Wolf population continues increase
New report by the U.S. Fish & Wildlife Service
by Cat Urbigkit, Pinedale Online!
March 21, 2007
The wolf population in Wyoming in 2006 included at least 311 wolves and was a 23-percent increase from the year before, according to a new report issued by the U.S. Fish and Wildlife Service.
The number of wolves in Yellowstone National Park increased 15 percent (to 136 in 2006) but wolf numbers in Wyoming outside the park increased 31 percent, to 175 wolves in 2006. Yellowstone had 13 packs including 10 breeding pairs producing about 60 pups that survived through the end of the year. The average pack size in the park was 10.5, but ranged from four to 19 wolves.
The FWS annual report noted that elk numbers in Yellowstone park have declined by about 50 percent since 1995, when Canadian wolves were released in the park. With the park saturated with wolves, FWS expects wolf numbers in the park to decline over the next several years.
In Wyoming but outside the park, had a tally of 23 packs including 15 breeding pairs producing about 58 pups that survived through the end of the year. The average pack size was 6.7, but ranging from two to 13.
The wolf population in Yellowstone Park rebounded 15 percent in 2006 after a population decline in 2005; however, the overall population in the park has not increased since 2003. In contrast, FWS reported, wolf numbers in Wyoming outside the park increased on average of about 28 percent each year since 2003.
FWS reported that wolves in Wyoming were responsible for killing 169 head of livestock (including 162 confirmed and 7 probable depredations) and 1 dog. Confirmed livestock depredations included 123 cattle (110 calves; 13 cows/yearlings); 38 sheep (22 ewes; 16 lambs); and 1 horse. Forty-four wolves (approximately 17 percent of the Wyoming wolf population outside Yellowstone National Park) were killed in control actions to reduce further depredations. Twenty-three of the wolves killed in control actions were in Sublette County.
At the end of 2006, FWS estimated at least 175 wolves inhabited western Wyoming outside Yellowstone National Park. Twenty-three packs contained 154 wolves and another 21 wolves (single wolves and smaller groups of non-breeding wolves) were located throughout the western portion of the state.
Fifteen packs produced at least 58 pups that survived past December 2006, but none of those packs were in Sublette County.
In 2004, FWS reported that the wolf population outside the park increased 23 percent 2003 to 2004. In 2005, the wolf population increased 33 percent, and in 2006, that growth rate was 31 percent.
FWS documented at least 21 single wolves or small groups of non-breeding wolves throughout western Wyoming, including:
General area and number of wolves:
Pinedale/Cora: 5 wolves
Flat Creek: 4-6 wolves
Big Horn Mountains: >4 wolves
Kemmerer/Hamsfork: >2 wolves
Big Piney: 4 wolves
Minimum total: 21 wolves
FWS reported that eight of the 23 known packs, plus all four of the suspected or unconfirmed packs (44 percent of all known or suspected packs) in Wyoming, were involved in at least one livestock depredation in 2006. Three packs (South Fork, Prospect, and Green River Packs) were responsible for 68 confirmed livestock depredations (42 percent of all confirmed losses). In an attempt to prevent additional livestock depredations, the entire Green River Pack was removed, according to FWS.
After repeated depredations in summer 2006, the USFWS authorized lethal removal of the entire South Fork and Prospect Packs. Four wolves were killed in the South Fork Pack and a shoot-on-sight permit was issued to the livestock producer. Five wolves were killed in the Prospect Pack.
“Despite continued effort to eliminate both packs, the South Fork and Prospect Packs still existed in December 2006,” FWS noted. “All three packs will be removed early in the 2007 grazing season if chronic depredations occur.”