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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Forgotten Genius Fridays
Octavia E. Butler: The Black Woman Who Helped Change Science Fiction
Discover how Octavia E. Butler transformed science fiction, explored Black identity, and helped shape Afrofuturism through her groundbreaking novels.
Last Updated on October 16, 2026 by Daily News Staff
Forgotten Genius Friday | The Knowledge | STM Daily News
Octavia E. Butler: The Woman Who Reimagined the Future
When we think about science fiction, we often picture spaceships, robots, alien civilizations, and futuristic technology. But what happens when science fiction becomes a way to explore racism, inequality, human survival, and the consequences of our choices?
That is exactly what Octavia E. Butler brought to the genre.
Long before Afrofuturism became a widely recognized cultural movement, Butler was creating extraordinary stories that placed Black characters—especially Black women—at the center of imagined futures.
Her work challenged conventional ideas about who could be a hero, whose experiences mattered, and what science fiction could accomplish.
A Young Girl With a Powerful Imagination
Octavia Estelle Butler was born on June 22, 1947, in Pasadena, California.
Raised primarily by her mother and grandmother after her father’s death, Butler grew up shy and found comfort in books and storytelling.
Her mother worked as a domestic employee, and Butler sometimes accompanied her to work. Those experiences exposed her to the racial and economic inequalities that would later influence her fiction.
As a child, Butler loved science fiction, but she noticed something missing: people who looked like her.
Rather than accepting that absence, she began creating stories of her own.
She would eventually become one of the most influential writers in speculative fiction.
Breaking Barriers in Science Fiction
During the 1970s, mainstream American science fiction was largely associated with white male writers and protagonists.
Butler entered that literary world with a different perspective.
Her first published novel, Patternmaster, appeared in 1976. It introduced readers to a world shaped by extraordinary mental abilities, social hierarchies, and struggles for power.
Butler continued developing complex stories that explored humanity’s relationship with authority, identity, biology, and survival.
In 1979, she published one of her best-known novels, Kindred.
The book follows Dana, a Black woman living in 1970s California who is repeatedly transported back to a Maryland plantation before the Civil War.
Through Dana’s experiences, Butler forced readers to confront the brutality of American slavery and its continuing influence on the present.
Rather than treating history as something safely confined to the past, Kindred makes that history immediate and deeply personal.
Imagining the Future—and Warning Us About It
In 1993, Butler published Parable of the Sower, a novel set in a collapsing American society struggling with economic inequality, environmental destruction, violence, and weakened institutions.
Its central character, Lauren Olamina, is a young Black woman who develops a philosophy called Earthseed while searching for a way to survive and build a community.
The novel takes place beginning in 2024, making its imagined future particularly striking to modern readers.
Butler followed it with Parable of the Talents in 1998, continuing her examination of social instability, religious extremism, authoritarianism, and the struggle to create a better future.
Her novels were not literal predictions. They were works of speculative fiction that used recognizable social trends to ask difficult questions about where humanity might be headed.
Octavia Butler and Afrofuturism
Afrofuturism brings together African and African diasporic experiences with science fiction, technology, history, mythology, and imaginative visions of the future.
While artists such as Sun Ra and George Clinton explored cosmic identity through music, performance, and futuristic imagery, Butler used literature to investigate power, history, and humanity’s possible futures.
Her novels frequently placed Black women in situations where they had to navigate extraordinary challenges and reshape the societies around them.
Butler’s work is widely discussed within Afrofuturist scholarship, although her literary contributions also extend beyond any single cultural label.
She demonstrated that Black people did not have to remain secondary characters in someone else’s vision of the future.
They could be the architects of entirely new worlds.
Recognition and a Lasting Legacy
Butler received some of science fiction’s most significant honors, including Hugo and Nebula Awards.
In 1995, she became the first science-fiction writer to receive a MacArthur Fellowship, often called a genius grant.
Her work also included the Xenogenesis trilogy, later collected as Lilith’s Brood, which explored humanity’s encounter with an extraterrestrial species and raised questions about consent, adaptation, identity, and survival.
Butler died on February 24, 2006, at age 58.
Yet her influence has continued to grow.
Her novels are studied in classrooms, discussed by scholars, and embraced by new generations of readers and creators interested in science fiction, social justice, and Afrofuturism.
A Genius Who Made Us Think Differently About Tomorrow
Octavia E. Butler was more than a science-fiction author.
She was a visionary storyteller who understood that imagining the future also meant examining the past and questioning the present.
Her stories asked readers to consider how power operates, how communities survive, and how human beings might change.
And perhaps her greatest contribution was demonstrating that the future belongs in the imagination of everyone.
