For nearly a century, Catalina Island’s rolling hills and oak-dotted grasslands have been home to one of North America’s most iconic species: American Bison. A dozen or so of these large herbivores were brought to the island in the 1920s to star in a movie. Although their scenes were probably left on the cutting room floor, those original animals spawned a legacy that has continued for more than a century.
Even though the island is not ideal habitat, the bison population has grown dramatically from those first few animals. Animals have been added to the herd to augment its genetic diversity through the years, but most the Catalina Island bison have just done what bison do – bringing the herd’s numbers up to more than 600 in some years. Those numbers are far too many for the island to sustain and periodically the bison were rounded up, with hundreds of young bison shipped to the mainland and various fates among herds on private ranches around the United States.
For the last several years, the Catalina Conservancy has been using a much less invasive method to control the bison numbers: contraception. Female bison receive annual injections and the herd’s size has been reduced to about 150 animals, a number that the Catalina Conservancy feels is much less destructive to the island’s native flora and fauna.