- Grizzlies may be returning to Utah after a recent sighting near the northern border of the state.
- Experts highlight ecological benefits and challenges of grizzly recolonization.
- Concerns include human safety and economic impacts alongside potential environmental advantages.
SALT LAKE CITY — With the death of Utah's last known grizzly more than 100 years ago, there hasn't been much cause for Utahns to ponder sharing the landscape with these long-absent apex predators.
But that may be changing. In April of 2024, a grizzly bear was seen approximately 20 miles east of Utah's northern border. The bear was not relocated and may or may not have crossed the invisible boundary separating Wyoming from Utah since then.
Indicative of grizzly bear recovery efforts, the natural recolonization of their historic range has been cause for concern among some, celebration among others, and a whole lot of honest questions.
The purpose of this article (and others in this series) is to provide expert answers to Utahns' questions, and not make suggestions regarding policy. "That's the needle that has to be threaded by the social/political players," says Darren DeBloois, former game mammals coordinator with the Utah Division of Wildlife Resources.
In response to the previous article and comments made by bear specialist Tom Smith, one KSL.com reader wrote, "I wish Tom Smith would go 'on and on' about the (ecological benefits) of grizzlies specifically in Utah. Other than them eating more wasps and fertilizing the ground with berry seeds, what specifically do grizzlies do that black bears don't, since we don't have enough deer or elk in the state?"
State of Utah's deer and elk herds
Because Utah's landscape is so diverse, there are different reasons why Utah's deer population is currently at around 75% of its objectives.
"Weather has been really difficult," says Dax Mangus, the division's big game coordinator. "That winter of '22-'23 … we had a lot of deer mortality (winter kill) in northern Utah. We're starting to see some good recovery in northern Utah. We're still below where we were, but it's looking more positive."
Conversely, "the last two or three years have been really dry in southern Utah, and so drought is probably the driving factor in the southern half of the state," he said, adding that severe winters and droughts "are the biggest driving factors for deer populations in Utah."
While the weather is "really dominant," says Mangus, other factors are at play. Natural predation is the most relevant to the topic of grizzly bear recovery.
Fortunately, Utah "probably has the most robust survival monitoring research program of any western state," he said.
Based on the Division of Wildlife Resources' monitoring and research, neither habitat nor Utah's current roster of predators — including black bears, mountain lions and coyotes — is currently limiting elk, which Mangus says, "seem to be more resilient in that regard."
Elk are large migratory animals that travel in large herds and can quickly inflict significant damage on commercial crops. For that reason, Utah's elk are intentionally kept at what both Debloois and Mangus refer to as a "socially acceptable number" well below the natural carrying capacity of Utah's landscape.
Unlike elk, however, Utah's deer numbers are not intentionally managed by the state. And "on a handful of units," natural predation could be a limiting factor.
According to Mangus, "(black bear) predation on Utah's deer population is quite low." It's in fact "very rare" for black bears to kill healthy adult deer, he said, but they do kill and eat some fawns, as do coyotes and mountain lions. Some units within the state lose 50% of deer fawns seasonally, and according to Mangus, the majority of that loss is attributed to predators.
That said, fawn mortality varies significantly from year to year based on environmental factors. Just this past season, fawns on the Cache unit enjoyed a 76% survival rate.
When asked whether grizzly bear recolonization would result in additional mortality for Utah's fawns, Smith stated, "It most likely would." However, Smith then added, "I was looking at some studies. You'll find ungulates (hooved animals) in scats of grizzlies, like up in Yellowstone, but it was like 10%. It's not a major portion of what they eat. They're mostly herbivores, really, just with teeth and claws. They're equipped to take meat when they can, but a lot of times they do fine without it."
It is, however, important to note that the influence of apex predators, such as grizzlies, on hooved animals extends beyond predation. Similar to how beavers engineer landscapes to benefit many species, bears are likewise environmental architects.
Ecological benefits of apex predators
"Black bears and grizzly bears don't fill the same niche," Smith says. "Grizzlies are open plains animals. They don't live in forests very much; they cross through them. Grizzlies are interacting with parts of the ecosystem that black bears don't."
Apex predators, such as grizzlies, have what Smith and other biologists refer to as "a top-down effect on the whole food chain below them."
"Obviously, the direct impact on deer and moose, but as we mentioned before, they disperse seeds. And people sometimes pooh-pooh that. But you know what? You can put one Roomba in your house, and it will keep that floor clean. You put a population of grizzly bears (on the landscape) — they are out there spreading seeds all the time, everywhere. We can kind of dismiss it, but it's huge."
Before focusing on bears, Smith studied elk and mountain sheep, which go to what he calls "extraordinary lengths" to find micronutrients like "calcium and phosphorus." Grizzlies spread those and other nutrients through the system, linking predators like grizzlies "directly to ungulate health." Other ecoservices provided by grizzlies include aerating soil and the upslope transportation of nitrogen.
Smith notes that these ecoservices do not mean there aren't also issues on the "counter balance," including concerns about human safety, economics and more. However, he says, "We know that there are many positive benefits. And I think that part of the problem with bears is people just focus — I think unnecessarily — on the negative, as far as the fact that there are some conflicts with those animals."
While Smith is not making policy recommendations, he adds, "Let's at least be informed when we make our decisions."
For a more comprehensive understanding of this complex issue, watch the full interview with Tom Smith linked above.
