Wolf Predation May Not Be as Much a Factor as Once Believed

[hank scorpio]

Study of falling elk population looks at food

Although wolves have undoubtedly played a role in the elk population decline inthe Yellowstone area, other factors have also led to the big ungulate’s downturn. “It’s a bit of a complicated story,” said professor Scott Creel of Montana State University.

Too many missed meals may be the larger cause of the decline of elk in the Greater Yellowstone Ecosystem - not wolf predation or the elk's fear of being eaten by wolves, according to a newly published study.

"What seems to be happening is all these subtle behavioral responses seem to be adding up over winter," said Scott Creel, an ecology professor at Montana State University and the lead author of a study that appears this week in the Proceedings of the National Academy of Sciences. "I was initially a little surprised. When I began looking at elk-wolf interactions, I thought predation would be the main cause."

The study builds on similar theories Creel and his associates have written about over the course of the seven-year study.

Blame to go around

Over the years, various explanations have been given for the elk population decline in the Greater Yellowstone area - extended drought that diminished forage, predation by wolves, too high a hunter harvest late in the winter and predation on elk calves by bears.

Wolf predation seemed the most likely cause, since the Northern Yellowstone elk herd stood at 17,000 to 19,000 before the wolves' reintroduction to Yellowstone National Park in 1995. This year, 7,109 elk were counted, an increase from the previous two years when 6,279 and 6,738 elk were counted.

The cow-to-calf ratio in the Northern Range this year was 22 calves per 100 cows, double what it was the year before. Wildlife managers would like to see 20 to 30 calves per 100 cows.

Scat evidence

Although some calves are being lost to predators, relatively few were being killed by wolves in their first six months of life, according to Creel's radio-collar studies.

That pointed to a low birthrate as the cause.

One theory to explain the reduced number of calves was that stress from fear of predation was causing the cow elk's cortisol levels to increase to the point that they produced less progesterone, a hormone critical to carrying a pregnancy to term.

But high cortisol levels weren't detected in the 1,200 fecal and urine samples taken from elk in the Paradise Valley, Wall Creek Wildlife Management Area and the Gallatin Range over four winters. Elk in the Elkhorn Mountains, where wolves aren't present, were included in the study for comparison.

The elk living with wolves did, however, have lower progesterone levels compared with those not living with elk.

Low-fat pregnancies

What the researchers found was that whereas the elk used to migrate down to large meadows to forage on grasses the entire winter, the presence of wolves had pushed the elk into the mountains. That means that rather than grazing, as they'd prefer, the elk are turning to browse for food - shoots, leaves and twigs on bushes and trees. Although nutritious and high in protein, the browse isn't enough to pack on pounds to keep impregnated elk healthy.

Elk without the pressure of wolves ate 27 percent more food, the study found.

"Elk prefer to graze if given the choice," Creel said. "But the elk in our study area weren't hanging out in the grassy patches when the wolves were around."

Creel's study ruled out drought as the cause, since the study took place during some mild winters that should have helped elk survive and improved their body condition in winter. And elk across the rest of the state are at historic high numbers.

Comparing Africa

Upon reflection, Creel said that the Yellowstone elk herd will never likely rebound to its historic highs as long as wolves are present in the ecosystem.

"My intuition is that we have now seen a jump from one equilibrium to another," he said. "It looks to have stabilized at about 6,000 to 7,000 elk.

"But you could certainly make an argument that this is cyclic, and this is the first trough in the cycle," he added. "Perhaps the elk numbers will go back up, and then we'll bounce back and forth."

Creel noted that elk and wolves in the Greater Yellowstone Ecosystem are "tightly coupled. ... It's a pretty hard thing to know whether they'll cycle or settle into a new equilibrium."

Creel will now move on to studies of predators and prey in East Africa to see if the relationship to reproduction occurs in other species, or if it is specific to elk and wolves.

