American Prairie Reserve first reintroduced bison more than a decade ago. They changed the usage of the Reserve’s pastures from seasonal cattle grazing to year-round bison grazing in hopes that bison can carry out their ecological role. Bison are migratory herbivores that need to move across large landscapes, and these movements are thought to have a key impact on grassland biodiversity.
The bison at American Prairie Reserve don’t currently roam free; they live in large, fenced pastures that are between 6,000 and 22,000 acres. Can they still fulfill their ecological role in a place this size? This is one of the questions we hope to answer by tracking their movement.
We also want to understand exactly how bison movement patterns relate to biodiversity. Following individual bison around day and night for an entire year will help us answer these questions. That’s where GPS collars come in.
GPS-tagging a bison
Putting a collar on a bison is no small task. They are large, social animals that live in herds. When one of them is perceived to be at risk, others will come to the rescue. This makes bison handling dangerous, so every step must be planned to ensure the safety of the animal and of the handling crew.
First, we worked with APR’s bison management team to create a detailed protocol for bison handling. The protocols were reviewed by an animal care committee at the Smithsonian, and we received the appropriate permits to capture and GPS-tag bison. The APR team has years of experience, and they are the only people certified to dart the animals and handle the immobilization drugs.