Study Shows Single Wolf Death Can Impact Entire Pack

Jul 9, 2014

Fairbanks, AK - A new study indicates that the death of a wolf has implications for the rest of the pack, depending on the size of the pack and the dead wolf's sex. The study is in response to the legal trapping of a breeding female that was part of a well known wolf pack that was frequently spotted in the Denali National Park.

In 2012 a local trapper took a breeding female from the Grant Creek wolf pack that was known to den near the Denali Park Road. A second female died and no wolf pups survived that year. A new study suggest the death of those breeding females resulted in the pack's dispersal. 

"We found that in most cases where a pack ended, there was the loss of a breeder beforehand," said Bridget Borg, a wildlife biologist with the National Park Service at Denali National Park and Preserve.

"So, we saw that when packs are small, or when females are lost or if it's a death that occurred during the breeding season, the packs are more likely to end," she said.

Credit Alaska Department of Fish and Game

Borg and colleagues used data from a long term study of wolves in Denali National Park to identify breeding wolves and find out what happened to packs when breeders died. 

"Our research increases our understanding of the conditions under which the death of a breeder will have more of an impact on pack fate," Borg said. 

The study indicates that the dissolution of a single wolf pack may not have adverse effects on the overall wolf population. Scientists believe wolves may compensate in some cases for the death of a breeder by increasing reproductions the following year of by replacing a lost breeding wolf if the pack is large enough.

 A survey of wolves in Denali this spring tuned out the fourth lowest total count of wolves since biologists started keeping track nearly 30 years ago.

This year's spring count also shows low population density and smaller average pack sizes. Park Superintendent Don Striker says, in a press release, that the numbers raise concerns about the harvest of wolves from packs that reside primarily within the park. Striker points to implications for visitors who come to Denali to view a wolf in the wild.

The study appears online in the Journal of Animal Ecology.