Saturday, December 5, 2015

Avalanche kills Yellowstone #wolf

Wolf research in Yellowstone has produced incredible photographs, including this shot of a bison shielding her late-season calf. She successfully fended off wolves from the 14-member Prospect Peak Pack. (Yellowstone National Park)

By Angus M. Thuermer Jr. | December 2, 2015

In a rarely documented occurrence, an avalanche killed a radio-collared wolf in Yellowstone National Park in 2014.

The avalanche killed a pup belonging to the 8-Mile Pack on Feb. 14 last year, according to an annual report on 2014 wolf activities. Yellowstone released the document Wednesday, reporting at least 104 wolves in 11 packs, including 9 breeding pairs a year ago.

Biologists were not immediately available to comment on how rare such an avalanche death is. Snowslides are a mountain hazard and have been known to kill elk, deer and other alpine-dwelling species.

Mortality tables in annual reports dating back to the original wolf transplant to Yellowstone in 1995 list no other avalanche as a cause of death of a wolf. Many wolves have died of unspecified natural causes, however.

The fact that the pup was collared with a locating device may have contributed to biologists understanding the circumstances of its fate. Four other radio-collared wolves from Yellowstone died in 2014.

Two of those were “harvested” or killed by hunters outside the park. Another wolf was killed by others of its species, and one pup from Mollie’s Pack died while being captured, likely for research.
Researchers captured and handled 16 Yellowstone wolves last year, including the Mollie’s pup, the 8-page report says.

In 2003 there were almost 180 wolves in the world’s first national park — a high mark. Since 2009 the population has hovered around 100.

Wolf numbers in Yellowstone National Park have hovered around 100 animals in recent years. (Yellowstone National Park)

Wolf numbers in Yellowstone National Park have hovered around 100 animals in recent years. (Yellowstone National Park)
In 2014, 40 pups survived until year’s end. In a stable population, that would mean a similar number of adults died that year. The numbers show the limits of mortality data researchers have for park wolves.

The overall population is up from 2013 and also from 2012, when there were only 83 wolves in Yellowstone. The year 2012 was the population nadir since 1999, a graph in the report shows.
Biologists used genetic sampling from scat at a den site for the first time to estimate the size of a wolf pack.