By Cat Urbigkit, Range Writing columnist
Wolves were confirmed as killing cattle in northern Colorado around this time last year, reportedly the first wolf depredation in that state in more than 70 years. In between bouts of attacking and killing cattle, the wolves also killed one dog and injured another. The dogs were border collies used to work cattle and were killed in a ranch yard.
Wolves killing dogs isn’t a rare occurrence in areas where the canine cousins overlap; in some areas, it’s a fairly common occurrence.
For example, 18 dogs were killed by wolves in Wisconsin in 2022, and another nine dogs were injured. Although most of the dogs that were attacked were hounds involved in hunting or training for hunting, two of the dogs killed this year were pets, including an 8-year-old Pomeranian.
The Wisconsin Department of Natural Resources maintains a website and phone app where it maps “wolf caution areas” due to recent conflicts between wolves and dogs.
The agency reports, “Although wolf attacks on pet dogs in residential areas are rare, they do occur and have increased in recent years.” In 2016, more than 40 dogs were killed by wolves in that state.
What does vary is the type of dog killed by wolves, which is largely reflective of the interconnected human-dog use of areas occupied by wolves.
In Alaska, it’s tethered sled dogs.
In Wisconsin, it’s trailing hounds used for hunting.
In Wyoming, it’s livestock guardian dogs used to protect domestic sheep flocks. In 2021, a wolf pack (the Dog Creek pack located in western Wyoming) killed or injured five livestock guardian dogs, according to the Wyoming Game & Fish Department’s Annual Wolf Report.
The agency’s report only covers wolf attacks under WG&F’s jurisdiction in northwestern Wyoming, so the number reported is the minimum number of such conflicts that occur in the state any given year.
Although some wolves will kill dogs as prey, it’s more common for wolves to attack dogs as a means of territorial defense, eliminating a potential canine competitor.
A 2014 paper by researchers with the Norwegian Institute for Nature Research noted that most information on the killing of dogs by wolves comes from wildlife management agencies who keep such records because the agency provides compensation. But this data only covers the killing of dogs that have an identified owner and where dogs are kept close to the owner such that the attack can be documented.
These researchers obtained agency records from seven European countries and six U.S. states and found “the picture that emerges is of dog killing being a chronic but low intensity conflict with relatively few dogs being killed per year.” The killings were generally sorted into three categories: loose dogs used for recreational hunting; livestock guardian dogs protecting livestock; and pet or guard dogs that are killed close to houses or in recreational areas.
The researchers also looked at dog occurrence in wolf diets, and found “dog killing is widespread, but rarely intense, with dog presence typically constituting just a few percentage points in occurrence.” There were exceptions in several counties where specific wolf packs lived close to large towns and apparently treated dogs as prey.
“There has been relatively little research investment in this topic and there have been even fewer analyses that try to explain variation in dog killing in space and time,” the researchers wrote. “Wolf population size, low wild prey density, the way in which dogs are kept or used, and the existence of specialized problem packs are four factors that are often cited as being important for determining the numbers of dogs killed. However, there has never been a formal analysis of these patterns. A further uncertainty lies in the motivation for wolves to kill dogs, which seems to be both motivated by predation for food and territorial defense, but again these patterns have never been formally analyzed.”
When risk rises
A new paper published in the Nordic journal Wildlife Biology suggests that the risk of wolf attacks on dogs was highest when the density of wild prey was low. That probably seems like common sense, and it will predictably be cited by wolf advocates when wolves kill dogs in areas far away from the paper’s study area in northern Europe. But it’s important to understand the context of such findings, to learn of the differences and similarities to other areas where wolves and dogs interact, and to gain insights that won’t make headlines but offer intriguing information about wolf behavior that may apply to other areas.
First, here’s the basics of the new research paper: The researchers examined about 20 years of data on wolf attacks on dogs in Estonia and eastern Finland (the two study areas are separated by the Gulf of Finland).
- 80% of the land in the study area is covered by conifer forests,
- moose are the primary prey species for wolves,
- 276 dogs were killed by wolves, and
- wolves primarily killed dogs in hunting situations.
- Is more agricultural, with about half the area in forests,
- the primary prey for wolves are wild boar and roe deer,
- 168 dogs were killed by wolves, and
- 90% of dogs killed by wolves were in their owner’s yards.