Why Octavia E. Butler Belongs in Forgotten Genius Friday
At STM Daily News, our Forgotten Genius Friday series celebrates extraordinary individuals whose ideas, innovations, and accomplishments helped shape our world, even if their stories aren’t widely known. Octavia E. Butler fits that mission perfectly. Although she received prestigious literary awards and recognition during her lifetime, her influence extends far beyond science fiction. Like the inventors, scientists, and trailblazers we’ve featured in this series, Butler challenged barriers, defied expectations, and opened doors for future generations. Through her imagination, she helped redefine who could tell stories about humanity’s future—and who could be at the center of those stories. Her inclusion in Forgotten Genius Friday reminds us that genius isn’t limited to laboratories and inventions. Sometimes, it begins with a pen, a powerful imagination, and the courage to envision a different world.
Sources and fact-checking
The Huntington Library holds Butler’s literary archive and confirms the chronology of her major novels, awards, and career. The MacArthur Foundation independently documents her 1995 fellowship.
- Official Octavia E. Butler biography
- The Huntington — Octavia E. Butler Papers
- MacArthur Foundation — Octavia Butler
- The Huntington — Telling My Stories exhibition
For more stories about overlooked innovators, writers, scientists, and visionaries who changed our world, explore The Knowledge and Forgotten Genius Friday at STM Daily News.
Food Truths
Soul Food Has African Roots—and a Distinct Black American History
Soul food connects African heritage with generations of Black American creativity and community. Here’s why shared roots and a distinct cultural identity both deserve recognition.
Last Updated on October 15, 2026 by Daily News Staff
Shared ancestry connects the African diaspora. It also makes understanding each community’s food traditions worth the effort.
A debate over who can claim soul food raises a question larger than any social media argument: When does a shared cultural inheritance become a distinct tradition?
People across Africa and the African diaspora have foods that evoke home, family, comfort, and belonging. Recognizing that connection is valuable. But using “soul food” as a general description of comforting food is different from identifying the cuisine historically known by that name.
Soul food is a distinctly African American culinary tradition with African roots, shaped by generations of Black life in the United States. Recognizing its American development does not erase Africa. Recognizing Africa should not erase what Black Americans created.
African Roots, American Development
Enslaved Africans arrived with agricultural knowledge, cooking skills, and food traditions. They adapted those traditions to unfamiliar surroundings and unequal access to food, drawing on available ingredients and encounters with Indigenous and European foodways.
Okra, black-eyed peas, and vegetable-centered cooking offer important connections to African traditions. Corn and cornmeal reflect Indigenous American agriculture. These ingredients and influences became part of an evolving food culture rather than remaining unchanged copies of dishes from another continent. [1]
The distinction is between ancestry and development. A cuisine can descend from older traditions and acquire its own identity through the experiences of the people who preserve and transform it.
More Than a Story About Scraps
Slavery and deprivation belong in this history. Enslaved people supplemented restricted food supplies through gardening and other means, and used small amounts of meat to season vegetables. But telling the entire story as “making something out of scraps” understates their knowledge and creativity.
Black food history also includes seafood work, farming, skilled cooking, and enterprise. The Smithsonian’s account of Black foodways, for example, documents African Americans’ extensive involvement in harvesting, processing, and selling oysters. [2]
These were people with expertise. Their contributions deserve recognition as culinary work and cultural creation.
Why the Name Matters
The food traditions are older than the widespread use of the name “soul food.” The term became prominent during the 1960s, amid movements asserting Black identity and cultural pride. Smithsonian histories describe the soul food movement as celebrating foods that mainstream America had often disparaged. [3]
That context gives the name meaning beyond a meal that tastes good or brings comfort.
For some families, a pot of greens or a pan of cornbread carries memories of relatives, church dinners, holidays, and recipes learned by watching someone cook. Calling those foods “soul food” places them within a particular cultural story.
Southern Roots Traveled
Soul food also developed beyond the South. During the Great Migration, Black Americans carried Southern food traditions into new cities and neighborhoods, preserving familiar dishes while adapting their cooking. Smithsonian programming connects that movement directly to soul food’s development. [4]
That helps explain how a cuisine rooted in the South became part of Black community life across the country.
It also makes geography an imperfect test of authenticity. Soul food cooked in London can still be African American soul food. A cuisine’s cultural origins do not change simply because someone prepares it elsewhere.
Shared Heritage Does Not Mean Identical Cultures
Africa is a continent of many food traditions. The diaspora is similarly diverse. African American, Afro-Caribbean, Afro-Latin American, and Black British identities encompass different histories and relationships to food.
Someone may use “soul food” figuratively to describe a cherished family dish. That emotional use is understandable. The difficulty arises when it becomes a historical claim that all Black cuisines are versions of the same named tradition.
Shared ingredients and ancestry establish connections; they do not make distinct cuisines interchangeable.
