Last year the Yellowstone wolf population suffered a big decline due to very high pup mortality in addition to the normal annual attrition of yearling and adult wolves.
Last year they counted 118 wolves in 12 groups in Yellowstone at mid-year.
At year’s end, it was 116 ±2 in 11-13 packs. This was later revised 118 wolves in 16 packs in Yellowstone. Only 19 pups had survived to Dec. 31, 2005.
Back at the end of 2004, it was 171 wolves in 16 groups in Yellowstone.
This year the mid-year Yellowstone count is 143 wolves in 14 groups. This includes 76 pups!
The Yellowstone wolf population is still below that of 2004 and even 2003 (157 wolves at year’s end).
I think these data show how fast a wolf population can grow or sink, with the major factor being pup survival rate more than control killing or death of adult wolves.