Lee Richardson Zoo

American Bison

AKA Buffalo              

Order: Artiodactyla - even toed ungulates
Family: Bovidae - cattle

Scientific Name: Bison bison bison


DescriptionThe American Bison is a large, heavy bodied animal with shaggy furred hump at shoulders, sloping towards smaller hindquarters.  Bulls have a massive head, covered with thick shaggy mane, normally a beard and dark brown to black pelage.  Both sexes have horns that are relatively short, up-curving and very sharp.  Females are generally smaller overall with a lesser hump and thinner neck.  Weight ranges from 770-2,200 pounds for adults, with bulls in 1,700-2,200 pound range.  Bison are the largest mammal on the NA continent.


Home Range:  The historical range was western Canada, most of conterminous U.S., northeastern Mexico and possibly Alaska.  This is now greatly reduced as most animals are kept on refuges or in captive herds.  The only descendants from originally wild stock and continually maintained are in Yellowstone National Park.  The map exhibits original range and dots are present range.


Habitat Type:  Traditionally is associated with the prairies
but it also occurred extensively in mountainous areas and open forests.


ReproductionMating occurs mainly from July to September and births take place in the spring.  Females are seasonally polyestrous (having more than one period of estrus per year) and may produce young every 1-2 year.  Gestation averages 285 days or 9.5 months, with one calf born.  Calves weigh about 66 pounds at birth, are a rusty brown color, stand quickly, and can run after 3 hours.  Calves are weaned between 7-9 months.  The cow will guard her calf closely and charge intruders.  Young attain sexual maturity between 2-4 years of age.


Diet in WildCompletely herbivorous.  Native grasses and other herbivorous plants.


Diet in Zoo:  ADF-16-cubes, prairie hay, produce.


General InfoThe North American Bison is often called “buffalo.”  Although this is not actually incorrect, it is not specific for only this animal.  There are other members of the buffalo family on other continents (the cape buffalo of Africa, for one). “Bison” is specific to the North American member of the buffalo family. The bison is the largest mammal of the American Continent.  Its closest relative is the European Bison or Wisent. 

Around 1700, approximately 60-70 million bison were living and roamed grasslands of North America in seemingly endless herds.  Severe winters, droughts, prairie fires, bow and arrow hunting by Indians, settlers protecting their cultivated land, and other natural catastrophes that depleted many species of animals failed to diminish these giant bison herds.  However, around 1830, the methodical destruction of the bison population began.  White settlers desired to control the Indians, whose culture was closely intertwined with the bison. Men were hired to slaughter bison to feed railroad crews, and just to slaughter for no use.  Once the railroads were completed, the railroads promoted shooting bison from the train windows as sport for their passengers.  Destruction of southern herds was accomplished between 1871-1875 and northern herds between 1880-1884.   By then, the Indians were starving, and could no longer resist settlement by white man. 

In 1889, it was estimated that the number of wild bison in the United States, including a small herd of 200 in Yellowstone, was only 835.  Fortunately, interested people had been keeping some bison in captive herds, and they were not all destroyed.  A few interested persons met in the New York Zoo in 1905 and were able, at the last minute, to awaken the public’s conscience.  Preserves aimed at helping to repopulate bison numbers were established, and extinction was prevented.  Numbers are now (1986) estimated to be over 55,000 in public and private herds, and in the wild.

Bison have a highly developed sense of smell, able to scent sources of danger over a distance of .6-1.2 miles.  They are able to smell water over 4.2-4.8 miles.  Their hearing and vision are also good.  They do a lot of rubbing of their head and body on trees, branches, etc., and roll in dust wallows to groom skin and fur, and protect themselves from insects.  Despite their build and size, they are extremely agile and quick.  One older female usually leads the herd (females and their young).  Older bulls remain apart from herd except during breeding, and may travel together with other bulls or live alone.  They are good swimmers when they get the chance.  They are very well insulated against winter blizzards and whole herds will stop and stand or lie facing into the wind.  As their fur helps retain body heat, snow can accumulate on their backs without melting from body heat.  Calves, even when raised by people, although playful and easily handled when young, soon become suspicious and wary, and as unpredictable and dangerous as adults.  Many a person has been gored or killed by a bison he raised from a calf and thought tame.  It is said, “The men who know bison best trust them the least.”


Conservation Status:  Listed on IUCN Red List as Near Threatened.