John Winnie Jr. and David Christianson, Creel's former doctoral students, co-authored the study. Their work was funded by the National Science Foundation.

http://billingsgazette.com/news/state-a ... 03286.html

[hank scorpio]

In unrelated news:

Camper fends off mountain lion with chain saw

Dustin Britton, a 32-year-old mechanic and ex-Marine from Windsor, Colo., said he was alone cutting firewood about 100 feet from his campsite in the Shoshone National Forest when he saw the lion staring at him from some bushes.

Britton revved his 18-inch chain saw and tried to back away. But the 100-pound lion followed.

As the animal pounced, the 6-foot-tall, 170-pound Britton raised his saw and met it head-on - a collision he said felt like a grown man running right into him.

"It batted me three or four times with its front paws, and as quick as I hit it with that saw, it just turned away," he said in a telephone interview with The Associated Press.

Britton later discovered he'd inflicted a 6- to 8-inch gash on the lion's shoulder. He said he was surprised the damage wasn't worse.

"You would think if you hit an animal with a chain saw, it would dig right in. I might as well have hit it with a hockey stick," he said.

The wounded animal retreated, leaving Britton with a only small puncture wound on his forearm.

The attack occurred Sunday evening at a campsite 27 miles west of Cody. Wildlife agents shot and killed the lion Monday after it attacked a dog brought in to track the animal.

Authorities say the lion was in poor physical condition and appeared to be starving. The lion was 4 to 5 years old.

Mountain lions are considered reclusive by nature and officials said the circumstances of the attack were highly unusual. Wyoming officials have documented only eight cases of mountain lions acting aggressively toward humans over the last decade.

After Britton's confrontation, he and his wife, Kirsta, decided to stay the night in their pop-up camper with their two children rather than risk packing up with the lion still on the loose.

The next morning he told a passing U.S. Forest Service employee about the incident, and that's when wildlife agents were called.

Tests for rabies and other diseases came up negative, but officials said they were continuing to analyze the animal for other potential diseases.

"It's very, very rare" for lions to attack, said Wyoming Game and Fish spokesman Warren Mischke. "We're still trying to investigate why this lion would behave this way."

http://billingsgazette.com/news/state-a ... 03286.html

Picture of the victorious Britton and wife at presstime

[Appaholic]

So, the wolves are actually helping to keep the elk from dying of starvation? So, Mother Nature is actually keeping things in balance? Go figure....

[AZGrizFan]

So, the wolves are actually helping to keep the elk from dying of starvation? So, Mother Nature is actually keeping things in balance? Go figure....

What the researchers found was that whereas the elk used to migrate down to large meadows to forage on grasses the entire winter, the presence of wolves had pushed the elk into the mountains. That means that rather than grazing, as they'd prefer, the elk are turning to browse for food - shoots, leaves and twigs on bushes and trees. Although nutritious and high in protein, the browse isn't enough to pack on pounds to keep impregnated elk healthy.

Elk without the pressure of wolves ate 27 percent more food, the study found.

This author is either a moron (most likely scenario) or has Tourettes. How can you make a statement like the headline makes (realizing he does NOT write the headline) and then have a paragraph like THIS in the story. Predation very MUCH has had an impact on the elk population. He says so himself in the damned article!

[clenz]

So, the wolves are actually helping to keep the elk from dying of starvation? So, Mother Nature is actually keeping things in balance? Go figure....

What the researchers found was that whereas the elk used to migrate down to large meadows to forage on grasses the entire winter, the presence of wolves had pushed the elk into the mountains. That means that rather than grazing, as they'd prefer, the elk are turning to browse for food - shoots, leaves and twigs on bushes and trees. Although nutritious and high in protein, the browse isn't enough to pack on pounds to keep impregnated elk healthy.

Elk without the pressure of wolves ate 27 percent more food, the study found.

