Colorado is the first state to intentionally bring back wolves by popular vote. But voting was just the beginning. From the ballot box to paws on the ground, this is Gray Territory, a limited series that takes a deeper look at wolf reintroduction and explores the complicated reality of coexistence. 

This transcript is from season five of the award-winning podcast, Laws of Notion, hosted by Kristan Uhlenbrock, Executive Director of the Institute for Science & Policy. For more information and resources from this episode, check out the episode summary page. Enjoy the transcript, and listen to the audio version at institute.dmns.org/gray-territory.

Bonus Episode: Saint or Sinner - An Interview with Wolf Biologist Dave Mech

KRISTAN UHLENBROCK: There is a quote I came across in a research paper from 2012 that I found to be both simple and profound, and that summarizes the complexity of the wolf reintroduction story better than anything I’ve found. The quote is, “The wolf is neither a saint nor a sinner except to those who want to make it so.”

The article was written by one of the most influential wolf biologists, Dr. David Mech, who has authored hundreds of articles and 13 books, including the popular 1970 book, The Wolf: Ecology and Behavior of an Endangered Species. So I felt deep gratitude when he responded to my email saying yes to an interview.

From our podcast Laws of Notion, this is a bonus episode of Gray Territory: The Return of Wolves to Colorado. I’m your host, Kristan Uhlenbrock.

DAVE MECH: I've always been interested, even as a teenager, in carnivorous animals. I used to fur trap, and the carnivores – like mink and foxes and those types of animals – always were harder to catch and more challenging.

My name is Dave Mech. I'm a senior research scientist with the U.S. Geological Survey and an adjunct professor at the University of Minnesota. I've studied wolves since 1958.

KRISTAN: It was during Dave’s undergrad days at Cornell University that he began to apply his teenage fascination with carnivores to research, starting with black bears.

DAVE: We used to live trap bears and put ear tags in them.

KRISTAN: He went on to grad school at Purdue University. That’s where he got his hands into wolf research, when a professor asked him to go to Isle Royale in Lake Superior.

DAVE: As soon as he asked if I would do it, I said yes, and that got me into research on wolves for my PhD. And once I got that, that was kind of a ticket to continuing to work with wolves for the rest of my career.

KRISTAN: Dave finished his PhD in 1962 and published his dissertation on wolves in 1966. That same year, Congress passed the Endangered Species Preservation Act, the first piece of comprehensive endangered species legislation, which would later go on to become the Endangered Species Act. And in 1967, the first endangered species were listed, including two subspecies of the wolf. By 1969, Dave was hired on as a wolf biologist for the U.S. Department of the Interior, where he continues to serve to this day. One thing I wanted to learn from Dave was what he’s witnessed in the evolution of our scientific understanding of wolves.  

DAVE: When I began, we hardly knew what a wolf pack was. There was some literature that seemed to indicate that a wolf pack might be just a family group, but that was not widely known. We did not really discover that and document it until about 1973, that really a wolf pack is basically a wolf family – that is, parents and their offspring.

The wolf has the largest distribution of any land mammal. It's circumpolar, so originally it lived everywhere north of about 10 degrees north latitude around the world. Worldwide, generally, most packs are basically a pair of adults and their offspring. Now, there are some complications to that in some places, especially Yellowstone Park, where there may be two or three families living together as a pack.

KRISTAN: Another understanding of the wolf pack dynamic that has changed with time is the idea related to hierarchy.

DAVE: This has grabbed the public quite a bit. We used to think of the leaders of a wolf pack as the “alpha” animals – that is the idea that wolves had to fight to get to the top of their pack. We found out, over a lot of years of study, that that's not the way wolves form a pack. They form a pack just like a human family does: a member of one pack leaves the pack, disperses, goes out somewhere, and tries to find a member of the opposite sex doing the same thing, mates with that individual, and they start their own pack or family. And so, the idea of calling these leaders “alpha” animals as though they fought to get to the top… we no longer really use that term.

KRISTAN: He reflected on where the “alpha” hypothesis started, how it spread, and his role in that narrative.

