Yellowstone Elk’s response to Wolves

Yellowstone Elk’s response to Wolves: Female Yellowstone Elk Courtesy & Copyright Bonnie McDonald
Female Yellowstone Elk Courtesy & Copyright Bonnie McDonald
Arguably the most scientifically-important (and controversial) elk herd in the world, because it has been scrutinized and studied the longest, is in Yellowstone National Park.

The first professional study of the herd was started in 1916 and the herd has been at the center of debates about the forces that shape wildland ecosystems ever since.

Yellowstone Elk’s response to Wolves: Spring Elk Herd Courtesy Utah DWR, Tom Becker, Photographer
Spring Elk Herd
Courtesy Utah DWR, Tom Becker, Photographer
In addition to providing insight into ecosystems, the Northern Yellowstone elk have been an important source population for restoring other elk herds in the United States and Canada where they were eliminated during the late 1800s. Many elk herds in North America trace their ancestry to translocated elk from northern Yellowstone.

Yellowstone Elk’s response to Wolves: Utah Cow & Bull Elk Courtesy & Copyright Greg Sheehan
Utah Cow & Bull Elk
Courtesy & Copyright Greg Sheehan
The herd has a seasonal migration route that stretches from the Paradise Valley in southwest Montana to the southern boundary of Yellowstone National Park – a distance of 80 miles.

Prior to the Yellowstone’s establishment in 1872, market hunting decimated the elk herd, reducing it to a few thousand animals. Through the 20th century the population gradually grew and in 1994 it reached a peak of over 19,000.

Yellowstone Elk’s response to Wolves: Collared Yellowstone Wolf Courtesy & Copyright Matt Metz
Collared Yellowstone Wolf Courtesy & Copyright Matt Metz
A year later, the first of 41 grey wolves were reintroduced to Yellowstone.

People wondered what impact these wolves would have on the Yellowstone herd since elk are the main source of food for the canines.

Dan MacNulty, associate professor in the Department of Wildland Resources in the Quinney College of Natural Resource at USU, who has been studying Yellowstone wolves for the past two decades said, “people were concerned wolves were inducing a landscape of fear which was changing the way elk were using their habitat.”

They imagined the poor creatures hiding in less than ideal habitats because they had been chased off by the wolves.

However, studies conducted by MacNulty and others have since revealed that elk continue to maintain regular access to all their usual habitats irrespective of wolves. In one recent study, for example, MacNulty and his team found adult female elk established and maintained winter home ranges without regard to several measures of wolf predation risk including the density of wolves and the risky areas where wolves often kill elk.

Yellowstone Elk’s response to Wolves: Female Yellowston Elk Defending Herself From a Wolf Courtesy & Copyright Robert Landis
Female Yellowston Elk Defending Herself From a Wolf
Courtesy & Copyright Robert Landis
Elk coexist with wolves in a variety of ways. One way is elk use the riskier areas of the landscape when wolves are resting, which is in the afternoon and, surprisingly, at night. Wolves don’t have ideal vison for nocturnal hunting, so they often settle down after sunset and resume hunting at dawn. These nightly lulls in wolf activity allow elk to graze the open grasslands in relative safety.

But even when wolves are on the prowl, elk don’t seem to go out their way to avoid them. MacNulty’s recent study found the rate at which elk encountered wolves was no different from what was expected if elk simply ignored wolves. This is possible because elk often survive their encounters with wolves, owing to their larger size, aggressive demeanor, and herding behavior. As a result, elk seem to place greater emphasis on finding food than on avoiding wolves.

The emerging picture is that the effect of wolves on the northern Yellowstone elk herd is defined by wolves eating rather than scaring elk. How much this consumptive effect actually matters for elk population growth is the focus of ongoing research. One clue that it may not matter too much is the elk population has been steadily growing since 2012.

MacNulty cautions that we should recognize the complexity of the Yellowstone ecosystem and resist the urge to jump to conclusions, and instead rely on patient data-gathering to test what may seem obvious.

Nature can be full of surprises.

This is Shauna Leavitt and I’m Wild About Utah.

