A significant milestone in the conservation of the American bison has been reached, with the population within Yellowstone National Park now functioning as a single, interbreeding entity. This finding, detailed in a March 2025 study by Texas A&M University researchers, overturns previous understandings that suggested the Yellowstone bison comprised two distinct herds.
The genetic analysis, published in the Journal of Heredity, revealed substantial gene flow throughout the population, effectively dissolving earlier distinctions. Researchers examined genetic data from both summer breeding groups and winter ranges, concluding that Yellowstone's bison should be managed as one cohesive herd. Dr. James Derr, a lead researcher, emphasized the direct impact of this discovery on long-term conservation strategies for this iconic species.
The Yellowstone bison population, which has continuously existed as wildlife in the United States, faced a severe decline during the 19th century, a period known as the "population bottleneck." Numbers dwindled to a mere 23 individuals by the early 1900s due to poaching. A remarkable conservation success story unfolded with the introduction of bison from western Montana and the Texas Panhandle in 1902, which helped stabilize and grow the population. Today, the herd fluctuates between 4,000 and 6,000 individuals, a testament to dedicated recovery efforts.
In response to this new scientific understanding, the National Park Service unveiled a revised management plan in June 2025. This updated strategy aims to maintain the bison population within a range of 3,500 to 6,000 individuals post-calving season. A key component of this plan involves prioritizing the transfer of bison to tribal lands, a crucial step in restoring these animals to their ancestral habitats and supporting biodiversity. This initiative underscores the vital role of collaboration with Native American tribes, strengthening both cultural and ecological connections.
The Yellowstone bison's journey from the brink of extinction to a unified, thriving population is more than just a conservation triumph; it is a profound narrative of resilience and renewal for the American West. The coordinated efforts to manage and conserve this species, particularly the partnerships with Indigenous communities, pave the way for a future where these magnificent creatures continue to roam freely, enriching the prairie ecosystems they have shaped for millennia.