Pack Size-

There has been much dispersal, some control kills and perhaps a few unidentified deaths of uncollared wolves this winter.  Below are the packs' size at the beginning of the winter, and just prior to denning this spring.

Chief Joseph. 10 to 6

Crystal Creek. 14 to 5 (this once huge pack has seen a great reduction in its numbers, and it not clear that no. 5F is still the alpha female. She, like no. 9F, is getting pretty old), although she is still with the pack. Crystal Creek's sole pup from 1999 has disappeared.  Despite the reduction in its size, this pack regularly kills bison.

Druid Peak. 9 to 8.

Gros Ventre. 5 to 5

Leopold. 13 to 6. Just one pup survives.

Nez Perce. 13 to 11. This is now the largest pack in Yellowstone, replacing Rose Creek as the biggest.  This is the only pack that consists entirely of gray wolves.

Rose Creek. 16 to 10. There are numerous dispersers.

Soda Butte. 3 to 8. This pack has been rejuvenated. The original alpha female, no. 14F is still going strong. She is often observed far in out in front leading the pack. 

Sheep Mountain. A number on control killings last fall greatly reduced this pack.  I believe the current count is 6.

Sunlight Basin. 9 to 6. 

Teton. 6 to 7 to 6. Recently the body of an emaciated wolf was found in the Gros Ventre River drainage.  Her back was broken, probably from an encounter with prey. The age of the wolf was two years or less.  I think she was one of the pups, which would explain why the pack which seemed to have acquired a new member (a possible mate for no. 24F?) during the winter increased to 7 and then went back to a count of 6 

Washakie II. Intensive research during winter showed that one wolf used the Dunoir area.  There is no Washakie II pack, and perhaps there never was.

Mate and progeny of the late 78F. Unknown.  She was the only collared member of pack. She was found dead last winter, killed illegally in the Absaroka Range of Montana, in a tributary of Mill Creek.  A maximum of 6 wolves from this pack could have survived.

Potential new packs-

Valentine. This trio of adults, including famous no. 9, is expected to have pups this month. They reside in the far SE corner of Sunlight Basin. Biologists wonder if it will no. 9 with pups, or her daughter.  Twin litters with just three adults would be very difficult to feed.

 No. 115F and uncollared wolf.  They are in the Taylor Fork of the Gallatin River NW of Yellowstone, new territory for wolves.

No. 55M and uncollared wolf. This pair is just south of Ted Turner's famous Flying D Ranch. Endangered species coordinated for the Turner Endangered Species Foundation said that wolf packs that migrated onto the ranch would be very welcome. 

Mammoth pair. A pair of wolves is living in the Mammoth vicinity. Due to the density of prey, there it likely room for one more pack here.  I wonder if the day will come when wolves chase the omni-present elk across the lawn at Mammoth?

Gravelly Range pair. Two or three wolves have been noticed during the winter in or near the Wall Creek State Wildlife Management area south of Ennis.   This would be the most westerly Yellowstone area pack. 

Hunting and prey-

Wolves on the northern range of Yellowstone continue to concentrate on elk.  Winter study in 1999 indicated 86% of the prey was elk, however the wolves are beginning to learn how to kill bison.  Contrary to common belief the average sized-wolf hunting group was 3 wolves, not the entire pack.  However, all observations of bison kills, showed the entire pack engaged.  Bison kills begin in the late winter and increase in early spring.

In the early winter wolves on the northern range killed an ungulate every 3 - 4 days. In the late winter the kill rate was one every 2 - 3 days. During the winter, 40% of elk kills were calves, 35% were cows (with an average age older than those taken in the late Montana elk hunt). 14% were bulls. The remainder were unidentified.

Chases of elk that were recorded showed a wolf success rate of 19%.  

Regrettably there is little information about the wolf predation in the summer.

Yellowstone wolf size-

The average weight for Yellowstone adult wolves is heavy -- 113 pounds.  Pups captured during winter averaged 85 pounds for females and 95 for males.

Wolves and grizzly bears-

When it comes to competition for a wolf-killed carcass and grizzly bears, it is observed that the bears win the carcass 90% of the time.  This compares to about 50% bear success in Canadian observations.