There are major differences in the circumstances of the attacks on dogs between the two study areas. In Estonia, wolves killed dogs in their yards, but in Finland, most of the dogs were killed while hunting. The two dog breeds killed were regional breeds that are used for primarily for hunting hares and moose. When the dogs corner a moose, they bark and vocalize until the hunter arrives on the scene to dispatch the prey animal. Those vocalizations may attract wolves, which would then kill their canine competitors.
In Estonia, where most dogs were killed in their yards, the majority of wolves that killed dogs were identified as “subadult vagrants or pairs moving often near residential areas. Such wolves are seeking for or just going to establish their own breeding territory and may be motivated to remove potential competitors.” The researchers then pointed out that while it’s obvious that “wolves can catch dogs more readily than wild prey, and subadults that are still unexperienced as hunters may face difficulties more often than adult wolves. Dispersing individuals may at least consume more livestock than stable packs. “
The northern Europe paper followed up on research of its primary author in an adjacent area of Finland that was published in 2003 and found that 76% of all dogs were killed within the territory of one wolf pack – in people’s yards. “The wolves mostly (70%) attacked dogs in house yards. It appeared that wolves in the territory were actively seeking for dogs rather than killing them as a result of random encounters. A strong tendency to attack dogs seemed to be adopted by pups born to the wolf pack. We did not find evidence that the density of primary prey or resident dogs were associated with the risk of wolf attacks.”
That 2003 paper also noted: “Our results suggest that, in the wolf pack exhibiting strong aggressive and/or predatory behavior towards dogs, this behavior may constitute a tradition that may be passed on from generation to generation within a family unit. The hypothesis that aggressive behavior by wolves towards dogs is an inherited, traditional behavior, has important management implications and should be investigated further.”
Several papers have suggested that dispersing wolves, and newly established pairs of wolves, are responsible for a number of attacks on dogs, and also suggested that these dispersing wolves may consume more livestock than stable packs, as suggested in a 2016 paper on wolf diets in northern Italy. In that paper, the researchers noted that wolf packs “do not hunt only according to prey abundance, but accessibility, vulnerability and profitability of prey as well as composition of ungulate community, wolf foraging behavior, previous hunting experience, cultural transmission, and learning from parents can heavily affect food choice and predator diet.”
“We also found that the packs consume more wild ungulates than the dispersing wolves, and dispersing individuals showed a greater use of livestock than packs. Dispersing wolves are mainly young individuals and their hunting success is usually lower than that of older ones; because of this they could direct predation on livestock that, because of domestication, have less effective defenses against predators than wild large prey. Moreover, dispersing wolves can cover great distances in a short time and therefore do not have the time to learn the wild prey distribution; as a consequence dispersing individuals can attack livestock herds that have a greater detectability because of their highly clumped distribution and their small movement.”
No matter where conflicts between domestic dogs and wolves occur, wolves usually feed on the dogs they kill. Although dogs aren’t important as a prey item for wolves, it appears most attacks are aimed at removing other potential canine competitors from the landscape.
While researchers suggest that the risk of attacks on dogs in house yards can be reduced by installation of wolf-proof yard fences or by taking dogs inside at night, there are few – if any – effective ways to protect loose dogs that are engaged in hunting activities or protecting livestock when they encounter wolves. Some dog owners use Kevlar or spiked harnesses and collars, but these devices offer only limited protection.
Colorado’s recent experience with wolves is consistent with wolf behavior in other areas of the world. Colorado’s draft wolf restoration and management plan states: “As wolves expand their range in Colorado, dog owners will need to be aware of the potential risks to their animals if they are within wolf pack territories. Some wolves will occupy areas near human habitation and areas with heavy recreational use (e.g., national forests), which could put hunting or pet dogs at risk of attack, especially if they are running at large.” Although a section of Colorado’s plan written by its Technical Working Group notes that “wolf attacks on pets are uncommon,” that doesn’t really begin to describe the extent of wolf attacks on dogs, wherever the two species overlap.
Cat Urbigkit is an author and rancher who lives on the range in Sublette County, Wyoming. Her column, Range Writing, appears weekly in Cowboy State Daily.