Date

Friday, November 6, 2026, 2:00–2:30 pm ET / 11:00–11:30 am PT

Speaker

Sara Oyler-McCance, Supervisory Research Geneticist and Branch Chief for the Ecosystem and Organismal Ecology Branch, USGS Fort Collins Science Center

Webinar Summary

Once numbering in the tens of millions, American plains bison (Bison bison bison), were driven nearly to extinction with only a few hundred individuals remaining by the late 19th Century. In the early 20th Century, conservation efforts began to restore the species, largely through protection in captive herds that were established from small remnant groups of wild bison remaining in the late 1800s. Plains bison have since recovered to approximately 20,000 animals managed in conservation herds, yet substantial challenges remain. The current conservation herds contain animals representing only a small fraction of historic populations and global genetic diversity, the result of an extreme genetic bottleneck. Moreover, in the early stages of recovery, cross breeding attempts resulted in the introduction of cattle genes into bison when new conservation herds were established. The Department of the Interior (DOI) currently manages approximately 11,000 bison in 19 conservation herds across 12 states. The loss of genetic diversity, coupled with the fact that most DOI bison herds are relatively small and isolated from each other with no opportunity for natural gene flow, raises concerns about maintaining the current levels of genetic diversity. Connecting populations through gene flow (i.e., creating a metapopulation or a group of populations connected though human-assisted gene flow) can minimize loss of genetic diversity, both within populations and across groups of populations. The DOI Bison Working Group has established a framework for a nationally coordinated strategy for DOI bison to support the conservation of genetic diversity. This Metapopulation Strategy provides science-based guidance on how to conserve DOI bison genetic diversity through strategic translocations, while also considering cattle introgression and bison health. In addition to maintaining genetic diversity across DOI herds, this strategy supports the donation of excess bison to Tribes, furthering shared conservation and cultural restoration goals.

Series Info 
Friday’s Findings is a twice‑monthly public webinar series hosted by the USGS Ecosystems Mission Area.