The last few years have been tough for gray wolves. Idaho passed a law to kill up to 90% of the state’s wolves. Montana killed 270 in one season. Wisconsin killed about 220 before the species went back on the Endangered Species List. Some 25 wolves killed in the Yellowstone National Park area in 2022 came from the park itself.
Proponents of the cull say too many wolves are on the landscape, and even removing large portions of packs won’t make much impact on overall populations. Short of the mass annihilation of a century ago, they’ll bounce back. They’ll be fine.
But a large study published earlier this year looking at wolves within five national parks across Canada and the U.S. shows that while wolf populations may recover quickly, their social structures don’t. And, the authors argue, the way wolves function on a landscape — how breeding pairs order their packs, how and when they choose to reproduce, for example — is an important part of our natural systems. So the mortality of a single animal could have significant implications.
“You kill the wrong wolf at the wrong time, that pack could blink out or won’t reproduce,” said Doug Smith, recently retired wolf biologist with Yellowstone National Park who co-authored the paper. “Their social dynamics are fragile. We made no value judgment on killing wolves. We’re just saying this is 100% what happens if you do.”
In Wyoming outside of the national parks, where wolves have been managed by the state for the better part of a decade, biologists say they’ve found a way to allow wolf hunting, keep livestock depredations in check and preserve stable pack structures. It’s possible with enough data and attention to wolf management, said Ken Mills, Wyoming Game and Fish’s wolf biologist.
Why packs matter
Understanding what happens when wolves die requires first knowing how wolf packs function.
“Because wolves are social and populations are built on packs, you won’t have a collection of individual wolves. That’s elk and deer,” Smith said. “Wolf packs don’t exist as individuals, they exist as groups in packs.”
Each pack has, in general, three age classes: The breeding pair and their offspring, which are non-breeding adults and pups. Depending on the size of a pack, there could be three to five non-breeding adults. If one of the breeding wolves dies, another one of the adults could step up to breed unless they’re related, in which case a wolf from outside moves in, Smith said.
Some packs will be as small as four or five individuals, others like Yellowstone’s Junction Butte Pack can be as large as 20 — though Smith said that’s uncommon. The average Yellowstone pack size hovers around 10 individuals.
Packs then claim certain territories, and they don’t take those claims lightly.
The biggest killer of wolves is wolves, largely in territorial disputes, said Kira Cassidy, lead author on the new paper and research associate with Yellowstone Wolf Project. Most packs tend to stick to their ranges unless another pack dissolves or becomes particularly vulnerable, usually due to the loss of adults.
Packs naturally break up and re-form even without human-caused mortalities from hunting, car collisions, trapping or poaching. About eight to 10 packs typically occupy Yellowstone, though on average, Cassidy said one dissolves and another forms each year.
When a pack does dissolve, remaining members typically strike out on their own initially.
“There’s usually only a handful [of individuals] left,” Cassidy said. “They become dispersers or lone wolves by default.”
Rarely they may join an established pack — Yellowstone biologists have only recorded an unrelated adult joining an established pack as a subordinate a couple dozen times in the last 28 years. If they’re lucky, these lone animals pair up and find a niche territory they can claim as their own. But more often than not, they’re dead within a year.
Dispersing wolves are more likely to run into humans while seeking food, or they die trying to scavenge another pack’s kill.
“They’re exposed to a lot of mortality out there, much more than just the short time the hunting quota is open,” Cassidy said.
Delicate systems
In the winter of 2021, politics in Montana changed. Lawmakers decided to lift wolf quotas around Yellowstone, opening the area bordering the park to a free-for-all. In Idaho, meanwhile, lawmakers passed a bill allowing year-round wolf trapping on private property, unlimited purchase of wolf tags and any method of take for any wild canines. Wolf killing began in earnest.
Wolves from packs in Yellowstone strayed from the park into Montana and were shot.
As Cassidy watched this unprecedented killing of park wolves, she said, she began to realize this was a chance to determine how packs respond not only to losing individuals, but if it mattered which individuals were killed.
Not long after the park wolves were killed, Cassidy — who came to Yellowstone National Park 16 years ago to study wolves, predominantly their social structures — started noticing differences. Packs like the Junction Butte Pack lost about a quarter of its members, but most were pups and yearlings and the pack stayed intact. Smaller packs like Phantom Lake Pack simply dissolved. But the role of the pack member killed also had a bearing. When the oldest members, one or both of the breeding pair, died, the pack was much more likely to disintegrate.
What she found in Yellowstone was not unique to the system. Combined with parks and protected areas across North America, it showed a pattern. A pack was 27% less likely to survive if any member died of human causes, her report concludes. If a pack leader died, the pack was 73% less likely to make it to the end of the year intact.
Just like in a human family unit, Cassidy said, lose a leader and the void can be tough to fill.
Repercussions across a landscape
What all of this means depends on who you ask. For retired biologist Smith, it means a greater understanding of how a natural system functions, which provides managers the data they need to make informed decisions about wildlife.
