USGS Home
Contact USGS
Search USGS

Wolves occasionally may consume or carry away the entire carcass of a young calf, and therefore leave no evidence of predation; however, a variety of other mortality factors may also be involved. In northwestern Albert, where wolves are present, cattle losses over a 4-year period ranged from 1.3% of herds in one area to 3.3% of herds in another. Many of the losses were not found, so cause of death could not be determined. Predators caused only 19 (about 16%) of 121 cattle deaths whose cause could be determined, wolves being involved in 15 instances and bears in 4; pneumonia and poisonous plants contributed 56% of the known mortality (R. R. Bjorge, personal communication).

In some instances, carcasses are found too long after death and are too decomposed to allow determination of cause of death; decomposition of cattle and sheep carcasses is especially rapid in mid-summer. At other times the animal is found soon after death, and obviously has been fed upon, but there is no indication of which carnivore was involved. Even if there are tracks and droppings of wolves nearby, the animal could have died of pneumonia, for example, and then been scavenged by wolves.

In addition to wolves, domestic dogs, bears, and bobcats also can kill young calves and especially sheep. Coyotes are notorious sheep predators and they also kill calves in Minnesota, as FWS personnel documented in 1979 and 1980. Coyotes probably are more important predators of domestic animals in northern Minnesota than are wolves. From July 1969 through August 1974, the ratio of coyotes to wolves captured on the State of Minnesota's Directed Predator Control Program was 17:1. Coyotes are usually far more abundant than wolves in most areas of northern Minnesota where sheep, cattle, and turkeys are produced (Berg and Chesness 1978). When investigating complaints of wolf depredations, FWS personnel commonly find evidence of coyotes also being at the farm. From 1975 through 1980, at least 10 % of the complaints of wolf depredations received by the FWS were determined to have resulted from coyotes. It is the judgment of FWS personnel that compensation has been mistakenly paid for losses to coyotes on at least one farm, and possibly on others, since 1977.

The similarity between coyotes and wolves probably has led to a distorted view of the importance of wolves as livestock predators. Many northern Minnesota residents use the term "wolf" in referring to both wolves and coyotes. Coyotes are often called "brush wolves" but the "brush" may be dropped, and both species referred to merely as "wolves." When wolves were given legal protection in 1974, many Minnesotans assumed coyotes were protected.

There also is a prejudice among certain farmers toward wolves as the cause of their livestock losses. Wolves are usually blamed if their tracks have been seen in or near the pasture, if howling has been heard, or if neighbors have claimed wolf depredations in the recent past. Another possible reason for implicating wolves is that compensation can be obtained for livestock killed by them, whereas none is available for losses by other predators (including coyotes) or from other causes (St. Paul Dispatch, St. Paul, Minn., 18 June 1980). In Italy, where farmers are compensated for sheep killed by wolves, wolves are estimated to account for only 20-50% of the alleged wolf damage reported by farmers (Zimen and Boitani 1979). The existence of a compensation program in Minnesota probably results in biased damage claims there too.

Human involvement in the disappearance of livestock is rarely suspected by farmers living in wolf range. However, some poaching and rustling of livestock occurs in northern Minnesota (Grand Rapids Herald Review, 20 December 1979).