On April 30, 2026, a white bison calf was born at Neal Smith National Wildlife Refuge in Iowa. On the evening of June 16, 2026, a refuge staff member reported that the calf had died. This is a sad outcome and not what anyone hoped for. The white bison calf was quickly beloved by our community and many visitors enjoyed seeing the calf this spring.
The U.S. Fish and Wildlife Service has received the preliminary results from the postmortem assessment of the white bison calf. While the final lab tests are still pending, early findings show the calf had skin lesions in multiple areas as well as internal stomach lesions. The infections that caused these lesions may have prevented normal digestive functions and may have led to sepsis, which is when harmful germs spread through the bloodstream. These initial findings are consistent with animals that are born with weak immune systems.
As we review these findings, it’s also important to understand how wildlife is managed on national wildlife refuges. The National Wildlife Refuge System is built on the idea of letting nature take the lead. That means natural events—such as births, illnesses, and deaths—are allowed to occur with as little human interference as possible. These natural processes help keep ecosystems balanced and healthy over time.
Because of this approach, not every outcome is something we can control, even with careful monitoring and care for the land and habitat. But each event, even the difficult ones, is part of how a wild population grows, adapts, and stays resilient.
