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Based on data from these sources, the most cattle lost from 1977 through 1980 was reported to the FWS in 1979 when 7 cows and 98 calves were claimed. The 105 cattle represented about 0.45 per 1,000 available. Many of the calves could not be accounted for; merely circumstantial indications, or no evidence, of wolf involvement was available. The highest sheep losses claimed since 1977 was in 1980, when the State's compensation program paid for 36 ewes and 72 lambs (Table 1). These sheep represented about 1.18 per 1,000 available.

During 1979, the FWS conducted a preliminary survey of 55 livestock producers in north-central Minnesota. Ten of 4,970 head (0.20 per 1,000) of livestock (mainly beef cattle) at these farms were thought by the farmers to have been killed by wolves that year. The percentage of livestock producers affected by wolf predation is also small. The highest number of farms reporting complaints to the FWS was in 1976 when 35 farms (3 per 1,000) complained of harassment or depredation of livestock. Moreover, losses to wolves were verified at only 19 (1 in every 640) of these farms. Even if only 90 of the 12,230 farms within wolf range have some form of livestock, the vast majority (over 99% in 1976) of livestock producers in northern Minnesota are not affected by wolves (Fig. 1).

Most wolves do not kill livestock even when that food is available. In northwestern Minnesota, wolf packs lived very near farms without killing livestock (Fritts and Mech 1981). Territories of at least five radio-instrumented packs in the Beltrami Island State Forest bordered marginal farmland where livestock (primarily cattle) were produced, yet only one instance of depredation by these packs was verified in a 5-year period. Remains of livestock were found in 29 (3%) of 960 wolf scats collected within that study area, primarily from territories of packs that bordered some farmland. Although most of these scats probably represented scavenged cattle, six contained remains of young calves that likely had been killed by wolves (Fritts and Mech 1981). Similarly, livestock remains were found in only 1 % of 1,608 scats collected in Riding Mountain National Park in Manitoba. The park is surrounded by farmland where cattle are produced; territories of several packs bordered farmland there (L. N. Carbyn, personal communication).

Many instances of wolf depredation on livestock in Minnesota seem to be related to animal husbandry practices. For example, cattle depredations are fostered by pasturing in extensive woodlots or brushy areas and allowing calving in such areas or even in remote open pastures. These practices also make it more difficult to keep track of the herd and determine the causes of mortality. In Alberta, total cattle losses over a 4-year period were higher in a predominately forested area (3.3% of herds) than where 50% or more of the trees had been cleared and herd management was more intensive (1. 3 % of herds; R. R. Bjorge, personal communication). In Minnesota, radio-collared wolves living near farms are frequently located in wooded habitat adjacent to open pasture, but very rarely in open pasture (Fritts and Mech 1981). Therefore, cattle in a wooded habitat probably have a greater chance of being encountered by wolves.

Another practice that probably encourages and perpetuates depredations is improper disposal of livestock that died from other causes. When investigating complaints of depredations, it is not uncommon for FWS personnel to find remains of dumped carcasses in or near the pasture (Fig. 6), even though State law (Livestock Sanitation Law 35.82) requires that carcasses be buried or burned: "Except as provided in subdivision lb, every person owning or having in charge any domestic animal that has died or been killed otherwise than by being slaughtered for human or animal consumption, shall as soon as reasonably possible bury the carcass thereof at least three feet deep in the ground, or cause the same to be consumed by fire . . . ;"

Fig. 6. Cattle carcasses at a disposal site on a northern Minnesota cattle ranch. This type of illegal disposal is thought to encourage wolf depredations.

Nonetheless, many farmers dispose of dead animals improperly because proper procedures are less convenient. In a preliminary survey that FWS personnel made of 111 farmers in north-central Minnesota in 1979, 63% indicated that they either leave dead animals where they die, or transport them to the edge of the pasture, into the woods, or to a regular dumpsite on the farm. Remains of butchered animals also are left at these sites (Fritts and Mech 1981). Wolves are known to scavenge from livestock carcasses in Minnesota (Fritts and Mech 1981), as they also do in Alberta (R. R. Bjorge, personal communication). FWS personnel observed that wolves frequented carcass dumps at farms in Minnesota. This free disposal service is even welcomed by many farmers. It is possible that many wolves that ultimately kill livestock receive their first taste at a carcass dump. The experience might be their first step in learning to kill live prey of the same odor, appearance, and taste. Moreover, the presence of livestock carrion on Minnesota farms may encourage wolves and coyotes to frequent pastures which in turn increases the probability of contact between predators and domestic animals. Either higher coyote density or increased activity, or both, were found close to a cattle carcass dumping area in Arizona (Danner and Smith 1980). In Alberta, overwinter coyote numbers near some farms were greatly reduced by removal of livestock carrion (Todd and Keith 1976). Availability of carrion probably has a similar effect on wolves.

Farmers sometimes permit baiting for bears in their pasture where livestock depredations have occurred. Placement of any meat or other substance that would attract wolves and encourage their return to a pasture should be avoided.