“Grizzly bears (Ursus arctos) killed fifty-one calves and 6 adults...” (Abstract)

“Black bears (Ursus americanus), although present, were not implicated in cattle depredation.” (Abstract)

“... estimated depredation equaled 78 calves or 1.3-2.2% of annual calf herd. All observed depredation occured at night (n=9).” (Abstract)

“... 10 [radio-tagged grizzly bears] were located near cattle more frequently than expected (P < 0.05), but most did not kill cattle. although individuals from all sex and age (subadult, adult) groups except subadult males killed cattle, 3 adult males were responsible for 90% of confirmed losses. We employed management actions including euthanasia, translocation, and aversive conditioning to remove chronic depredators. No depredations were discovered following absence of the 3 depredating males in 1996, unlike the previous 2 years when losses continued for an additional 4 to 6 weeks. This suggests that removal of chronic depredators can reduce losses. Other bears did not become more depredatory, although many were known to utilize cattle carasses. Removal of cattle carcasses during 1996 appeared to reduce bear densities but did not deter depredatory bear behavior. Identification and removal of depredatory individuals appears key in addressing conflicts with grizzly bears on rangelands.” (Abstract)

“...Knight and Judd (1983) reported that bears rarely killed cattle when they coexisted around Yellowstone National Park, and Claar et al. (1986) proposed that most grizzlies were not cattle depredators.” (247)

“Our objectives were to investigate (1) the extent of cattle losses attributable to bears, (2) the number and proportions of bears using the area and killing cattle, (3) the effects of lethal and non-lethal management actions on reducing problems, and (4) the impications for recovery of the threatened Yellowstone grizzly bears populations.” (248)

“Bear depredation was evident in 39% (51 of 132) of calf and 12% (6 of 49) of adult mortality we confirmed. Calves were the most common victims of bear- (90%) and non bear-caused deaths (65%), although proportions differed...” (251)

“Our findings suggest that grizzly bears from most sex-aged cohorts will opportunistically prey on cattle.” (252)

“Our findings suggest a bear’s presence near cattle does not indicate depredatory behavior, contrary to what has been suggested historically (e.g., Murie 1948). Most bears we monitored exhibited a significant spatial association with cattle while depredations were occuring, but few preyed on cattle. Some bears were depredators, some were scavengers, and yet others coincidentally shared cattle range (e.g., during the non-depredation periods).” (252)

“Our anecdotal observations suggested that depredatory behavior by bears produced noticeable changes in cattle behavior, while non-depredatory bears traveling near cattle did not.” (253)

“Range managers on Blackrock-Spread Creek Area (BSA) contended that depredatory bears caused increased stress to livestock, which exasperated illness symptoms thereby reducing survival rates. Mortality from larkspur (Delphinium spp.) poisoning and pneumonia may increase among excited cattle, but the outcome of fatal illness, such as brisket disease, would not be affected.” (253)

“Redistribution of livestock carrion has reduced human-grizzly bear conflicts (Madel 1996) and could be useful in reducing cattle losses. Success of redistributing or removing cattle carcasses appears limited, however, because depredatory bears continued to prey on cattle despite the reduction of carrion during our study.” (253)

“Thus, while carcass removal may reduce the concentration of bears in an area, it may not prevent bears from developing depredatory tendencies or repel depredating bears from grazing areas.” (253)

“We successfully hazed 1 depredating bear from cattle durring the 1996 grazing season that, together with removal of another depredating bear, terminated bear depredation during the remainder of the grazing season. However, weak transmitter strength and low search intensity outside the study area preventd us from determining if the hazed bear moved to another cattle allotment. We attempted to hazing the same bear from BSA again during the 1997 grazing season (following this study) without success. Thus, hazing bears from cattle may only provide temporary and local relief, analogous to translocating bears. This approach, however, may be useful in sensitive situations where the target individual is considered important in maintaining population viability (e.g., adult females).” (253)

“In cases involving habitual depredators, however, the reappearance of problem individuals is expected and translocation efforts are not a long-term solution.” (253-254)

“Bears may also become increasingly difficult or virtually impossible to capture after repeated translocations (this study), increasing time and effort recapturing them.” (254)

“Unfortunately, we were unable to identify management techniques that were as effective as permanent removal in alleviating cattle losses... Our findings suggest that relatively few removals are necessary if highly selective techniques are applied.” (254)

“We did not identify the factors leading to the development of depredatory behavior, which merits further investigation.” (254)

“One drawback to permanent removal is that immigrants might move into the area and become chronic depredators, thereby creating a population sink.” (254)

“In reviewing Murie’s (1948) study on BSA 49 years earlier, we noted a few similarities. First, depredatory bears selected juvenile over adult cattle... Second, Murie’s results implied the adult male bears might have been the primary culprits, similar the our observation... Third, both studies failed to detect black bears as cattle depredators despite thier presence.” (254)

“... hazing results are dependent on a bear’s sensitivity to disturbance, and though a bear may leave a problem area, the action should not be considered successful if the bear continues depredatory behavior elsewhere. In chronic depredation situations, permanent removal of depredating bears of cattle may be the only long-term solution.” (255)