User:Evelynpwu/Catalina Island bison herd

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The Catalina Island bison herd is a herd of American bison on Catalina Island off the coast of southern California. In the 1920s to 1930s, several bisons were brought onto Catalina Island for a movie. Over the first 20 years, 23 bisons were moved to Catalina Island. There are a lot more bisons on the island now compared to before. The bison are popular with the tourists and buildings have painted images of bison and bison weather vanes. Over the decades, the bison herd grew to as many as 600. The population currently numbers approximately 150. Biologists found that the bison are not genuinely wild, thus also not purebred; their ancestry includes genes from the cattle, as well as smaller size, different length of legs, jaw length overbite, low fertility, and behavioral problems (such as punctuated walking in tight circles).

Bisons are considered an invasive species in Catalina Island because they were not originally from there. However, because there are a lot more bisons than before, Santa Catalina Island Conservancy needs to make sure that the number of bisons on the island does not exceed the carrying capacity. Sweitzer's team conducted a study on the bison herd to estimate the carrying capacity of bisons on several zones that the bisons spend the most time in. They believe that some of the options to prevent bisons from affecting native species are to restrict bisons to one or more of their zones or to get rid of all the bisons from the entire island.