A Name So Nice, They Used It Twice
The American bison has a scientific name that sounds like an echo: Bison bison. It isn’t a typo. When the genus name and the species name are the same word, the result is called a tautonym. Animals can have them; plants, fungi, and algae follow a naming code that rules them out.
That small difference opens a surprisingly entertaining corner of science. There are foxes, lynxes, and even gorillas whose names appear to repeat themselves—and one gorilla whose name says it three times.
First, How Does a Scientific Name Work?
A species’ scientific name has two parts. The first is its genus, a group containing one or more closely related species. The second identifies the species within that genus. Together, the two parts form a binomial name: think Panthera leo for a lion, or Bison bison for an American bison.
Scientific names are generally written in italics, with a capital letter for the genus and a lowercase letter for the species name. So the bison’s name is Bison bison, not “Bison Bison.” The two words match in spelling; their different capitalization tells you which job each word is doing.
The word tautonym makes sense once you take it apart. Tauto- comes from Greek for “the same,” while -onym relates to a name. Put them together and you have, more or less, a “same-name.” The Zoological Code uses tautonymy for this kind of repetition in animal names.
Meet the Animals with Echoing Names
Bison aren’t alone. Here are a few animals that seem to have been introduced twice:
- Bison bison — the American bison. The U.S. National Park Service uses this two-part name for the animal often informally called a buffalo in North America.
- Gorilla gorilla — the western gorilla. Its close relative, the eastern gorilla, is Gorilla beringei: same genus, different species name.
- Vulpes vulpes — the red fox. Its double name applies even when an individual fox’s coat is not the familiar bright red; red foxes occur in other color forms, too.
- Lynx lynx — the Eurasian lynx. Short, sharp, and easy to remember—rather like the animal’s pointed ears.
- Gulo gulo — the wolverine. Gulo comes from Latin for “glutton,” a name tied to the animal’s formidable appetite and reputation.
The repetition can feel comic in English, especially with Gorilla gorilla. But these are working scientific names, not jokes added after the fact. They identify particular species, just as nonrepeating names do. Think of the second word as completing an address: “Which Gorilla?” “Gorilla gorilla.”
If animal vocabulary is your thing, scientific names are only one place to find surprises. The everyday language of animal group names, from a murder of crows to a raft of otters, has its own wonderfully odd history.
Can an Animal Name Say It Three Times?
Yes. Meet the western lowland gorilla: Gorilla gorilla gorilla. The third word names a subspecies, a group within the species Gorilla gorilla. The San Diego Zoo also lists the Cross River gorilla as Gorilla gorilla diehli: same genus and species, different subspecies. Its gorilla guide lays out the distinction.
That extra gorilla isn’t somebody getting carried away with copy-and-paste. It’s part of a three-part scientific name, called a trinomial. In this case, the subspecies name repeats the species name. The result happens to make the whole thing sound like a very persistent gorilla answering a roll call.
The bison can do it too. The plains bison subspecies is Bison bison bison. Two repetitions may catch your eye; three almost demand that you say the name aloud.
Are Scientists Actually Allowed to Do This?
For animals, yes. The International Code of Zoological Nomenclature explicitly says that tautonymy does not, by itself, affect whether an animal name is available under its rules. A repeated name still has to meet the other requirements of zoological naming; saying a word twice does not magically make it an official species.
For plants, fungi, and algae, the rule goes the other way. Their governing code says a species name may not exactly repeat its genus name. It even gives “Linaria linaria” as an example of a designation that cannot be validly published. So if you encounter a plant name that looks like an animal-style tautonym, it’s worth checking before passing it along as an accepted scientific name.
This is an important wrinkle: the difference is about naming rules, not about whether one kingdom has a better sense of humor. The current botanical naming code’s rule on tautonyms is particularly strict about an exact repeat. Names that merely sound similar are a separate question.
Does the Repeat Mean “The Original One”?
Sometimes the repeated name connects to another useful concept: the type species. A type species anchors the name of a genus in zoological nomenclature. In certain circumstances, the code says that if an originally included species has a name identical to the new genus name, that species becomes the type species through “absolute tautonymy.”
That sounds more mysterious than it is. A type species serves as a reference point for a name; it isn’t a prize for being the biggest, oldest, most abundant, or most “typical” member of a genus. Nor should you assume that every repeating animal name tells the same story about how its genus was established. The naming code sets out several ways a type species can be fixed, with an order of precedence among them.
For everyday tautonym-spotting, you don’t need to untangle any of that. Just check the two words of the species name. If they match, you’ve found the echo.
A Tautonym Is Not Just Any Repeated Word
A toddler saying “night-night” is repeating a word, but that doesn’t make it a zoological tautonym. In linguistics, repetition that helps form an expression is called reduplication. You can see the same playful pattern in “bye-bye” and “choo-choo”; baby-talk words across languages offer plenty more to explore.
Nor is a tautonym the same thing as a tautology, which repeats an idea unnecessarily. Bison bison may sound redundant to us, but its two parts have distinct roles: genus first, species second. A tautonym repeats the form of a word inside a naming system; it doesn’t mean scientists accidentally said “bison” twice while trying to describe one.
That’s the charm of the term. Once you know it, a field guide or zoo sign becomes a tiny word puzzle. Is Gulo gulo a mistake? No. Is Vulpes vulpes a fox with a stutter? Also no. They’re tautonyms: perfectly usable animal names with an unmistakable echo—and a reminder that even the most formal language can be fun to say.