A petition to list all plains bison in the USA as “threatened” was denied. The USF&WS made a negative 90-day finding. Therefore, it announced, “We are not initiating a status review in response to this petition.” The 11-page finding can be found at 76 FR 10299, February 24, 2011.
The petition by two private individuals was filed on June 22, 2009. For those interested in the African lion listing proposal; this provides some idea of how long it takes for the agency to make a 90-day finding - 20 months.
The Agency found the “population trends of wild plains bison in conservation herds appear to be stable to increasing in recent years. The number of conservation herds also continues to increase…. The current population of wild plains bison is estimated to be 20,500 animals in 62 herds.” Apparently there are also 400,000 to 500,000 in 6,400 commercial herds. Nearly all are stable or increasing.