The non-native but charismatic Catalina Island bison herd has existed for nearly a century.

A herd of American Bison

American Bison

The American bison , also commonly known as the American buffalo, is a North American species of bison that once roamed the grasslands of North America in massive herds...

 roam, supposedly first imported to California

California

California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...

's Catalina Island

Santa Catalina Island, California

Santa Catalina Island, often called Catalina Island, or just Catalina, is a rocky island off the coast of the U.S. state of California. The island is long and across at its greatest width. The island is located about south-southwest of Los Angeles, California. The highest point on the island is...

 in 1924 for the silent film

Silent film

A silent film is a film with no synchronized recorded sound, especially with no spoken dialogue. In silent films for entertainment the dialogue is transmitted through muted gestures, pantomime and title cards...

 version of Zane Grey

Zane Grey

Zane Grey was an American author best known for his popular adventure novels and stories that presented an idealized image of the Old West. Riders of the Purple Sage was his bestselling book. In addition to the success of his printed works, they later had second lives and continuing influence...

's Western tale

Western fiction

Western fiction is a genre of literature set in the American Old West frontier and typically set from the late eighteenth to the late nineteenth century. Well-known writers of Western fiction include Zane Grey from the early 1900s and Louis L'Amour from the mid 20th century...

, The Vanishing American. Over the decades, the bison herd grew to as many as 600 individuals. The population currently numbers approximately 150. Biologists found that the American Bison

American Bison

The American bison , also commonly known as the American buffalo, is a North American species of bison that once roamed the grasslands of North America in massive herds...

 of Santa Catalina Island are not pure bred; 45 percent have a domesticated cow as an ancestor

Ancestor

An ancestor is a parent or the parent of an ancestor ....

.

The island's bison herd is maintained and monitored by the Catalina Island Conservancy. Although the bison are not native to the island, they comprise an important role in the cultural fabric of Catalina. Therefore, the Conservancy has no plans to remove all the animals from the island.

Controlling the bison population, however, remains important for Catalina's overall ecological health. In the past, bison were routinely removed and sent to the mainland to auction. In 2004, the Conservancy partnered with the Morongo Band of Mission Indians, the Tongva (thought to be Catalina's original inhabitants some 7,000 years ago), and the Lakota tribe on the Rosebud Reservation in South Dakota

South Dakota

South Dakota is a state located in the Midwestern region of the United States. It is named after the Lakota and Dakota Sioux American Indian tribes. Once a part of Dakota Territory, South Dakota became a state on November 2, 1889. The state has an area of and an estimated population of just over...

. A hundred bison were relocated "home" to the Great Plains

Great Plains

The Great Plains are a broad expanse of flat land, much of it covered in prairie, steppe and grassland, which lies west of the Mississippi River and east of the Rocky Mountains in the United States and Canada. This area covers parts of the U.S...

. Recently however, another solution was implemented. The Conservancy initiated a scientific study that determined that a herd of between 150 and 200 would be good for the bison, and ecologically sound for the island. Beginning in 2009, the herd was given animal birth control to maintain the population at around 150 animals.