Rockies wolf population: 1,774 minimum
by Cat Urbigkit, Pinedale Online!
March 12, 2012
The U.S. Fish and Wildlife Service has released its annual report for wolf recovery in the Northern Rocky Mountain Distinct Population Segment (NRM DPS) for 2011. That report notes:
"As of December 31, 2011, the minimum estimated gray wolf population within the NRM DPS was composed of at least 1,774 wolves in 287 packs (groups of two or more wolves with territories inside the NRM DPS that persisted until December 31, 2011. At least 109 packs met the definition of a breeding pair (packs that contained at least one adult male, one adult female, and two or more pups on December 31, 2011).
"At the end of 2011, there was a minimum of 431 wolves in the Northwest Montana Recovery Area (NWMT), 499 in the Greater Yellowstone Recovery Area (GYA), and 797 in the Central Idaho Recovery Area.
"By state, within the NRM DPS, there were an estimated minimum of 653 wolves in Montana, 328 in Wyoming, and 746 in Idaho. Twenty-nine wolves (5 packs, 1 breeding pair) were estimated to be in eastern Oregon and 18 wolves (3 packs, 2 breeding pairs) were found within the NRM DPS in eastern Washington. An additional two packs (one breeding pair) were known to exist in western Washington outside the NRM DPS. Minimum recovery goals of an equitably distributed wolf population containing at least 300 wolves and 30 breeding pairs in Montana, Idaho, and Wyoming for at least 3 consecutive years have been exceeded in the NRM DPS since 2002."¯
"Wolf Depredations: In 2011, cattle depredations were similar, sheep and other livestock depredations decreased, and dog depredations slightly increased compared to 2010. Wolves in the NRM DPS subsist primarily on elk, white-tailed deer, mule deer, and moose, but livestock are also attacked. Although confirmed depredations result in a comparatively small proportion of all livestock losses in the NRM DPS, wolf damage can be significant to some livestock producers in areas where wolves are present. Total confirmed livestock depredations by wolves in 2011 were down slightly from 2010 levels and included 193 cattle, 162 sheep, 9 dogs, and 7 other livestock (5 horses and 2 domestic bison). Approximately 58 of 294 (~20%) known NRM DPS wolf packs (outside YNP) that existed at some point in 2011 were involved in at least one confirmed livestock or pet depredation. This is slightly lower than the 2010 estimate of 25%.
"Agency Control of Problem Wolves: In the NRM DPS, lethal control of problem wolves (including agency control and legal take in defense of property by private citizens) decreased by approximately 36% in 2011 (n = 166) compared to 2010 (n = 259). In the three primary NRM DPS states, Wyoming removed the largest and Idaho removed the smallest proportion of their 2011 minimum estimated wolf population through agency control. For strictly comparative purposes, we estimated the absolute minimum number of wolves alive in 2011 by combining the 2011 NRM DPS minimum population estimate of 1,774 wolves with all known wolf mortalities from all causes (n = 166 agency control; n = 322 legal harvest; n = 92 other known mortalities). This sums to an absolute minimum NRM DPS estimate of 2,354 wolves known alive at some point in 2011 (MT = 869, ID = 1,042, WY = 392, OR = 32, WA = 19). The absolute minimum estimate was only used to compare relative rates of wolf removal among states and by cause (in this section, the "legal public harvest of wolves" section, and the "human-caused wolf mortality" section). Agency control removed approximately 7% of the absolute minimum NRM DPS estimated wolf population in 2011. By state, within the NRM DPS, agency control removed approximately 7% of the absolute minimum NRM DPS estimated wolf population in Montana, 9% in Wyoming, 6% in Idaho, and 6% in Oregon. Washington had no wolves removed through agency control in 2011.
"Legal Public Harvest of Wolves: The NRM DPS gray wolf population was removed from federal protection in all states except Wyoming in May 2011 and, subsequently, legal public harvest was instituted during the fall of 2011 in Montana and Idaho. In 2011, 322 wolves were legally harvested in the NRM DPS which accounted for approximately 14% of the absolute minimum NRM DPS estimated wolf population. Legal harvest removed approximately 14% and 19% of Montana’s and Idaho’s absolute minimum estimated wolf populations in 2011, respectively. No legal public harvest occurred in Oregon, Washington, or Wyoming during 2011; however, one wolf from a Washington border pack was legally harvested in Idaho.
"Human-Caused Wolf Mortality: In 2011, excluding agency control and legal harvest, other forms of human-caused mortality accounted for 19 known wolf mortalities in Montana, 8 in Wyoming, and 18 in Idaho. Oregon and Washington had no other forms of human-caused mortality in 2011. When all forms of human-caused mortality were combined (agency control, legal harvest, and other human-caused mortality) a total of 204 wolves were removed in Montana (~23% of absolute minimum NRM DPS estimated population), 45 wolves were removed in Wyoming (~14% of absolute minimum NRM DPS estimated population), 281 wolves were removed in Idaho (~27% of absolute minimum NRM DPS estimated population), 2 wolves were removed in Oregon (~6% of absolute minimum NRM DPS estimated population), and 1 wolf was removed in Washington (~5% of absolute minimum NRM DPS estimated population). Overall, approximately 23% of the NRM DPS absolute minimum estimated wolf population was removed due to human-causes."¯
To read the complete annual report, click on the link below.