Determining the number of grizzly bears in Wyoming is a complex scientific endeavor due to the wide-ranging and elusive nature of this large predator. Population figures gathered by wildlife managers pertain almost entirely to bears residing within the Greater Yellowstone Ecosystem (GYE), which covers northwestern Wyoming, Idaho, and Montana. These numbers are not a simple census but result from advanced demographic modeling used to track the recovery of this iconic species.
Current Population Estimates and Recovery Status
The most current official estimate for the grizzly bear population in the Greater Yellowstone Ecosystem’s core monitoring area stands at approximately 1,030 individuals. This figure is derived by the Interagency Grizzly Bear Study Team (IGBST), a collaborative group of state and federal scientists. This estimate is a vast improvement from 1975, when the grizzly bear was listed as a threatened species under the Endangered Species Act (ESA) with an estimated low of 136 to 300 bears.
The reported number is an estimated population size, differing significantly from a minimum population count. Historically, minimum counts were based on unique female grizzlies observed with cubs-of-the-year, a method that consistently underestimated the total population. The IGBST has since adopted a sophisticated Integrated Population Model (IPM), which generates a more accurate estimate by incorporating multiple data sources and demographic factors.
This shift in methodology provides a reliable picture of the population’s health and trajectory. The IPM utilizes survival rates and reproductive success, indicating the population has biologically recovered and is stable. The current abundance is more than double the original recovery goal of 500 bears, marking a major conservation success story.
Geographic Distribution and Key Habitats
Grizzly bears counted within Wyoming are part of the GYE population, with the highest densities found in the northwest corner of the state. Core habitat includes Yellowstone National Park and Grand Teton National Park, which provide large expanses of protected wilderness. Surrounding these parks are National Forests, such as the Bridger-Teton and Shoshone, which also hold significant bear numbers.
The population is primarily monitored within a designated Demographic Monitoring Area (DMA), spanning approximately 19,278 square miles. The DMA tracks population abundance and mortality rates to meet recovery criteria. A larger Primary Conservation Area (PCA) provides secure habitat beyond the DMA, including millions of acres of surrounding National Forest land.
The distribution of bears is not static; the species has expanded its occupied range by approximately three times since the early 1980s. About 30% of the estimated range currently extends beyond the DMA boundaries. However, the rate of range expansion has slowed in recent years, with some peripheral areas showing slight retreats as the population reaches the carrying capacity of the most suitable habitats.
Methods Used for Population Monitoring
Scientists from the Interagency Grizzly Bear Study Team employ diverse techniques to generate population estimates. The most fundamental monitoring technique relies on counting females with cubs-of-the-year, which are easily identifiable and provide a direct measure of reproduction. These counts are performed through systematic aerial surveys and opportunistic ground sightings throughout the summer.
The shift to the Integrated Population Model (IPM) represents a move toward comprehensive demographic analysis. This model synthesizes cub counts with data on survival and reproduction rates from radio-collared bears. The IPM allows scientists to project population trends and estimate the total number of bears within the DMA, offering a more robust figure.
Non-invasive genetic sampling, such as collecting hair samples on specialized snags, is a standard tool for monitoring bear populations. This technique allows researchers to identify individual bears and estimate population size without physical capture. This collaborative monitoring effort is maintained by the IGBST, including personnel from the Wyoming Game and Fish Department, the U.S. Fish and Wildlife Service, and other agencies.
Legal Protections and Management Zones
Grizzly bears in Wyoming remain classified as threatened under the Endangered Species Act (ESA), despite meeting biological recovery goals. Management is overseen by the U.S. Fish and Wildlife Service (USFWS). The federal designation requires strict adherence to recovery plans and mortality limits.
Wyoming, Idaho, and Montana have petitioned the USFWS to remove the GYE population from the threatened species list, a process known as delisting. If delisting occurs, management responsibility would transfer to state wildlife agencies, including the Wyoming Game and Fish Department. The state has prepared a management plan outlining how a recovered population would be maintained.
The state management plan includes a framework for setting mortality limits and defines specific zones, such as the DMA, where management actions would be governed. Under proposed state jurisdiction, discretionary mortality, which could include a limited hunting season, would be suspended if the population estimate drops below a specified threshold, such as 600 bears. This demonstrates a commitment to maintaining the species’ recovered status regardless of its federal listing.