Carnivores, cortisol and crap seem a fitting starting point when seeking to quantify the financial losses to livestock producers by wolves. A Wyoming-based outdoorsman recently compared placing wolves in Colorado to placing a trout in a bathtub, an analogy I just can’t get out of my mind. The same analogy could be used in California, the site of a study that seeks to quantify the indirect losses to livestock producers due to wolf presence. It also illustrates the utter inappropriateness of California as a landscape fitting for wolves.

Dr. Tina Saitone, a University of California Davis professor and cooperative extension specialist in livestock and rangeland economics centered her research on three California wolfpacks to put a number on both direct and indirect losses after the California Department of Fish and Wildlife launched a pilot program to compensate ranchers for wolf-related losses. She said it became quickly apparent there is little research on the costs of indirect losses to livestock producers, especially in states like California and Colorado, where wolves haven’t been present for centuries.

In California, and Colorado for that matter, proponents claim losses due to wolves aren’t a widespread problem. This study begins to build evidence to illustrate the multiple aspects of the issue.

Stay up to speed: Sign up for daily opinion in your inbox Monday-Friday

Saitone said the study took a village. She pitched the study to her husband, Dr. Ken Tate, a UC Davis professor and Cooperative Extension specialist in rangeland sciences. Ben Sacks, director of the Mammalian Ecology and Conservation Unit in the UC Davis Veterinary Genetics Laboratory, joined to analyze wolf scat. Brenda McCowan, a professor of population health and reproduction at UC Davis Veterinary Medicine, examined cortisol levels.

The team found:

• One wolf can cause between $69,000 and $162,000 in direct and indirect losses from lower pregnancy rates in cows and decreased weight gain in calves;
• Total indirect losses are estimated to range from $1.4 million to $3.4 million depending on moderate or severe impacts from wolves across the three packs;
• 72% of wolf scat samples tested during the 2022 and 2023 summer seasons contained cattle DNA; and
• Hair cortisol levels were elevated in cattle that ranged in areas with wolves, indicating an increase in stress.

Saitone said she took a preponderance of evidence approach. Scat samples were gathered during the summers of 2022 and 2023. The samples were taken to the UC Davis veterinary genetics laboratory where Dr. Ben Sacks first determined the scat samples belonged to wolves as a host species. Sacks also genetically assigned the host an identity within the sample population. At that point, the prey was delineated to determine the wolf’s diet. Across the samples, Sacks determined 72% of the wolf scat samples contained cattle DNA.

This is unusual compared to places where wolves have been present for much longer periods of time. California lacks any real native ungulate population so it is cattle that are primarily contributing to the diets of wolves. This evidence will be significant as California cultivates a compensation program for livestock producers.

Before wolf proponents can claim this study doesn’t apply to Colorado given the large ungulate population, the other two portions of the study add to the preponderance puzzle.

California wildlife officials won’t share GPS data on wolves, even with UC Davis researchers, so a series of motion-activated game cameras were installed. Those cameras caught footage of wolves moving within cattle herds, stalking cattle and “dogging” them throughout the night.

The third portion of the study is the most interesting and relates to the stalking events captured on film. Cattle tail switches, which continue to grow, compared to cattle body hair which sheds seasonally are the bottom portion of a cow’s tail. By clipping a portion of the switch prior to turning the cows out to graze for the summer and then collecting that regrowth in the fall, the researchers had a picture of that cow’s stress throughout the summer based on cortisol levels.

The 2022 data is available, and that preliminary data suggests cattle grazing in the presence of wolves have 37% higher cortisol levels than cattle that grazed without wolves. There are innumerable studies pointing to the role of stress in reductions in conception rates and lower body condition scores. This study gives a picture of that stress in a measurable way. Paired with the other data from the study, it helps producers better inform discussion about the real value of indirect losses. And that, dear readers, is no crap.

Rachel Gabel writes about agriculture and rural issues. She is assistant editor of The Fence Post Magazine, the region’s preeminent agriculture publication. Gabel is a daughter of the state’s oil and gas industry and a member of one of the state’s 12,000 cattle-raising families, and she has authored children’s books used in hundreds of classrooms to teach students about agriculture.