by Katherine Hale
Memorizing scientific names is a rite of passage for naturalists, but some species come with a built-in cheat sheat. Take the Black-Tailed Godwit, a long-legged Eurasian shorebird, which goes by the lyrical Limosa limosa; the Suriname Flat Toad’s alter ego Pipa pipa; and the colorful Harlequin Duck, with the delightfully tongue-twisting Histrioncus histrionicus. All of these are tautonyms—official Latin names where both halves are conveniently identical—bizarre linguistic quirks that can liven up an otherwise dry and technical taxonomic report, and perhaps even generate a smile.
There are no tautonyms in botany. Sensible-minded plant-lovers banned their use from official nomenclature, even retroactively, likely on the grounds that it was too ridiculous and undignified for high-minded, serious science (not to mention lazy). Thus, future generations of naturalists are forever denied the pleasures of declaiming Larix larix or Lablab lablab in their official reports. However, there’s a loophole—creative spellings and minor typographic shifts are permissible. Thus, the cumin in your spice cabinet is Cuminus cyminus, the tropical pigeon pea is Cajanus cajan and the raffia palm is Raffia ruffia–proof that you can obey the letter of the law and still vigorously deny the spirit. Botanists tend to hate these almost-but-not-quite-cheaters and cover them up with a thicket of botanical synonyms in hopes that no one will actually use them. Thus the cranberry, Oyxcoccus oxycoccos was hastily moved to the genus Vaccinium with the blueberries; the tomato, Lycopersicon lycopersicum was shuffled to Solanum; and the desert fruit jujube, Ziziphus zizyphus, is now known in official circles as the more respectable Z. jujuba.
Zoologists, though, have no such scruples, to the point where Bison bison bison–the subspecies of American Bison native to the Midwestern Great Plains– is completely legitimate. Let’s not forget one of our nearest cousins, the Western Lowland Gorilla, Gorilla gorilla gorilla, or the Indian Cobra, Naja naja naja. Try not to laugh when discussing the Ocean Sunfish, Mola mola (although given the fish’s size and appearance, I would argue that “Holey mola” more accurately reflects its true nature and is my preferred binomial). Some creatures, like Iguana iguana, Lynx lynx and Anhinga anhinga, overlap their common name with their Latinate ones for the taxonomic equivalent of a triple hitter. And be careful that you don’t say Bufo bufo (the European Toad) when you really mean Bubo bubo (the Eurasian Eagle Owl).
Ornithologists in particular seem to delight in tautonyms. How else can you explain Crex crex, the European Corn Crake; Sula sula, the Red-footed Booby; or Nycticorax nycticorax, the Black-Crowned Night-Heron? Enjoy the poetry of Temnurus temnurus, the Ratchet-tailed Treepie; Tadorna tadorna, the Common Sheldrake; and Ciconia ciconia, the White Stork. It’s okay to roll your eyes at the Yellow-Headed Blackbird, Xanthocephalus xanthocephalus–“yellowheaded yellowhead” in Latin—or the Whooper Swan, Cygnus cygnus (“swan squared”). And pity the poor Winter Wren, saddled with the decidedly unmusical synonym Troglodytes troglodytes (from the Greek phrase for “cave-dweller”).
Tautonyms enjoyed their greatest vogue in the early days of natural history, and as such, tend to be most concentrated in species described in the eighteenth and nineteenth centuries. The system’s inventor, Carolus Linnaeus, was particularly fond of them, and responsible for such gems as the hawfinch, Coccothraustes coccothraustes and the English partridge, Perdix perdix, (but not, sadly, the Amethyst Gem Clam, Gemma gemma). Linnaeus was also partial to giving creatures the same name in two different languages: thus, we have “heron heron” (Ardea herodias, the Great Blue Heron); “beaver beaver” (Castor fiber, the European beaver); and “sheep sheep” (Ovis aries, the Domestic Sheep).
At their best, tautonyms serve as a clue to the most important characteristic of the species in question, something so obvious or important the taxonomist feels it’s worth repeating. The best example of this is Indicator indicator, the Greater Honeyguide, a bird that regularly leads human hunters to bees’ nests. At their worst, the redundancy comes off gimmicky and strange, like Icelanonchohaptor icelanonchohaptor, an obscure North Dakotan flatworm.
Like all scientific names, tautonyms serve as a unique marker for individual species, ones that stands out from all the others, no matter how nonsensical they sound. The built-in mnemonics that allow tautonyms to linger in the mind after the other “more appropriate” or “dignified” scientific names have vanished into the abyss are only happy accidents of of human language perception. Yet they are undeniably effective. Taxonomists, take note: like them or loathe them, if you want people to remember the scientific name of a species, you could do a lot worse than serve up a tautonym.