More than 100,000 grizzly bears once roamed western North America but by the 1920s, only isolated populations were left in the United States outside Alaska. Today, almost all of those populations in the lower 48 are gone
Historically, grizzly bears once roamed throughout the entire western United States south into Mexico, plus Alaska and much of Canada.
Today, they only occupy two percent of their original range in the contiguous U.S., mostly in isolated ‘islands’ of habitat.
Grizzly bears need a large amount of space to thrive
When grizzly bears thrive, other species living in the same areas will generally thrive, too.
Research repeatedly shows that grizzly bears are an effective “umbrella species” (or “surrogate species”) to help focus conservation efforts, especially at broad scales.
Since being listed as an endangered species in the U.S. in 1975, their numbers have gone up, but populations remain isolated.
“Grizzly populations fragment because people like to live, recreate and develop in many of the places that grizzly bears also need,” says Dr. Aerin Jacob, Y2Y’s conservation scientist.
“Without careful planning, the things we do can create real problems for wildlife — like building or expanding infrastructure and housing developments, not taking care of our garbage or educating ourselves about being ‘bear aware’ in recreation. All of that adds up and can make life hard for sensitive carnivores like grizzly bears.”
“One of the reasons we focus on keeping grizzly bears in the Yellowstone to Yukon region is because they are anumbrella — or surrogate — species. Because they have broad habitat needs and share space with so many other species, conserving what grizzly bears need means that we’ll inadvertently help many, many other species too,” says Jacob.
Those species include 16 other large and medium-sized mammals: foxes, coyotes, lynx, and wolves, for example. However, this doesn’t only apply to predators; bighorn sheep and deer, even plants like whitebark pine trees or songbirds can also benefit.
“Y2Y’s efforts include grizzly bears — they help focus our work across such large landscapes because they are so important as an umbrella species across the mountains and foothills,” she says.
Photo: Shutterstock
Diverse needs, big landscapes
Often thought of as mountain dwellers, grizzly bears live in diverse places: the high alpine, river valleys, grasslands, and forest in between. They also have large home ranges, and are often on the move.
Y2Y looks for critical linkages that are either fractured or broken and fix them so animals can keep moving, says Dr. Jacob.
This work benefits six species: western toad, western bumblebee, Suckley’s cuckoo bumblebee, northern leopard frog, pale jumping slug and grizzly bears — but also people.
According to Dr. Jacob, healthy wildlife populations need to include animal movement, so that individuals can disperse, find mates, successfully reproduce, and maintain overall genetic diversity. Keeping the bears connected means they can move, and that means they can breed.
“The alternative is inbreeding and the danger of smaller and smaller grizzly bear populations that can’t withstand future problems. If we don’t restore broken corridors, populations will become more and more isolated until they’re gone,” she says.
Ethyl, the 20-year-old grizzly bear sow left her home range in 2014 to make the move from Coeur d’Alene, Idaho, past Missoula in Montana, eventually ending up in Eureka near Glacier National Park. Read more about Ethyl’s unusual movements.
The biggest threats to grizzly bear populations are habitat loss and human-caused deaths including roads and coexistence issues. The problems are worst for young bears who are still learning to live alongside people.
As bears come across roads that criss-cross their habitat or enter communities, the possibility of problems or interactions with humans rises.
Where there’s overlap with bear habitat, this research shows most grizzly bears over the age of two are eventually killed by people. Almost all are killed within 330 feet (100m) of a road — most are shot, not hit by vehicles.
Adapting to our changing climate
Changing temperatures and extreme weather also means plants and animals will move to more favorable climates. That includes grizzly bears, that need to move and find the cool habitats they are adapted to.
“There are all kinds of wildlife corridors, just as there are all kinds of wildlife,” says Dr. Jacob. “One example is large valleys with gravel-bed rivers. Another is smaller versions, such as wildlife overpasses that, when paired with fencing, can successfully funnel animals to safely cross busy roads.”
“One of the reasons we focus on keeping grizzly bears in the Y2Y region is because they are an umbrella species. Because they have broad habitat needs and share space with so many other species, conserving what grizzly bears need means that we’ll inadvertently help many, many other species too.”
Research on what wildlife need is important, and helps show what’s working. The latest studies show the south and north population of the U.S. grizzly bears are the closest they’ve been in 100 years.
Part of making this recovery a success is ensuring people are ready to share space with grizzly bears. From securing trash and attractants to ensuring bears and other wildlife can cross roads safely, many communities are working to make this dream a reality.
Y2Y will continue to protect and restore current and potential core habitat for grizzly bears throughout the Yellowstone to Yukon region, and facilitate movement via wildlife corridors to ensure healthy populations over the long term. Will you join us?