    Courtesy & Copyright Dan MacNulty
    Courtesy & Copyright Tom Becker
    Courtesy & Copyright Greg Sheehan
Audio: Courtesy and Copyright Kevin Colver
Text: Shauna Leavitt

Sources & Additional Reading

Hillyard, Traci, MacNulty, Dan, Yellowstone Elk Don’t Budge for Wolves say Scientists, Utah State Today, Utah State University, Tuesday, Mar. 26, 2019,

Hillyard, Traci, Cotterill, Gavin, Hidden Costs of Disease to Greater Yellowstone Elk, Utah State Today, Utah State University, Monday, Oct. 29, 2018,

Hillyard, Traci, MacNulty, Dan, Kohl, Michel, Yellowstone’s ‘Landscape of Fear’ Not So Scary After All, Utah State Today, Utah State University, Tuesday, Friday, Jun. 22, 2018,

Elk, Yellowstone National Park, US National Park Service, US Department of the Interior,

French, Brett, Famous Yellowstone elk herd rebounds two decades after wolf reintroduction, tar-Tribune Feb 3, 2018,

Spring Testosterone

Spring Testosterone: Male House Finch Courtesy US FWS Gary Kramer, Photographer
Male House Finch
Courtesy US FWS
Gary Kramer, Photographer
Love is in the air! While shoveling snow, it seems a bit ludicrous to say “spring has arrived”, but here it is! I first noticed it 3 weeks ago when a burst of house finch tumbling notes filled the vapors. That was followed by a robin dusting of some rusty phrases which will soon be heard across the mid-latitudes of N. America.

What is one to think of such outrageous behavior as the snow continues to fall and the thermometer dips well below freezing? In one word-testosterone! This magical chemical is surging once again entirely dependent on the ratio of daylight to dark which has changed to such a degree that life helplessly submits to the urge for love.

Boxelder at Court of the Patriarchs,  Zions National Park Courtesy NPS Amy Gaiennie, Photographer
Boxelder at Court of the Patriarchs,
Zions National Park
Courtesy NPS
Amy Gaiennie, Photographer

Even plants are getting in the mood due to hormonal change in response to increasing length of daylight. If I were still teaching science at Logan High we would be tapping a spile into a box elder tree to catch the dripping sap and boil down on the Bunsen burner to delicious maple syrup. When we began this activity 32 years ago March was the month. It gradually changed to mid-February as the winter season shortened.

Death Camas Bryce National Park Courtesy US NPS
Death Camas
Bryce National Park
Courtesy US NPS
I’m guessing the tiny pink flower of stork’s bill geranium and yellow of biscuit root is already blooming beneath the snow on south facing slopes. Death camas leaves are beginning to poke through moist soil.
Snow geese and tundra swans are beginning to populate our open waters with sandhill cranes and many other species of waterfowl soon to follow.

Mountain Bluebird Pair Courtesy & Copyright Milt Moody, Photographer
Mountain Bluebird Pair
Courtesy & Copyright Milt Moody, Photographer
In the heavens you may see golden eagles performing their talon locked tumbling courtship death plunge, and paired ravens cavorting in mid-air. Outrageously beautiful Mountain bluebirds begin decorating fence posts in the countryside. Clark’s nutcrackers are beginning their migration to ridgetops for nesting activities.

Great horned owls present a special case. Their hoots reached a fevered pitch during their January courtship period. Nesting begins in February but no nest building needed. They take the easy out by occupying other raptor nests, especially red tail hawks, crows, or a handy ledge. They are fierce defenders of their young and have caused injure to clueless humans who approach to near. The family unit will remain together into the fall season.
Coyotes and fox are in full courtship mode showing overt affection. Parents of both of these wily canids help with den preparation and rearing pups born a few months later. Both are common in native legends for the cunning and trickery.

“If the day should ever come when one may camp and hear not a note of the coyotes joyous stirring song, I hope that I shall long before have passed away, gone over the Great Divide.” Earnest T. Seton, American naturalist, author, activist and father of the Rocky Mountain N.P.

This is Jack Greene and I’m Wild about Wild Utah!