For Mills, the Wyoming biologist, it reinforces what he already knew. Higher wolf density outside of Yellowstone has a clear correlation to higher livestock depredations. But keeping numbers steadily around 160 with at least 10 breeding pairs has shown over the last decade to keep livestock depredations to a relative minimum.
In 2016, the U.S. Fish and Wildlife Service killed about 90 wolves for preying on livestock in Wyoming’s trophy game area when numbers were high — due in part to the fact that wolves were on the Endangered Species List. Since then, the number of wolves killed by agency officials because of conflict plummeted: 15 in 2022 and 14 in 2021. Total 2022 mortality in the trophy game area, including hunting, lethal removal and natural mortality, was 53. Even with hunting, packs in Wyoming tend to stay together for an average of six to seven years, Mills said. One pack, the Beartooth Pack, has survived relatively unbroken since 2000.
“The evidence suggests if we manage wolves at high densities, like they were when they were relisted in 2014, then wolf population exceeds carrying capacity,” Mills said. Then, instead of wolves curbing reproduction or dying off from lack of wild food, they started eating livestock.
Mills agrees that hunting can impact pack social structures. It’s why Wyoming structured its hunting seasons in a way that provides opportunity but avoids times when breeding individuals are most vulnerable, he said. Years of data have now shown that keeping most packs intact and wolf numbers below what the landscape will support will maintain wolf packs and help minimize conflict.
Packs can have their own cultures engrained in individual members, Cassidy said, and some packs are more interested in eating livestock than they are elk, deer or other wild prey. If agencies use a scalpel approach, they can eliminate that pack and its replacement may be more inclined to focus on elk and less on cattle.
Mills has also realized that maintaining packs that stay out of trouble keeps Wyoming above the 10 breeding pairs threshold. Consistently kill wolves too close to breeding season or in breeding season and packs may dissolve or fail to reproduce that year.
It’s a balance, Mills notes, but one he feels Wyoming has been able to maintain over the years.
Now, more than a year later, Yellowstone’s overall wolf population has remained largely unchanged around 108 wolves. Packs also increased. Yellowstone lost two packs after the 25 park wolves were killed, and gained four with no signs of those dissipating. And after the 2021-2022 season, Montana reinstated a hunting limit of six around the park.
For Cassidy, pack lineages should be valued by humans as important biological processes just like big game migration routes.
“No one wants a wolf population that is 80% pups, and the best way to get away from that is to help preserve some of the pack lineages,” she said. “Acknowledging our impact is important in understanding how we’re operating in the world and how animals are operating around and beside us, even just that understanding works to a better coexistence.”
Is it possible that elk population is on increase due to more wolves have been killed in 2021-2023. Wolves prefer Elk to dear when the pack size is normal. If the wolf pack size is less than 6 member, it is difficult to prey on large animals, also there is not need for a large kill so they would prey on easier prey, the dear.
Deer are not easier prey for wolves. Mule deer In particular are quite fast, and so are pronghorn. So what does that leave wolves? Elk. Elk are their preferred prey regardless if the pack is 2 members or 20 members. They are inherently easier for wolves to kill because they are slower and can be tired out (wolves can trot/run for hours- but not at high speeds). The season also plays a big roll in how easy of prey elk are for wolves. Elk are easiest to kill fall-spring. By summer they have been grazing on fresh grasses for months and are at peak health.
Excellent report. Shocking how easily packs fail if critical leaders are lost. Colorado has wolves that wandered down from Yellowstone. and a mandate to reintroduce wolves by end of year.
BEST AVAILABLE SCIENCE: Christine’s article alludes to the latest BAS by researchers studying our wolves in NW Wyoming. Wyoming Game and Fish probably already knows much of this research but will always be keen to any new information that can improve wolf management. Our successful wolf management program can only benefit from research which can be applied in the field.
The problem is the wolves are viewed differently depending on the impact on one’s life. To the researcher, it is big money research grants, to the visitor, it is getting to see them “in the wild”, watching them kill is a thrilling plus. To the rancher they are lost sleep, lost dollars as they are up and down all night checking their animals, especially during lambing or calving season. It is having to put down their favorite saddle horse due to the severe injuries from a wolf attack. It is listening to the mamma cow moo crying softly for her baby they killed. It is a severe decrease in income because of the loss. I see no way that both sides can ever agree on the “value” of the wolves, the impact on their lives is too different.
Marion,
My family were sheep and cattle ranchers in the late 1800’s and early 1900’s. The family ranch was handed down to my uncle so I wasn’t raised on it. My grandfather and father talked often of the wolves and bears taking down the animals in their herds. My father told of one bad winter when a group of wolves were following them. He as a child tended the sheepherders camp and told many stories of bears coming into the camp after the sheep and the dogs going after them. These herds were there sole way to provided for their family. Every animals taken down was important to their family’s income and well being. I so understand and respect your point of view.