DAVE: You have to blame me for that. I wrote a book in 1970. Now that was when I had spent just a few years studying wolves. And in that book, I cited a lot of literature that was already published by other researchers. One researcher was a behaviorist in the 1940s who had thought that a pack was just an assembly of random wolves. And so, when he wanted to study that pack, he got a bunch of unrelated wolves from different zoos, put them all together, and made his own artificial pack. In that pack, the males fought until they had a top ranking one, just like a pecking order in chickens. The dominant male wolf he called the “alpha male” and the dominant female he called the “alpha female.” When I read that literature, that was the best science known at the time. And so, in my 1970 book, I cited that literature. That book ended up being a bestseller and was really the only major book on wolves for 30 some years and was in print until 2022.

During all that time, from 1970 to 2022, whoever read that book learned that wolves had an alpha male and an alpha female. So that's how the whole idea was perpetuated. And it wasn't until 1999 that I published an article refuting all that and indicating that we should not really be referring to the head of a wolf pack as the “alpha male” or the “alpha female,” but rather just the parents of the pack or the breeding male and the breeding female.

KRISTAN: Dave’s research, as well as others’, shows that most packs operate like a family. There is deference and submission that can relate to age and gender, particularly when food is being distributed, such as ensuring young pups are well fed. It can be similar to human parents guiding a family’s interactions and division of labor.

Another shift in knowledge Dave has seen relates to predator-prey dynamics.  A wolf's diet can be categorized as feast or famine. One study documented a wolf going 17 days without a successful kill.

DAVE: Wolves can't just kill anytime they want to. Many people thought that because wolves live in packs, when they attacked an animal, they would usually or always be successful. What we learned in my first study was that their success rate is actually very low. Less than 10% of the times that they try to kill their prey animal do they actually get it.

KRISTAN: Dave observed this low success rate after following a pack of 15 wolves on Isle Royale in Lake Superior, where wolves commonly prey on moose. The success rate can vary based on prey, season, region, or the individual animal, but in general, wolves fail to kill a prey animal more than they succeed.

DAVE: Most of their prey is really large mammals: ungulates, hoofed animals, like deer, moose, elk, caribou, muskox, and bison, that type of thing. So, most of their prey is larger than them, and they try to catch these individuals by traveling around. First of all, all these individuals of these species have various defense mechanisms. Their hooves are sharp or blunt or hard. A lot of them have antlers or horns. So they have defenses. The wolves need to find ways of getting around those defenses.

The wolves travel around daily on an average of 15 to 20 or 25 miles a day. They're traveling around trying to find prey that they can kill.  Well, they might get to one, and the deer or moose or whatever it is senses them and runs off before the wolves can get to them. Or maybe they catch it by surprise, but the animal fights them off.  And then on and on, hour after hour, day after day, until they find one they can finally catch and kill. And the reason they usually end up with it is because it's in some way debilitated, like calves or fawn deer or something, or the very old, or those that have parasites or diseases or some other sort of disability.

Now, when you place all of these wolves in an area where there's also livestock, one of the challenges is that livestock are usually in the same place every day, at least in in the eastern part of the US, where the herds are small. They're kept fenced in certain areas and they're in the same pasture every day. So, wolves there don't have to search far and wide. They can find this prey animal. They know right where it is, day after day. Secondly, when they do find it, those animals don't have the same kind of defenses that the natural prey do, so they're more vulnerable, especially individuals like sheep. And wolves don't distinguish a domestic animal from a wild one. In the western part of the US, where the cattle are roaming over a larger area, there are still enough of them out there that it's not as difficult for the wolves to find them. And when they do find them, rather than the prey running off like an elk or a moose or something might run off, the cattle often just stand there, and they become easier to kill.

KRISTAN: He says a wolf’s behavior doesn’t change that much based on geography. However, one discussion that has surfaced as wolves return to Colorado is what influence they will have on the ecosystem – from prey to plants. It’s known as a trophic cascade.  

DAVE: Generally, the trophic cascade idea is more relevant to more natural areas. So, it's really been developed mostly in Yellowstone, for example, which is a national park where the wolves are protected and everything else, including the habitat, is protected. And if you compare that with Colorado, it turns out that there are so many places in Colorado where the natural habitat has already been disrupted by pasturing domestic animals or a lot of logging, that type of thing. And so, any kind of trophic cascade that wolves might tend to bring about in an area that's already been so changed by humans will be minimal and local, not widespread or anything like that. So, we can't expect the same kind of cascade that might develop in Yellowstone.

