Latest Studies On Yellowstone National Park's Wolf Packs Shows Stable Population
Editor's note: Contributing writer Beth Pratt recently caught up with Douglas Smith, who has been studying wolves for more than 30 years and who currently leads the wolf project in Yellowstone National Park. He is the co-author of Decade of the Wolf, a book that details the historic wolf restoration in Yellowstone. The two talked about the current status of wolves in the park and their impact on elk populations.
You are the middle of your annual winter research—what are you finding initially?
The wolf population is pretty stable compared to last year. We had 94 wolves in the northern range in 2007, but now we have 38. We saw a big drop for the two consecutive years prior, but essentially no change in the population this year.
Do you think the population has stabilized?
To a degree, and I guess the message from this trend is “less is more.” The wolves for many years overshot the capacity of the ecosystem, and now we are seeing a balance—a balance of all parts not just wolves. When wolves weren’t in Yellowstone the system was out of whack because there were tons of elk and tons of coyotes and other things suffered as a result. Now there’s greater balance among both plant and animal species.
I imagine this is more what Yellowstone was like before it got changed because of European humans. From research we know when you have a full suite of carnivores, you have lower densities of the main prey species, but you also have really resplendent and luxurious vegetation. Because without predators the herbivores are mowing it all down. In the lower 48 we eradicated wolves before we knew what they did, so we have these erupting game populations that exceed what a healthy ecosystem can sustain.
Many have been critical of the wolves for reducing the elk population and don’t see a decrease in elk as a positive development.
It’s incredibly painful dealing with people who don’t like wolves and say they have devastated the elk herd. And it’s difficult to talk to people who just want Yellowstone to be an elk farm. Yes, with carnivores you have fewer animals to hunt. But this is the way it was in Yellowstone before we interfered and we need to know what it was really like and be honest about it. I’m not saying I am in favor of predators being everywhere, but what’s happening here is a system being restored to balance.
When we start killing predators because we want more animals to hunt, it becomes agriculture. It’s like spraying weeds. Is that what we want the forests and the landscapes of the West to be, a big farming operation? An author I read recently said when wolves go, wilderness goes and I agree. I don’t want the world to be so highly manipulated that we have no place where wild nature can just be.
I hunted elk for four days this year and I didn’t get one and I am not disappointed. So I had four great days in the wilderness hunting and I did not take a shot. And I will do it again next year and if I don’t get one I am okay with that. I don’t live on elk. It’s a recreational pursuit. I don’t need to kill an elk to feed my family and I would say there are very few people who do.
Do you think wolves are the only reason the elk herd in Yellowstone has decreased?
Elk have come down for many reasons, wolves being just one of them. Yellowstone is a multi-carnivore system, one of the most beautiful and rich in North America. You go to Alaska and northern Canada you don’t have the carnivore richness you have here in the park with cougars and bears. Cougars have a higher per capita kill rate than wolves, and bears take a ton of calves. Also contributing toward the decline is that the state was managing for fewer elk. They were shooting cows like there was no tomorrow.
The third reason for the decrease that’s a harder thing to put our finger on is climate change. I think climate change makes elk more vulnerable to wolf attack.
Can you expand on this—the connection between climate change and elk predation by wolves?
The best answer to this question—it’s all changing here because of climate. The landscape is changing and it’s affecting elk and wolves are responding.
This is evolving research, but there is an interesting study going on east of the park by a graduate student at the University of Wyoming. We’re looking at the same trends, but we’re a little bit behind him. What we are both finding is that the annual “green-up” [when snowmelt gives way to vegetation] is starting earlier and it’s also burning up the mountainside a lot quicker.
The link to elk is this—when new vegetation is growing it’s the most nutritious for elk. At the start of spring elk are existing on fumes. To restore their fat they need quality vegetation for a sustained period. In the past the green-up would extend until August and the elk had a lengthy period to restore their condition. Now that time period is being reduced by up to 40 percent.
Winter is just tough for an elk. I sometimes wonder why evolution made it so tough—it’s bizarre. Elk head into winter with a fat content that will vary from 10 to 20 percent. If it’s less than 10 percent they can’t even conceive a pregnancy and they probably are not going to make it through the winter. If they are at 20 percent they will probably burn through all of that fat during a long winter like this one. They are eating, but it’s maintenance eating—to survive they are really relying on reduced activity and fat reserves. And if they have a calf on top of that, their energy reserves really get depleted, and it takes a long time to build back up.
So global warming is altering this green up, and they can’t recharge as well. Now this is all in the hazy phase of research, but what they are finding east of the park is the elk are adapting by not reproducing annually. Typically older elk would switch off, but 90 to 95 percent of younger elk in the past reproduced every year. Now we are seeing rates of only 60 percent of young migratory elk being pregnant.
Is there a difference in the findings with migratory versus non-migratory elk?
Non-migratory elk, which years ago did not exist, stay all year in alfalfa fields at low elevations. And they are doing great--they are booming. They can’t kill enough of them.