    Male House Finch, Courtesy US FWS, Gary Kramer, Photographer
    Boxelder at Court of the Patriarchs, Zions National Park, Courtesy NPS, Amy Gaiennie, Photographer
    Death Camas, Bryce National Park, Courtesy US NPS
    Mountain Bluebird Pair, Courtesy & Copyright Milt Moody,
Audio: Contains Audio Courtesy and Copyright Kevin Colver
Text:     Jack Greene

Sources & Additional Reading:

Körner, Christian, Plant adaptation to cold climates, National Center for Biotechnology Information, U.S. National Library of Medicine,

Have BoxElder Maple Trees? Make BoxElder Syrup! Quirky Science,

The Henry Mountains’ Bison Herd

American Bison Courtesy US FWS Ryan Moehring, Photographer
American Bison
Courtesy US FWS
Ryan Moehring, Photographer
The Henry Mountains of southeast Utah are famous for being the last mountain range in the contiguous United States to have been officially mapped. Indeed, before they were mapped, they were often referred to as the “Unknown Mountains.” Another relative unknown detail about this range is that it harbors one of only five genetically pure, free roaming bison herds on North American public lands.

In 1941, a seed herd of 18 American Plains Bison (B. b. bison) were transplanted from Yellowstone National Park to the arid desert of Utah’s Robbers Roost. A year later, five more bulls were introduced to the herd in hopes of sufficiently diversifying the gene pool and sustaining the herd. The bison must not have found Robbers Roost as appealing as Butch Cassidy had, though, because this new Wild Bunch set out for literal greener pastures that very same year.

The small herd forded the Dirty Devil River and travelled southwest toward the Burr Desert. The herd stopped here for a while, enjoying their newfound buffet atop the Aquarius Plateau. 21 years later, though, in 1963, the still small herd grew tired of the desert and abandoned it altogether for the higher, more verdant snow fed meadows of the nearby Henry Mountains. Here, the herd thrived and quickly swelled in numbers.

Today, the herd’s population is estimated to be between 300 and 400 animals, which ecologists and wildlife biologists regard as the maximum carrying capacity of their Henry Mountain range. The Utah Division of Wildlife Resources has responded accordingly. In an effort to perpetuate the health of the herd and their range, the DWR began issuing “Once-in-a-lifetime” permits to hunters hoping to fulfill not only a tag but also a burning sense of adventure. The Henry Mountains, after all, were mapped last for a reason. They remain one of the most rugged and remote places in a state known for its rugged and remote places.

Fittingly, quite unlike their more quintessential Plains Bison brethren, the Henry Mountains bison can be found almost anywhere in the Henrys between the desert lowlands and timberline. Apparently no one has told the herd that Plains Bison don’t typically like high elevations or steep mountain slopes. This unique proclivity of the Henry Mountains herd to cast off behavioral stereotypes works in their favor when hunting season rolls around and they abandon the high, open meadows for steep, wooded canyons and thick groves of aspen and evergreens.

This highly adaptive nature unique to the Henry Mountains herd made it an obvious candidate to serve as a seed population in early 2010 when 39 individuals were transplanted from the Henry Mountains to the Book Cliffs along the Utah-Colorado border. These 39 animals were to serve as a genetic supplement to a relatively new herd first reintroduced to the Book Cliffs by the Ute Indian Tribe in 1986. The now 600-strong Book Cliffs herd is well on its way to reestablishing the American Plains Bison’s historic range in the Book Cliffs.

The story of the Book Cliffs and Henry Mountains Bison give us reason to hope that one day soon, the American Bison might reclaim its territory, a historic range that once ran from Alaska through the Canadian territories and the Great Plains to the Eastern Seaboard and the Gulf of Mexico. And, if so, the role the Henry Mountains herd will play in that expansion may be a significant one.

I’m Josh Boling, and I’m Wild About Utah.


Photos: Courtesy US FWS, Ryan Moehring, Photographer
Audio: Includes audio from
Text: Josh Boling, 2019

Sources & Additional Reading

Utah’s Book Cliffs Herd, Bison Bellows Series, National Park Service, June 30, 2016,

How scientists brought bison back to Banff, National Public Radio, Feb 28, 2017,

Buffalo (Bison) on the Henry Mountains, Capitol Reef Country, Wayne County Tourism,

Henry Mountains,,

Bison Unit Management Plan, Unit #15 Henry Mountains, Utah Division of Wildlife Management,

Gilman, Don, Rare, genetically-pure bison found in Utah’s Henry Mountains, St George News, Jan 12, 2016,

