Last week, on May 9, President Obama made it official, naming the American Bison the very first National Mammal. It’s a fitting honor for a creature that has spent its entire existence—some 10,000 years—in North America.
But the American Bison wasn’t the first bison species to roam and prosper in the fertile grasslands of North America. That distinction belongs to the Steppe Bison (Bison priscus), an ancient creature that thrived for millions of years on the Eurasian supercontinent. The ultimate bison ancestor of the American Bison once populated almost the entirety of Eurasia, ranging from as far west as Iberia to Siberia and the now-submerged Beringian subcontinent in the northeast. It shared that vast expanse with the Wooly Mammoth, Wooly Rhinoceros, Musk Ox, Reindeer, and the ancestors of the modern horse.
About 250,000 years ago, it began migrating into North America, stopping first in Alaska and then spreading further inland. It found rich grassland wherever it migrated, survived until at least 36,000 years ago, and gave rise to a new bison species, the first to evolve entirely on the North American continent.
This new species, called the Long-horned Bison (Bos latifrons), took root in the tall grasslands east of the Rocky Mountains. Huge and powerful, these mammalian goliaths stood more than 8-feet tall at the shoulder, weighed more than 4,000 pounds, and had massive horns that stretched up to seven feet (84 inches) from tip to tip. Living in North America for more than 200,000 years, it may have been the largest ruminant species ever to walk the planet.
Long-horned Bison went extinct as recently as 20,000 years ago and might have been one of the creatures the first human migrants to North America encountered after themselves crossing the Beringian subcontinent on foot or paddling down the Pacific coast from Asia. If not, these first colonizers would almost certainly have come into contact with Bos antiquus (literally the ancient Bison) which replaced Bos latifrons and came to dominate the North American continent in population for more than 10,000 years.
Though smaller than its gigantic ancestor, Bos antiquus remained more massive than modern bison. Standing 7.5 feet tall at the shoulders and 15 feet long, it weighed approximately 3,500 pounds and boasted horns about 30 inches from tip to tip. Though the ancient one did not survive as a species nearly as long as the Long-horned Bison, it left many skeletal fossils behind for paleontologists—not only in the West (where it “is the most commonly recovered large mammalian herbivore from the La Brea tar pits” in southern California) but also in the Great Plains states, where numerous “paleo-Indian spear and projectile points have been recovered in conjunction with the animal skeletons” at the “Hudson-Meng archeological site operated by the U.S. Forest Service, 18 miles (29 km) northwest of Crawford, Nebraska.” Thriving for about 20,000 years, the species was one of the few large mammals to survive the last ice age and evolved into the American Bison.
With few predators and a relatively moderate and beneficial climate, the American Bison became one of the most abundant creatures on the continent. Estimated to number as many as 60 million individuals before they were nearly extirpated by professional hunters in the 1800’s, the American Bison once ranged from far northern Canada to Mexico in the west and, in the east, from as far north as New York to Georgia (and possibly Florida) in the south.
Though smaller in size than their ancestors, they remain most impressive creatures and are currently the largest terrestrial mammal in North America. In addition to having a massive head and shoulders, Bison stand nearly six-feet tall and are almost twelve feet long from nose to tail. They weigh as much as two tons, yet they can run up to 40 miles an hour (even outrunning horses) and leap up to six vertical feet. Bull Bison have even been observed jumping approximately 14 feet across cattle guards or delicately tiptoeing across them one bar at a time.
Our National Mammal sustained native American populations—feeding, clothing, and protecting them from the elements—long before Europeans arrived on the continent. They created paths that grew into trails that became the basis for many of the first roads for horses, coaches, and wagons. And as a result of what may have been one of the greatest annual migrations across any continent, the American Bison also helped to shape the ecosystem of North America, not only expanding and enriching the Great Plains into one of the world’s most fertile environments but also cultivating habitat for other species (such as Black-tailed Prairie Dogs) and fostering numerous insect- and seed-eating bird species that followed them along migration routes.
As the Steppe Bison did in Eurasia, the American Bison called the majority of North America and almost the entirety of the United States home. Together, the two bison species—one during the Pleistocene and the other the Holocene—may have been the most influential and dominant ecosystem engineers ever to exist in the Northern Hemisphere of this planet.
You might find the following books and articles about our National Mammal interesting and informative:
“American Bison: A Natural History (Organisms and Environments).” Dale F. Lott and Harry W. Greene.
• Obama Signs Law Making Bison the First National Mammal
• 15 Facts About Our National Mammal: The American Bison
• Basic Facts about Bison
• American Bison [National Geographic]
• Bison Ecology
• Bison [New World Encyclopedia]
• Bison [National Wildlife Federation]
• American Bison [Wikipedia]
• Steppe Bison
• Mammoth Steppe
• Bison Latifrons
• Bison Antiquus