The Conservation Strategy Management Area (CSMA) is an area within which a delisted Yellowstone grizzly bear population was managed with the objective to maintain a stable to increasing population. The CSMA was formalized in the 2007 Federal Rule (72 FR 14866) which removed the Yellowstone distinct population segment from Federal protection as a threatened species under the Endangered Species Act. The CSMA was delineated as the area from within which the Yellowstone grizzly bear population size was estimated and sustainable mortality thresholds and demographic criteria were applied. The decision to replace the CSMA boundary with the Demographic Monitoring Area was first approved by the Yellowstone Ecosystem Subcommittee...
The Distinct Population Segment (DPS) boundary is an area formalized in the 2007 Final Delisting Rule (72 FR 14866) which designates the Greater Yellowstone Ecosystem (GYE) population of grizzly bears (Ursus arctos horribilis) as a single and distinct population from the remaining populations in the lower 48 States. The U.S. Fish and Wildlife Service applied the DPS policy based on the discreteness and significance of the Yellowstone population segment in relation to the remainder of the taxon in the conterminous 48 States.
The Suitable Habitat boundary identifies areas inside the Greater Yellowstone Ecosystem where habitat is deemed suitable for supporting a viable and self-sustaining Yellowstone grizzly bear population into the foreseeable future. The boundary was established by the U.S. Fish and Wildlife Service (USFWS) and formalized in the 2007 Final Rule to remove the Yellowstone grizzly bear from federal protection as a Threatened species under the Endangered Species Act (72 FR 14866 – currently vacated).
Bear Management Units (BMUs) are management areas within the Grizzly Bear Recovery Zone (GBRZ) that were delineated by the Interagency Grizzly Bear Study Team (IGBST) to assist in managing habitat and monitoring population trends of the Yellowstone grizzly bear population. BMU areas approximate the size of the lifetime range of an average adult female and reflect areas of biological relevance to grizzly bears in the Greater Yellowstone Ecosystem (GYE). The GBRZ was divided into 18 distinct BMUs to facilitate monitoring and ensure that adequate habitat and numbers of grizzly bears are well distributed throughout the GYE recovery zone.
The Demographic Monitoring Area (DMA) is the boundary within which all demographic criteria for the Yellowstone grizzly bear population are currently monitored and evaluated. The DMA replaces the Conservation Strategy Management Area (CSMA) as the area within which total grizzly bear population size is estimated and biologically sustainable mortality thresholds are established. All grizzly bear observations and mortalities inside the DMA are counted toward population estimates and mortality thresholds; however, observations outside the monitoring area are also recorded and reported by the Interagency Grizzly Bear Study Team.
Bear management subunits are subdivisions of larger bear management units (BMUs) that make up the Grizzly Bear Recovery Zone (GBRZ) located at the core of the Greater Yellowstone Ecosystem (GYE). Subunits were delineated to assist in the management and monitoring of grizzly bear habitat and population trends. The 18 BMUs comprising the Yellowstone GBRZ were subdivided into a total of 40 subunits to provide greater landscape resolution and to account for seasonal heterogeneity of grizzly bear use patterns within a BMU. Subunits were typically delineated at the scale of the average annual home range of an adult female grizzly bear in the GYE and typically consist of a major drainage enclosed by segments of intervening...