Henry Mountain Outfitters, HuntersTrailhead,

Brian, Jayden, Utah Henry Mountain Bison Hunts, Bull Mountain Outfitters, LLC,

Henry Mountains bison herd, Wikipedia,

Wild Cats

Bobcat in plants Courtesy US FWS Steve Hillebrand, Photographer
Bobcat in plants
Courtesy US FWS
Steve Hillebrand, Photographer
I remember well my first encounter with a wild cat. I was sitting in a deer stand beneath a cross-country powerline, at the edge of a meadowed thoroughfare the whitetails frequented. Dusk was settling in—nearly time to go—as the trees opposite me began to rustle. With a few minutes of legal light left, I readied my trigger finger; but instead of a deer, a bobcat exited the woods. I was shocked. This—I had not expected. I watched as the cat looked left, then right, then straight at me, making eye contact. There was no reason I should have been noticed. I hadn’t made a sound, hadn’t moved in nearly three hours save the scanning of my eyes and the slight rise and fall of my chest with every breath.
Bobcat Public Domain image courtesy US FWS National Conservation Training Center
Public Domain image courtesy US FWS
National Conservation Training Center
Still, I had been found. The cat ambled slowly but with purpose toward the ladder that connected my seat to the ground, stopping a few meters away. He or she never broke eye contact. Neither did I. I’m not sure why. Instinct, perhaps. I would learn many years later from a man who had stared down a mountain lion from a meter away that you never break eye contact with a big cat in the wild. Never. I have no idea how long we sat there together. Minutes? Seconds? Hours? It was fully dark when the animal turned to leave—so dark I had lost the pattern of its coat in the shadows. I never saw where it went; but I’ve been enamored with wild cats ever since.

Bobcat Courtesy US FWS Gary Kramer, Photographer
Courtesy US FWS
Gary Kramer, Photographer
The landscapes that have shifted and morphed and been politically bordered into what is now the state of Utah has been populated by wild cats since at least 40,000 years ago. During the Pleistocene Epoch’s last ice age, the infamous saber-toothed cat roamed Utah’s glacier-clogged crags. Bones of the saber-toothed species known as Smilodon have been unearthed in Utah, most notably from the Silver Creek site near present-day Park City. Smilodon, with its legendary curved, saber-like canine teeth, was a fearsome hunter of ancient Utah’s mega fauna like the mastodon and wooly mammoth; but when the glaciers receded and the Earth began to melt, the mega fauna couldn’t adapt, so Smilodon had nothing to hunt.

Smilodon gave way through the millennia to the smaller but no less impressive cats that occupy Utah’s crags and hills today—the bobcat, the Canada Lynx, and, of course, the famous mountain lion.

Big cat footprint Courtesy & Copyright Josh Boling, Photographer
Big cat footprint Courtesy & Copyright Josh Boling, Photographer
It hasn’t been too long since that spring evening in the canyons of southern Utah. We had just rappelled into a small grotto where, at the bottom, there was an ephemeral pool. The sand was already wet with little droplets along the edge, a footprint here and there leading away—the way we would take—down the only path toward home. We chattered more loudly, making ourselves known, as we proceeded. Then we’d grow quiet again, eyes sweeping here and there, secretly hoping we would get a peak of the lion as it sauntered away from us. We never did, but it was there.

I’m Josh Boling, and I’m Wild About Utah.


Photos: Courtesy US FWS
Big cat track photo courtesy and copyright Josh Boling
Audio: Includes audio from North Sounds, Inc.
Text: Josh Boling, 2018

Sources & Additional Reading

Golla, Julie M., “Urban Bobcat (Lynx rufus) Ecology in the Dallas-Fort Worth, Texas Metroplex” (2017). All Graduate Theses and Dissertations. 6857.

Bauman, Joe, Ice Age in Utah, Deseret News, Dec 3, 1997,

Larese-Casanova, Mark, Mountain Wildlife Field Book, Utah Master Naturalists,

Fossils on Reclamation Lands Provide a Glimpse Into the Past,

Ice Age Animals of Utah, Utah Geological Services, A division of the Utah Department of Natural Resources,

Strand, Holly, Mountain Lion, Wild About Utah, Mar 4, 2010

Greene, Jack, My Cougar Encounter, Wild About Utah, Jan 16, 2017,

Murie, O. J. (1982). Animal Tracks. Peterson Field Guides. New York, NY: Houghton Mifflin.