Wolves can’t add, but they can multiply

The Fence Post readers concerned about the prospect of wolves in Colorado might be interested in the following notes prompted by a Montana Fish, Wildlife and Parks press release reported in the Daily Montanan Aug. 1, 2022.

Montana’s wolf population decreased by 40 in 2021. The estimated wolf population in Montana at the end of 2021 was 1,141, down from 1,181 in 2020. However, in the last 10 years, wolf populations saw an estimated high of 1,256 in 2011, and a low of 1,113 in 2017, which FWP said indicates a population trend that is “very stable.” (Average pack size of six wolves.)

At the end of 2021, Montana had an estimated 192 wolf packs, down from an estimated 198 in 2020. And during the last 10 years, estimated pack numbers have fluctuated from a high of 205 in 2012 to a low of 186 in 2017.

In the calendar year 2021, 160 wolves were harvested during the spring, and 139 wolves were harvested during the fall. Additionally, 39 wolves were killed during that same time as a result of killing 96 livestock, including 67 cattle and 29 sheep. (Wolves in Montana take an average of 60 cattle out of 2,500,000, or 1 in 41,666 per year.)

The 2021 elk population in Montana was 141,785 — far over the state’s objective of 92,138. Colorado’s elk population in 2021 was over 280,000, nearly double that of Montana’s.

The July 22 article in The Fence Post, “Wolves or Elk, Deer and Moose,” took issue with wolf numbers: “…asking Colorado to bring 750 wolves into the state versus the 250 that the state voted for.” Those numbers are estimates of eventual populations, not numbers to be translocated. An aside: A total of 31 wolves from 10 Canadian packs released in Yellowstone in 1995-1996 grew to 174 wolves by 2003, and have leveled out at about 100.

One could ask, “If Montana’s 141,785 elk can support 1,141 wolves, couldn’t Colorado’s more than 280,000 elk sustain twice that?” Recall that Montana has seen a high of 205 packs and 1,256 wolves.

The Colorado Wolf Restoration Plan recently drafted by several conservation groups suggests that, “The first phase of wolf reintroduction in Colorado should entail releasing one breeding pair in each of 12 pack zones, with the goal of establishing 13 successful breeding pairs persisting for 2 years — one pair in each of the 12 pack zones, plus the existing North Park pack.” By my tally, 12 breeding pairs would total 24 wolves, not 750.

The conservation groups’s plan discusses a population goal as follows:

“Three separate studies by scientists have shown that the region could again support over 1,000 wolves (Bennett, 1994; Carroll et al., 2003, 2006). There is suitable habitat for at least 150 packs, or approximately 750 wolves (with a range of 600-1,500), and that should stand as the minimum presence of wolves in Colorado to be achieved over time. This figure is supported by the geographic features of Colorado, the ample prey base for wolves found in the state, the importance of successful breeding pairs for building a sustainable population and basic conservation principles to ensure that Colorado’s wolf population can indeed be “self-sustaining” over time, as mandated by state law.”

Those numbers appear quite conservative, in view of Montana’s numbers. Conservative, too, considering that North America hosted about 380,000 wolves, based on a genetic analysis by Leonard et al in Molecular Ecology (2005).

It is worth observing here that as of 2017, Colorado tallied 24,933 loose dogs. Even 1,000 wolves would be 1/25 of that number. USDA’s Animal and Plant Health Inspection Service reported in 2017 that dogs took twice as many cattle as wolves did, and dogs took 29 times the number of sheep that wolves did. Coexistence strategies can greatly reduce those losses.

Bishop, who is from Bozeman, Mont., has studied wolves and wolf recovery both professionally and personally since 1985.


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