This is not a study, rather it is an interesting article that I found credible based off of the quotes by biologist Craig Gardner.  It reflects the findings of territorial aggression found in other published studies, but I wanted to include it on the site based off of the observations that wolf packs sometimes explore far off their home territory to "probe". 

Could this behavior be related to and what has been selectively bred for in certain working dogs that seem to have a stronger instinct to roam, such as we see in huskies?

Tim Mowry's article below:

Originally published Thursday, February 19, 2009 at 12:00 a.m.
Updated Thursday, February 19, 2009 at 9:34 a.m.

http://newsminer.com/news/2009/feb/19/canid-carnage/

FAIRBANKS - For all the controversy and headlines that Alaska’s aerial wolf control program generates, the real killer of wolves in the Last Frontier escapes the spotlight.

Wolves — not hunters, trappers or government-permitted sharpshooters in Super Cubs — kill most of the wolves that die in Alaska each year.

“Intra-specific strife is common,” is how Fairbanks wildlife biologist Craig Gardner puts it, after 22 years studying wolves and other critters for the Alaska Department of Fish and Game. “Wolves kill wolves.”

Gardner, who also traps, estimates that about half the wolves that die each year in Alaska are killed by other wolves.

According to estimates from the Department of Fish and Game, there are anywhere from 7,000 to 10,000 wolves roaming Alaska. In an average year, about 1,250 are killed through hunting, trapping and predator control.

Fellow biologist Tom Meier, who studies wolves in Denali National Park and Preserve, figures that “at least” 60 percent of the wolves that die in Alaska’s most famous national park are killed by their canid cousins.

“That, by far, is the most common cause of death,” he said.

The number would probably be higher than 60 percent, Meier said, but biologists have a hard time determining how some wolves die because “by the time we get to the carcass, there’s not enough left to figure out how they died,” he said.

“Some of those are probably killed by wolves, too,” Meier said.

The park service tries to keep radio collars on at least two wolves — usually the alpha male and female — in each of park’s 18 wolf packs, which enables biologists to track different packs for research. The packs in Denali Park range from three to 20 wolves, and the total population is about 100 wolves.

“We have to put out 20 (collars) a year because so many do get killed,” Meier said.

Fang wars

Wolf packs in Alaska may be a symbol of true wilderness to many people, but in some respects they resemble inner-city gangs.

Each wolf pack has a pair of leaders, the alpha male and female. Each pack has a territory, or turf, it marks and defends. Fights between packs are common — and often deadly.

In the past two years, Gardner has documented several fights between wolf packs on the Tanana Flats south of Fairbanks while tracking roughly a dozen wolf packs as part of a study examining lice on wolves in the area. Gardner didn’t actually witness the fights, only the aftermath in the form of dead, radio-collared wolves he picked up or injured wolves he spotted from the air.

“There have been some pretty good rumbles,” Gardner said.

The latest brawl occurred in October between the Clear Creek Butte and Tatlanika packs. Judging from what he can piece together from his tracking flights, the Tatlanika Pack traveled more than 40 miles out of its territory to end up where it did.

The alpha male and female in the Clear Creek Butte Pack, both of which were wearing radio collars, were killed in the fight, Gardner said. While it’s impossible to say how many wolves were killed in the fight, it appeared both packs suffered significant losses. There are six wolves unaccounted for in the Tatlanika Pack, Gardner said.

“All we know is they left with 15 wolves three or four days before the fight and they came home with nine,” Gardner said of the Tatlanika Pack.

The Clear Creek Butte pack, meanwhile, had decreased from 13 to nine wolves, he said.

“It looks like a bomb went off in both of them,” the biologist said. “I’ve never seen it where it looked like a hockey fight. It looked like they all just dropped their gloves and went at it.”

Bite to kill

More often than not, it’s the alpha males or females that are killed “because they’re the ones out front doing the fighting,” Meier said.

Danny Grangaard, a former wildlife technician for the Department of Fish and Game in Tok who is considered one of the state’s most expert wolf trappers, agreed.

“You rarely see anything but the dominant male or female dead,” he said.