But a critical part of a trophic cascade is the relationship between the wolves and their prey. For example, in Yellowstone, the relationship between wolves and elk is that generally, where there are wolves, there are going to be fewer elk. And so with fewer elk, that's going to have an effect on the vegetation because there won't be so many elk to eat so much of the vegetation. In Colorado, that may be the case, but that's only going to be the case in certain places. In some places where wolves are preying more on livestock, there's not going to be a trophic cascade developed there, even just between the wolves and their natural prey. So, the differences here depend on the amount of expansive area that the wolves have to move about in.

KRISTAN: The effects of large predators in complex food-web interactions can be a challenge to measure. Recent research has pushed against a simplified narrative that emerged based on previous research done in Yellowstone National Park – that reintroduced wolves were responsible for large swaths of willow and stream recovery. New research suggests that it’s not that wolves don’t have an effect on the ecosystem, but instead, there are multiple factors.

DAVE: I actually published, in 2012 or so, an article that really warned people that we shouldn't exaggerate these things and should really be sure of what we think we're finding. It's actually one of my students, Dan MacNulty, who's been publishing the most recent challenges to that whole idea. It does seem to be the case that wolves do have an effect, but the earlier studies seemed to exaggerate that effect considerably. It turns out that besides wolves, there's also cougars and grizzly bears and black bears that are also having effects on the prey populations. And there's far more to it than just wolves killing their prey and all of that trickling down to the rivers and all of that. So, I do agree that the trophic cascade idea in Yellowstone is far more complicated than it was originally thought to be, and that the earlier studies and conclusions that were reached were greatly exaggerated. There's still evidence of effects of wolves all down the line, but nowhere near as strong effects as the original researchers originally thought.

KRISTAN: Another nuanced subject in the science of wolves pertains to the idea of subspecies.

DAVE: The whole subspecies concept, not just with wolves, but the scientific concept itself, is controversial. Scientists pretty well agree what a species is, but when it comes down to subspecies, there's a great deal of disagreement. As an example, with wolves in North America, up to at least 1995, science recognized 24 separate subspecies of wolves in North America. As of 1995, they only recognized five. And there are some schools of science that now think it really shouldn't be five, but four. So, that shows the subjective nature of what a subspecies is.

KRISTAN: This recently played out in Colorado. Prior to Colorado Parks and Wildlife reintroducing wolves to the state, they created an agreement with New Mexico, Arizona, and Utah designed to protect the Mexican gray wolf genetic integrity. And in December 2025, one of Colorado’s wolves – a member of the Copper Creek Pack – made its way into New Mexico, where it was then captured and returned to Colorado.

DAVE: You get two schools of thought about the Mexican wolf and whether it should be maintained as a subspecies by preventing wolves from the north from coming into the range of the Mexican wolf. Some scientists think that it's better to allow all the wolves – whether it be from Colorado or Wyoming or even farther north – to mix with those that are being reintroduced into Arizona and New Mexico.

In fact, there are certainly some scientists who even today say, “Just let them all mix.” Let those from Colorado go into New Mexico. And some of those from New Mexico have been trying to get up into Colorado – they've been heading north, and they've had to be caught and brought back south of Interstate 40, which is supposed to be the northern line for the Mexican wolf. And the other school of thought is, “No, protect all of those south of Interstate 40 from any interbreeding with those north of that highway.” So there are those two schools of thought already. And that's just the way it's going to be because of the subjective nature of the whole idea of subspecies.

Some of us are fond of saying “a wolf is a wolf is a wolf,” and that the whole subspecies idea, while it may have some relevance to some in some hypothetical way, that from a practical standpoint, it really doesn't seem to have that much relevance. You can take a wolf from one area and move it to another; it'll still behave like a wolf. There have been wolves that came to Isle Royale in Lake Superior long ago, in the 1940s. They probably were preying on deer on the mainland. But when they got to Isle Royale, the only thing they had to eat was moose. They're killing moose there. Wolves are very adaptable in that respect. All I can say is it's a very subjective area, which gives rise to controversy.

KRISTAN: Science is a human endeavor, so it’s bound to have human fingerprints. Hence why strong methodologies, academic debate, diversity of thought, reproducible results, and many other factors are critical to the whole enterprise, including updating our knowledge when it changes.