The elk that migrate into Yellowstone are not doing well at all. One reason is that they are exposed to a lot more predators in the summer, but the other factor is this relationship to changing vegetation. So you have to ask the ultimate question—why do elk migrate then? These elk migrated decades ago because it was a good thing to do and the green-up was working. But what used to work for elk and essentially was a really good strategy, isn’t anymore. And that to me is really disturbing. This strategy is hardwired in elk and they are still doing it and it’s failing them.
They may get a break this summer, as I think this is not going to be a year like I just described in the research, unless it turns hot soon. In 1996 and 1997 we had big snow years, but it turned hot and there was not a gradual letting out of the snow. Instead the Yellowstone River overnight was a chocolate, frothing mess, which isn’t normal either.
If it lets out slowly this spring and summer, it will resemble the pattern we had decades ago. But the problem is next year is anyone’s guess -- we can’t rely on normal cycles anymore. This winter was the snowiest in decades, while last winter was anemic, all the snow came in April and May. It’s the unpredictability that’s the problem. We used to have an average with little blips here and there. Now it’s all across the board and animals can’t adapt.
What’s your opinion on listing the wolf as an endangered species?
I have this idea that being able to hunt wolves increases tolerance of them and lowers resentment. At the end of the day for me, that’s better than keeping wolves on the list when animosity towards them is high.
I think it’s fair to say we want to vigorously protect wolves in some places. But I’m very much in favor—for a lack of a better way to talk about it— of zonal management. We can designate areas where we are not going to harvest wolves. And in other areas where wolves are clearly hard to live with because people are trying to make a living, you have some harvesting. This idea of social tolerance increasing by a regulated hunting season is where I think we need to go. It’s a very modern position, but I think we really need to be modern.
Any surprises in your research this year?
A really cool finding that we’ve discovered is that black wolves have longer survival times than grey wolves. For female wolves it’s double the life span. For a black female wolf the average age of death is 8, while for a grey female wolf the average age of death is 4. And we don’t have an explanation. When the results first came through I didn’t believe it and I made the guys who ran the survival analysis run it again. We’ve rerun it like three or four times now and with the same results.
What we think is happening is the gene is for black is tied to an immune function, so somehow black wolves have a higher survivability because they have a better immune system. Now the complicating factor is all of our black wolves except two—and we’ve genotyped over a hundred—are heterozygous black, not homozygous. Homozygous black—these guys are dying young. Heterozygous black have a survival advantage. Dan Steel is heading this work up as part of his doctorate study.
Is mange still a problem in the park?
It’s declined—it peaked two years ago. It may be something that just never goes away. We’ve handled a few wolves this year that don’t have bad mange but they have annoying cases of it.
Now that the Druids (wolf pack) are gone, who do you predict will be the next “rock star” pack?
The pack that is filling behind them is Lamar Canyon, but the biggest pack in the northern range now is Blacktail with 14 members at year-end. One trend with the wolf population decline is that pack sizes have dropped across the board, except Blacktail and Mollie’s, and Mollie’s probably hasn’t dropped because they are bison killers.
Blacktail will probably be the dominate pack in terms of size, but what gets you stardom and fame is visibility and that happens in Lamar Valley and Slough Creek—and the pack in that area is Lamar Canyon. And what also gets you stardom and fame is having charismatic individuals. And Lamar Canyon does have one with their alpha female—06 is her nickname, but she’s not collared. She’s a very smart wolf, very atypical, and a big hunter. Males usually have a lot to do with the hunt—she does it all. To the wolf-watching community she is starting to be their rock star.
What are some other trends you have found in your observations this year?
I talked about the population decline, but it’s been mainly with the northern range packs. In the interior of Yellowstone, the number of packs have been largely stable. I think that’s because for the northern packs it’s primarily a wolf-elk system, while in the interior, it’s a wolf-elk-bison system. They subsidize their diet with bison, which I think is pretty important as that population has not declined as precipitously as the northern range.
Last year we spoke about 495M—the alpha male of Mollie’s pack—a pack that regularly takes down bison. Is he still the largest wolf ever recorded in Yellowstone?
495M is a pro. He’s doing great. We think he’ll turn 7/8 in April, so he’s past his prime, but he’s still hunting bison. That is what is interesting about wolves—there is no such thing as a generic wolf. They are best at killing between 2-4, but if you have to keep killing and there’s no-one to help you, you just do it. I am skiing into Pelican Valley later this month and we’ll watch him for several days.
But there is a new big guy--760M in the Delta Pack. The last time we caught 495 he had meat in his stomach and weighed 143 pounds. When we weighed 760, he had a truly empty stomach, which I know because the effects of the drug cause them to vomit sometimes, and he was puking bile. So he weighed 147 pounds with nothing in his stomach.
I’ve been studying wolves for 32 years, and 760 was a sight to behold. I’ve handled hundreds of wolves, yet I thought he was a wonder of nature. And then I just started thinking in my head as I looked at him, he lives in the most remote area of the lower 48, and this is the kind of wolf that remoteness produces.
As a scientist you take the viewpoint that you can find answers. And for the first time I thought this is a wolf that truly has secrets. This is the Lower 48, it’s not northern Canada, it’s not Alaska, and we have a modicum of wildness here. He was something—not just another wolf. And it sort of reinvigorated my fight and restored that mystique of the wilderness for me. We have to redouble our efforts to save wildness.