Big wolf packs pick fights more than smaller packs, too, Grangaard said.

“When you get a big pack they’re a lot more aggressive than a small pack,” he said.

Big packs have more big wolves and it’s typically the big males that do much of the fighting, Grangaard said.

“If you’ve got a small pack, you won’t have two big males,” he said. “But if you get a pack of 16 or 17, there’s going to be two or three 120- or 130-pound males.”

Typically, wolves that are killed in fights are not torn to shreds.

“They’re not all ripped apart, but if you skin them there’s all kinds of hemorrhaging (from bite marks),” Meier said.

Both Meier and Grangaard have found dead wolves with teeth holes in their skulls as a result of fights. Nearly all the male wolves Grangaard has found dead from fights have holes in their skulls from canine teeth.

“It’s always just one bite in the head and a skull fracture,” he said. “There ain’t no bite marks on the necks or shoulders.

“Their intention is to kill, not get in a fight,” Grangaard said. “When they bite, it’s some place that’s going to do damage.”

Grangaard has come across the aftermath of several wolf fights over the years, both while trapping wolves and tracking them for the Department of Fish and Game. The fights don’t appear to last long, he said.

“You look at the tracks in snow and I’ll bet that fight lasts two minutes,” Grangaard said. “There’s very few tracks and a wolf laying there dead.”

Defending their turf

It’s all about territory.

Fights between wolf packs usually occur when one pack trespasses into another pack’s territory, which happens often, according to biologists who track wolves.

Most of the time, wolf packs do what they can to avoid each other, which is why they continually mark their territories, Gardner said.

But sometimes wolf packs get so big they tend to make large movements out of their territories, he said. They go on a one- or two-week foray — or “holiday,” as Gardner put it — and end up bumping into another pack. Most fights happen on the edges of territories, he said.

At the same time, Gardner has seen packs of wolves almost deliberately cross into another pack’s territory.

It doesn’t appear their movements into other territories is driven by a lack of food. Even wolves with plenty to eat in their own area will pack up every now and then and explore a neighboring pack’s territory, he said.

Independent wolf researcher Gordon Haber, who has studied wolves in Denali Park for more than 40 years, calls them “extraterritorial forays.” Haber said wolves are constantly “probing” adjacent territories and it doesn’t take them long to pick up on vacancies, which they are quick to take advantage of.

“It doesn’t take them more than a few weeks or even days for them to pick up on that,” Haber said.

Neither does it take long for wolf packs to detect intruders in their territories.

“I’ve always been impressed by how fast resident wolves can detect it and from how far away,” Haber said.

He has seen instances where a neighboring pack crosses into another pack’s territory and the resident pack picks up on it from 10 miles away, even though the wind is blowing in the wrong direction to pick up their scent.

Several years ago, Haber witnessed two wolf packs meet on the Denali Park Road in what he was sure was going to be a fight as he was tracking wolves in an airplane.

“They just milled around each other all huffed up,” he said. “It was the strangest thing. We figured we were going to see fur and blood fly everywhere.”

Hungry country

Cannibalism among wolves is not uncommon, either.

While Meier has never seen wolves kill members of their own packs, he has seen wolves cannibalize pack mates after they are killed by other wolves or die for other reasons. He recalled an incident several years ago in which 6-month-old pups ate their parents after the older wolves were killed in a fight.

It’s not unusual for trappers to find wolves they’ve caught eaten by other wolves, especially when they are caught in snares, Grangaard said. Surprisingly, that’s not the case with wolves caught in leg-hold traps, Grangaard said, perhaps because the trapped wolves are still alive when other wolves arrive on scene.

“I’ve had a lot of heads hanging in snares, where the whole body has been eaten,” he said, recalling one winter when he lost nine trapped wolves to cannibalism.

Once, Grangaard said, he interrupted a wolf eating another wolf he had snared.

“When he heard me coming he took off and hit another snare,” he said.

In recent years, Meier said, he has seen more wolves being eaten after they are killed.

“Last winter, just about every wolf we went to check out was eaten,” he said. “I don’t think they’re killing them to eat them. They’re killing them for the territory.”