This author is either a moron (most likely scenario) or has Tourettes. How can you make a statement like the headline makes (realizing he does NOT write the headline) and then have a paragraph like THIS in the story. Predation very MUCH has had an impact on the elk population. He says so himself in the damned article!

I noticed that too...

[AZGrizFan]

In unrelated news:

Camper fends off mountain lion with chain saw


Authorities say the lion was in poor physical condition and appeared to be starving. The lion was 4 to 5 years old.

Mountain lions are considered reclusive by nature and officials said the circumstances of the attack were highly unusual. Wyoming officials have documented only eight cases of mountain lions acting aggressively toward humans over the last decade.

Tests for rabies and other diseases came up negative, but officials said they were continuing to analyze the animal for other potential diseases.

"It's very, very rare" for lions to attack, said Wyoming Game and Fish spokesman Warren Mischke. "We're still trying to investigate why this lion would behave this way."

Sounds to me like something ELSE may be taking over the mountain lion's food source.

[clenz]

In unrelated news:

Sounds to me like something ELSE may be taking over the mountain lion's food source.

Maybe a wolf?



I get the "restoring nature" shit, however, nature evolved (there is something most environuts know about...right?) since the wolf was taken out of the loop. Nature is now not used to having the wolf, and it will throw the cycle off for DECADES, if not more, to come.

[Appaholic]

So, the wolves are actually helping to keep the elk from dying of starvation? So, Mother Nature is actually keeping things in balance? Go figure....

What the researchers found was that whereas the elk used to migrate down to large meadows to forage on grasses the entire winter, the presence of wolves had pushed the elk into the mountains. That means that rather than grazing, as they'd prefer, the elk are turning to browse for food - shoots, leaves and twigs on bushes and trees. Although nutritious and high in protein, the browse isn't enough to pack on pounds to keep impregnated elk healthy.

Elk without the pressure of wolves ate 27 percent more food, the study found.

This author is either a moron (most likely scenario) or has Tourettes. How can you make a statement like the headline makes (realizing he does NOT write the headline) and then have a paragraph like THIS in the story. Predation very MUCH has had an impact on the elk population. He says so himself in the damned article!

But think of the shoots, leaves & twigs being saved by the wolf.....

[AZGrizFan]

This author is either a moron (most likely scenario) or has Tourettes. How can you make a statement like the headline makes (realizing he does NOT write the headline) and then have a paragraph like THIS in the story. Predation very MUCH has had an impact on the elk population. He says so himself in the damned article!

But think of the shoots, leaves & twigs being saved by the wolf.....

Apparently you have Tourettes too. The elk are eating MORE shots, leaves and twigs BECAUSE of the wolf. I feel very sorry for the poor shoots, leaves and twigs in this world.

[Appaholic]

But think of the shoots, leaves & twigs being saved by the wolf.....

Apparently you have Tourettes too. The elk are eating MORE shots, leaves and twigs BECAUSE of the wolf. I feel very sorry for the poor shoots, leaves and twigs in this world.

All we need is a Federal Shoots, Leaves & Twigs Re-Introduction plan in Montana if that's OK with the whiny sod-busters......

[Cleets Part 2]

So, the wolves are actually helping to keep the elk from dying of starvation? So, Mother Nature is actually keeping things in balance? Go figure....

That's a crazy idea... it's just crazy enough to actually work

[AZGrizFan]

So, the wolves are actually helping to keep the elk from dying of starvation? So, Mother Nature is actually keeping things in balance? Go figure....

That's a crazy idea... it's just crazy enough to actually work

Read the article and actually contribute to the discussion for a change, Mortimer.

[andy7171]

Too bad Grizza went D1B on us and quit. I find his pure hatred of wolves quite entertaining.

[Grizalltheway]

Too bad Grizza went D1B on us and quit. I find his pure hatred of wolves quite entertaining.

As do I. The topic came up when we were having a beer last week, and the funny thing is, he doesn't get nearly as fired up about it in person, as far as I can tell.