Yellowstone National Park is home to black bears (Ursus americanus) and grizzly bears (Ursus arctus horribilis). While grizzlies are iconic, black bears are common within the Greater Yellowstone Ecosystem. Their populations can be substantial, sometimes exceeding grizzlies in certain park regions. Both species play important ecosystem roles.
Yellowstone’s Dominant Bear Species
Grizzly bears hold a prominent position within Yellowstone’s diverse wildlife, representing a significant conservation success story. These large carnivores are a subspecies of brown bear, and the Greater Yellowstone Ecosystem hosts one of the few remaining large grizzly bear populations in the lower 48 states. Their numbers have significantly increased from approximately 136 bears in 1975 to over 1,000 in the Greater Yellowstone Ecosystem by 2024. This recovery led to their delisting from endangered species status in 2016, though conservation efforts remain ongoing.
They are omnivores, consuming a wide range of foods including berries, roots, insects, fish, and carrion, and are known to prey on larger mammals like elk and moose. Their foraging habits, such as digging for roots or preying on ungulates, contribute to nutrient cycling and habitat modification. Grizzlies often range over vast territories, and their presence helps maintain the health and resilience of the park’s natural communities.
Distinguishing Yellowstone’s Bears
Identifying bear species correctly is important for visitor safety and understanding, as both black bears and grizzly bears coexist in Yellowstone. While color can be misleading—black bears can be brown, cinnamon, or even blonde, and grizzlies can range from blond to black—several physical characteristics reliably differentiate them. A prominent feature of grizzly bears is a noticeable muscular hump located between their shoulders, which is absent in black bears. This hump is composed of muscle used for digging, reflecting their foraging habits.
Another distinguishing characteristic is the shape of their facial profile. Grizzly bears typically have a concave or “dish-shaped” profile from their eyes to their nose, while black bears generally have a straighter facial profile. Their ears also differ; grizzly bears possess smaller, more rounded ears in proportion to their head size, whereas black bears have larger, more pointed ears. Furthermore, grizzly bears have long, relatively straight claws, up to four inches in length, adapted for digging, while black bears have shorter, more curved claws, better suited for climbing trees.
Factors Limiting Black Bear Presence
While black bears are present in Yellowstone, their distribution and prevalence can differ from grizzly bears due to habitat preferences and interspecies dynamics. Black bears prefer denser forested areas with ample tree cover for shelter, climbing, and escaping threats. This contrasts with grizzlies, who, while also using forests, are more adaptable and frequently utilize open meadows and valleys for foraging. The Northern Range of Yellowstone, with its lower elevations and longer “green-up” periods, has a higher density of black bears.
Interspecies competition with grizzly bears also influences black bear presence. Grizzlies are larger and more assertive, often dominating food sources and preferred habitats. This dominance can lead to competitive exclusion, where grizzlies displace black bears from certain areas or food resources. Grizzlies have been documented preying on black bears, highlighting the competitive relationship.
Coexisting with Bears in Yellowstone
Bear safety is important for anyone visiting Yellowstone National Park, as all areas are bear habitat. Visitors should maintain a minimum distance of 100 yards from bears and never approach them for photos. Carrying bear spray and knowing how to use it is recommended, as it is an effective deterrent in aggressive encounters. Bear spray should be readily accessible, not stored inside a backpack.
When hiking, travel in groups of three or more and make noise to avoid surprising bears, especially in areas with limited visibility. Avoiding dawn, dusk, and night hikes is prudent, as bears are often more active during these times. Proper food storage is crucial; all food, garbage, and scented items must be secured in bear-resistant containers or hung from provided food poles at campsites to prevent bears from becoming habituated to human food sources.
If an encounter occurs, remain calm, speak in a low voice, and slowly back away without running, as running can trigger a chase response. If a grizzly charges, stand your ground and use bear spray when it is 30-60 feet away; if physical contact occurs, play dead. If a black bear attacks, fight back.