Then, let ’em find some other job. That’s what the Working Class has done for its entire existence. The high and mighty ranchers are no better. Romanticizing them is nonsense.
Being a rancher is not an excuse to wish wolves death. There are plenty of solutions, some of those being thousands of years old. Take the Turkish for example, who also have livestock and have been living beside grey wolves for thousands of years. They developed the Turkish Kengal Dog. This dog has a bite force of 743psi. It’s an absolute force of domestication and was specifically bred and developed to defend livestock from wolves- and it’s well equipped for the job. If it were me- I’d look into getting myself a few of those dogs before I go out shooting wolves willy nilly.
>>>A pack was 27% less likely to survive if any member died of human causes, her report concludes.<<<
Can the pack differentiate the cause of death? Bullet from 200 yards? Fight with another wolf? Grizzly bear attack? Automobile encounter? This sounds like anthropomorphism to me. I figure they look around and maybe notice someone's missing then move on just like an elk that dies from a wolf encounter or a hunter.
Excellent article. There is a lot more to predator/prey management than forced mortality. Studies like these show that understanding social dynamics can result in an acceptable balance between wolf and human interactions.
AGREE!!
I wonder what the USDA’s professional assasins Wildlife Services and the Wyoming Stockgrowers would have to say about any of this…
I live in the zone where the Beartooth pack is, mentioned by Mills. Zone 1 is adjacent to Lamar Valley and used to have frequent co-mixing with Park wolves.Let’s be clear here. Our hunt zone 1 which always has had the highest quota, isn’t about cattle. WGF told me personally that its about hunting opportunity since our wolves and road distribution make wolf hunting “easier” than adjacent zone 2. If its really only about cattle then why not have “science zones” of no hunting. Or surgical kills on packs that predate consistently on cattle. It worked much better when USFW were doing surgical removals vs. random killing.
I used to hear wolves frequently in the winter. Killing wolves in a hunt is simply about hunter opportunity. But what about my opportunity. Encountering wolves on hikes, or watching them feed on kills was a regular occurrence before the hunt. With fewer wolves and those that are here scared of humans, those opportunities are gone.
Golden eagles, ravens, and bald eagles circled and fed on the carcasses. Those carcasses fed smaller birds and other mammals as well. The valley was alive, not just with wolves, but their presence introduced an electric force that stimulated all the wildlife. Now the winter landscape is emptier, and the cold of winter feels even colder.
Very good article by Christine! I wonder how many people read and understand her science? Respect the wolf!
Don’t the Wolves know they disturb pack stability when they kill each other? Some so-called experts know this, right? What a bunch of non-scientific nonsense. Since they have badly lost the population resiliency debate, now it’s pack dynamics? Ha. Most people don’t understand that natural cycles are constantly bombarded by misunderstood human-caused, well intentioned, but misguided efforts. Colorado is and will be finding this out more and more in the next 10-20 years. Wolves from the South, Wolves from the North and Wolves freshly planted in the middle. That short sighted stupidity is astounding! So, what’s everyone’s favorite Wolf recipe?
While some want more wolves and others want less, Wyoming Game and Fish Departments approach to wolf management is proving to be sound for wildlife, wolves, ranchers and hunters. I think it finds a balance that all can live with, and is a model for other states to perhaps consider. Wolves are not appropriate everywhere, but it’s nice we’ve found a niche they can exist and be managed within, at population levels that are tolerable.
Robert: Agree!! Wyoming has found a compromise which is working for our particular situation. Needless to say, not everyone is happy with the current wolf management by Wyoming Game and Fish and the extremely contentious rhetoric has largely died down – with the exception of Colorado wolves migrating into Wyoming and Yellowstone wolves migrating north into Montana. I still contend this is a national success story and a compromise which most people can accept. Please note the Game and Fish management program is paid for by sales of hunting licenses and angler licenses.
On other matters, Christine wrote a superb article which was very informative and middle of the road in a fashion which shouldn’t stir up the natives. Excellent journalism Christine.
Please support Wyoming Game and Fishes wolf management program – we don’t want to go back to the contentious days – I can see us managing our wolves like this for the next 100 years. As usual, the wolves on the Wind River Indian Reservation are well established and held in reverence by the tribal members. They represent a certain unknown factor with respect to Wyoming wolf populations – and since the Eastern Shoshone nation is a sovereign nation – they are directly under tribal management – they can be expected to flourish under tribal management and their reservation is a huge reservation with primo habitat and exceptionally well watered.
a wolf pack can take down anything on 2 feet or 4 feet.
i don’t think it is the business of anyone when a wolf is killed on private property.
also,what montana,idaho & for that matter colorado due with their wolfs is the business of those states not wyoming’s.
wolf packs are protected in yellowstone they should stick to that territory for hunting.
Do they understand that we humans have set them an absolute territory? “Stick to that territory?”