder and CEO JoeBen Bevirt emphasized the long-running relationship between the companies, calling the joint venture a reflection of shared confidence in the opportunity ahead.
“Toyota has been by Joby’s side for nearly a decade, providing invaluable guidance and support as we built the foundation for manufacturing our aircraft,” Bevirt said. “Together, we share a vision of making aerial mobility an everyday reality.”
Toyota Motor Corporation Chairman Akio Toyoda framed air mobility as an extension of the company’s broader mission.
“Since our founding, we’ve been guided by the philosophy of providing mobility for all,” Toyoda said, adding that Toyota views air mobility as “a natural extension of that philosophy—from the ground into the sky.”
About the companies
Joby Aviation (NYSE: JOBY) is a California-based transportation company developing an all-electric eVTOL air taxi. The company intends to operate its own air taxi service in cities worldwide and sell aircraft to other operators and partners.
Toyota (NYSE: TM) has operated in North America for nearly 70 years and says it is focused on sustainable, next-generation mobility through Toyota and Lexus brands. Toyota reports nearly 64,000 employees in North America, 14 manufacturing plants, and more than 1,800 dealerships. The company also noted that its North Carolina plant began assembling automotive batteries for electrified vehicles in 2025.
What to watch for next
For readers tracking the air taxi sector, the next milestones will likely center on:
- Details on how the joint venture will be structured operationally
- Updates on Joby’s certification progress and production ramp timelines
- Signs of how manufacturing improvements translate into cost reductions and throughput
- Additional agreements or expanded collaboration as the alliance progresses
While the companies highlighted expected benefits, they also noted the usual forward-looking risks—such as regulatory certification timelines, market conditions, and the ability to finalize additional agreements.
Source: Toyota Motor North America / PRNewswire (June 30, 2026)
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