A useful conversation would ask which dishes are related, what techniques survived, and how different communities adapted them. That approach gives people more history to appreciate.
Respect Through Recognition
Defending soul food’s African American identity need not become an attack on Africans, Caribbean people, or Black Britons. Equally, celebrating connections across the diaspora should include respect for Black Americans’ particular contributions.
Anyone can cook, enjoy, study, and share soul food. Cultural recognition does not require closing the kitchen door. It requires crediting the people and history behind the cuisine.
Soul food’s African roots and African American identity belong in the same sentence. Both deserve to be remembered.
What dish connects you most strongly to your family’s history—and who taught you to make it? Share your story in the comments.
Explore more food stories and culinary traditions in STM Daily News’ Food & Drink section.
Sources and Further Reading
- African and Native American Foodways and Resilience: From 1619 to COVID-19 — Research on food traditions, adaptation, and cultural resilience.
- Black Foodways and Cuisine — National Museum of African American History and Culture.
- African American History Highlights — National Museum of American History, including the soul food movement.
- Cooking Up History — National Museum of American History programming on migration and soul food.
The Knowledge
Where Does Federal Money Go? The Biggest Costs Behind the Budget
Where does federal money go? Part two of our National Debt Explained series examines the biggest expenses in the 2025 budget and how spending connects to government borrowing.
Last Updated on October 13, 2026 by Daily News Staff
The Knowledge | National Debt Explained, Part 2
When discussing debt, ask: Who borrowed the money? That question helps distinguish a family’s finances from the federal budget. Our first episode explained why your credit card balance is separate from the national debt. Now comes the next question: What does the federal government spend money on?
Much of it pays for retirement benefits, health coverage, national defense, public services, and interest on previous borrowing.
Social Security was the largest individual program in fiscal year 2025, costing approximately $1.6 trillion. But combine the major health care programs—including Medicare, Medicaid, and health insurance subsidies—and their spending reached about $1.8 trillion, exceeding Social Security alone. cbo.gov
The figures below cover October 1, 2024, through September 30, 2025.Major expense FY 2025 spending What it supports Social Security About $1.6 trillion Retirement, survivor, and disability benefits Medicare, net $988 billion Health coverage for older adults and certain people with disabilities Net interest $970 billion Cost of servicing publicly held federal debt, after subtracting interest income Discretionary defense $893 billion Military personnel, operations, equipment, and research Medicaid $668 billion Federal contribution toward health coverage and care for eligible people
These are selected expenses, not the entire budget. Medicare spending is shown after premiums and other offsetting receipts. The combined health care total already includes Medicare and Medicaid, so it should not be added to those rows. cbo.gov
The government also supports veterans’ health care, transportation, education, housing assistance, courts, law enforcement, scientific research, disaster response, and environmental protection. Nondefense discretionary spending totaled approximately $980 billion in 2025, covering many of these services. Some funding for these areas falls elsewhere in the budget. cbo.gov
Federal spending falls into three broad groups:
- Mandatory spending: Payments governed by existing eligibility rules and benefit formulas, including Social Security and major health programs.
- Discretionary spending: Funding lawmakers control through appropriations legislation, including most defense spending and many public services.
- Net interest: The expense of servicing publicly held federal debt, minus government interest income. cbo.gov
Interest deserves attention because it pays for borrowing already undertaken. In 2025, net interest exceeded discretionary defense spending. Congressional Budget Office
A program’s cost does not automatically translate into an equal increase in national debt. Taxes and other receipts finance much of federal spending. Social Security and Medicare’s hospital insurance program receive dedicated payroll taxes, while Medicare also collects premiums.
In 2025, federal spending totaled approximately $7 trillion, compared with $5.2 trillion in revenue. The roughly $1.8 trillion shortfall was the deficit, requiring borrowing. Understanding national debt therefore means examining both what government spends and what it collects. cbo.gov
Explore more explanations behind the headlines at STM Daily News, home of The Knowledge.
Sources for this episode
- CBO: The Federal Budget in Fiscal Year 2025 — Overview of spending, revenue, deficits, and debt interest.
- CBO: Mandatory Spending in Fiscal Year 2025 — Breakdown of Social Security, Medicare, Medicaid, and other benefit programs.
- CBO: Discretionary Spending in Fiscal Year 2025 — Defense spending and services including transportation, education, and veterans’ health care.
- CBO: Overview of the FY 2025 Budget Infographics — Highlights the largest expenses and broader budget trends.
Related reading
- U.S. Treasury: Understanding the National Debt — What federal debt represents and how borrowing works.
- U.S. Treasury: Understanding the National Deficit — Explains the difference between an annual deficit and accumulated debt.
- U.S. Treasury: Federal Spending — Additional context about where federal money goes.