DAVE: This is very interesting because it shows the human side of scientists... you know, we're all supposed to be as objective as we can be, but it does turn out that when it comes to the wolf, and other species too, even the scientists have sort of fallen into a couple of different groups. There are some that make no bones about the fact that they're very strong wolf advocates, as well as being scientists, and others who are maybe opposing that type. So from a scientific standpoint, what we've been getting – and it's been shown with the trophic cascade idea – is this battle between two schools of thought in the scientific literature. One group says, “Well, our results show this.” And another group – scientists on the other side – says, “Well, it turns out with the same data, if you look at it this other way, which we think is the better way, no, you're wrong.” That actually ends up having a beneficial effect because between the two of those schools of thought, we're going to get closer to the truth because one is challenging the other.

Science is self-correcting. And we either correct ourselves individually, like I did with the alpha question, or somebody else comes along and challenges it and corrects it. But in the end, science in general ends up closer to the truth.

KRISTAN: Scientific debate is part of the process of furthering our understanding. A challenge comes when translating that information into decisions. 

DAVE: We certainly hope that the decision makers are biologists themselves and therefore can use their own judgments to assess each of these scientific papers that are published that they try to base their management decisions. What that translates to politically is that the professionals are usually civil servants who are in the job because of their background, knowledge, experience, and education rather than for some political purpose. On the other hand, legislators or state legislatures are political appointees or elected by the public. So of the two, when they're of the two types that make decisions, the scientists and the civil servants are more qualified to make the judgements about management than are the legislators that don't have the scientific background. And that happens with wolves in various states: in some cases it's the legislatures that make the decisions; in other states, it's the actual scientists themselves. And so, you can see the differences in the management decisions that are being made.

KRISTAN: And Dave’s thoughts on Colorado’s process so far…

DAVE: We can always say that management plans should be works in progress. But they should also start with a very good basis. And I think the Colorado plan was developed that way and is being applied appropriately. Adaptive management is what we call it, and that's what's being done in Colorado.

KRISTAN: And even though a plan is meant to be adaptive, we know that change can be hard. Especially if we get something wrong.

DAVE: It's called trial and error, and people don't like the error part.

KRISTAN: So I asked if he had any advice or lessons that could be transferred to Colorado.

DAVE: I think the folks in Colorado who are actually on the job working with it are aware of all of the things that are being done in other areas and are applying them to the situation they have in Colorado.

KRISTAN: But when it comes to public perception, there is one shift in thinking that he hopes people will adopt.

DAVE: I think we still need to make sure that people in Colorado, and in general in North America, understand that wolves, although they are a large carnivore and can be dangerous to humans, generally are not. In other words, we should not continue to consider the wolf a danger to everyone all the time. In the last 50 years in North America, there were only two cases where healthy, wild wolves actually killed a person. There are a few other cases where people habituated wolves by conditioning them to human feeding or something, and wolves were less afraid of people. But even then, there are very few cases of wolves attacking people. So, don't consider them something that you have to be afraid of every time you take a step out into the natural world.

KRISTAN: As our season shows, there is often a tension between perception and reality. We don’t often know all the details of a particular issue, or we grapple with our own feelings, values, and sacrifices. The story of wolves is about our relationship to them as a storied species, but it’s also about our relationship to one another, and to nature.   

DAVE: We interfere with nature in so many ways. It's our own nature to interfere in nature. I mean, that's what we do. The minute we build a house somewhere and a road and all that stuff, we've suddenly taken up space that used to be a place for various kinds of wildlife. And then we plant monocultural fields and on and on and on… because of all this, and because of where we are right now on Earth and what all of us have done, the more of the natural lands that still exist, that we can conserve and preserve, the better. I think that we've done enough damage to nature by our very existence that I'm a big advocate of preserving as much wild land and natural areas as possible.

KRISTAN: Laws of Notion is a production of the Institute for Science and Policy at the Denver Museum of Nature and Science. To learn more, visit lawsofnotion.org. I’m your host Kristan Uhlenbrock. This episode was produced by me, Tricia Waddell, and Jordan Marks. Sound design by Seth Samuel. Original music composed and performed by Brett Kretzer with Andy Reiner and by Dr. Joy Adams. For a full list of credits, check out the show notes.

Stay tuned for more exciting extended bonus content.

Episode 5: Beyond the Divide