wolftop2.gif (11784 bytes)

Year ends with huge decrease in Yellowstone wolf population

The long standing Nez Perce Pack has been wiped out

12-22-2005, updated 1-8-2006

In 2004 the Yellowstone Park wolf population stopped growing. This had been predicted by biologists, although anti-wolf activists and many politicians had at least pretended it would grow forever.

No one expected what happened this year, but something (probably parvovirus) killed the large majority of pups born. Only 19 pups have survived into December compared to the usual 50 or 60. As a result the Park wolf population has dropped from 171 wolves in 16 packs to an unofficial 116 ±2 in 11-13 packs (depending whether Cougar Creek is truly split, and Swan Lake regrouped). Note the official year end count was 118 wolves (added 1-17)

End of the Nez Perce Pack-As the year ends there has been one more casualty. The oldest wolf in the Park, 48F, founder and alpha female of the Nez Perce Pack was killed last week just behind Old Faithful by the new power on the Madison and Firehole Rivers, the Gibbon Pack. After her death, the remaining two members of the pack were located on the Snake River moving south out of Yellowstone Park.48F was born in 1996, north of the Park, to wolf 27F from British Columbia. Billed as the Nez Perce Pack, the members of this Canadian Pack split when they were released from the Nez Perce Creek wolf enclosure pen, with the alpha female 27F going it alone and giving birth to 5 pups north of the Park. She, and three of her pups were later captured. Pups 48F and 47M * were penned (several times in fact) with other members of the Nez Perce Pack that had been recaptured. They were enclosed with 10 wolf pups from the Sawtooth [Reef] Pack from NW Montana. The pups' pack had been slated for destruction because they killed some Montana cows, but because the wolf reintroduction program from Canada has been shut down by people like Senator Conrad Burns, the ten pups taken as added insurance the reintroduction would not fail due to lack of initial numbers.

The individual members of the Nez Perce Pack were successful, with one (30F) starting the Thorofare Pack (later destroyed by the Soda Butte Pack). 26F started the Washakie Pack, a successful pack that still exists today. Yet another pack member from B.C., the famous wolf no pen could hold (29F), started the Gros Ventre Pack near Jackson Hole. He repeatedly escaped and once dug under the pen from the outside, freeing all the wolves.

48F herself escaped only to be eventually drawn back to the pack and assume leadership when it was finally released. One of the Sawtooth wolves became her mate.This old alpha male was killed this year too. At one time the Nez Perce Pack became the largest in the Park with 24 members, but wolf competition on and near the central Plateau increased, with Biscuit Basin, Hayden Valley, Nez Perce, and Mollies all contending. Last winter Biscuit Basin migrated to Idaho and now Nez Perce is gone.

The other packs' status at the end of the year-

The end of the year finds the Druid Pack with just 4 members -- 480M, 302M, and two yearling females. No pups survived.

The Slough Creek Pack dominated the Lamar Valley and Slough Creek. It ends with 15 members, including just 3 pups (recall that the pack had 4 litters of pups!).

The Agate Creek Pack numbers 8 wolves, and has 3 surviving pups for the best pup survival ratio on the northern range.

The Leopold Pack, which had become the Park's largest, split in to the Leopold and the new Hellroaring Pack. Hellroaring Pack is 7 adults (and ? subadults) and no pups. The Hellroaring Pack occupies the range of the former Geode Pack, which the Leopolds destroyed last year. The main pack still uses the pack's traditional range on the Blacktail Deer Plateau and has 14 members, including the two surviving pups (21 pups were born!).

The Swan Lake Pack dispersed and suffered mortality from angry elk, but every so often, as Kathie Lynch first reported, 3 of the former members, all males, sometimes get together. It is not determined whether this sometime group will be called a pack for 2005. It's pretty marginal.

The Gibbon Pack, now the powerful pack on the west side of the Park, has 9 members. The number of pups is unclear.

The Cougar Creek Pack split into what is for now being called Cougar Creek I and Cougar Creek II. The Cougar Creek I Pack retains the traditional territory in Cougar Creek, Duck Creek in the Park NE of West Yellowstone. The Cougar Creek II Pack seems to have adopted the territory of the former Chief Joseph Pack which seems to have finally bit the dust after migrating north of the Park. Their old territory now claimed by this probably new pack of nine, is in the extreme northwest corner of the Park -- Daly Creek, Tepee Creek, and adjacent areas nearby.

Over on the east side of the Park's Central Plateau, the Hayden Valley Pack has 5 or 6 members with that distinctive white alpha female and no radio collars. Probably three are pups (of course, now almost fully grown).

Mollies Pack was pupless from the start this year, but they have 7 members.

The biggest pack, down in the territory where disease apparently did not strike, is the remote Yellowstone Delta Pack with 17 members, just counted. The number of surviving pups is not known, but estimated to be 5 or 6. There seems to be just one radio collar. This pack has always made short work of most collars applied.

Rounding out the Park's wolves is the Bechler Pack in the SW corner, now at its largest ever with 9 members, including 4 pups.

The Winter Study-
The first phase of the winter study is over, and the results quite interesting. The Slough Creek Pack again this year took mostly bull elk. Dr. Doug Smith told me that the poor condition of many of the bulls was interesting and hard to square with the notion that the northern range elk population is down due to predators, because in such a situation we would expect the survivors to be strong and well nourished. The depleted condition of the bone marrow suggests poor feeding opportunity. The Hellroaring Pack was very interesting. They only kiled 6 elk during study period (although perhaps a couple more were not observed due to them moving far down into and beyond the Black Canyon of the Yellowstone, just upstream from Gardiner. This pack dined on gut piles left by hunters just outside the Park. I think this is the first instance where heavy use of the remains of the hunt has been documented among Yellowstone Park wolves.The Leopolds took a mixture of calves, cows and bulls.

Next Year-

We know that wolf populations can grow rapidly. Now we know they can decline rapidly too under natural conditions. We knew that shooting wolves could reduce the population fast.

Smith said parvovirus outbreaks (this is still not yet the confirmed cause, however) usually don't happen back to back, so next year we ought to expect better pup survival, although I doubt the population will grow back to 177 in 2006. It may never reach that again.

1-8-2005. The traditional media has finally picked up on this story, especially the parvo-virus angle. Here are a few quick links to studies on parvo and other emerging diseases in wild animals.


*Wolf 47M was hit and killed by an auto soon after being released. 46M was injured by the trap, had a leg amputated, and was sent to facility in Minnesota. Wolves 49? and 50? had unknown fates. They were never captured.

Copyright © 2005 Ralph Maughan

Not to be reprinted, archived, redistributed, etc., without permission.
Ralph Maughan PO Box 8264, Pocatello, ID 83209
Wolf Recovery Foundation, PO Box 444, Pocatello, ID  83204