Geology topics
Publications and source records attributed to L.D. Mech.
Based on 151 neonate elk calves radio-tagged in YNP, bears accounted for 55-60% of deaths, coyotes, 10-15%, and wolves 10-15%. More than 70% of this predation occurred within the calves' first 15 days.
Wolf (Canis lupus) populations tend to be resilient and to persist for long periods, and several characteristics contribute to their resilience and persistence: (1) age of first reproduction (2-3 years), (2) high annual litter size (mean = 6), (3) low dispersal age (1-3 years), and (4) long potential dispersal distance (< 880 km). The only documented factor leading to extinction of well established wolf populations with sufficient food is deliberate poisoning, although conceivably disease could have such an effect.
Incidents are described of Bison ( Bison bison ) in Yellowstone National Park mauling and possibly killing a young Elk ( Cervus elaphus ) calf, chasing wolves ( Canis lupus ) off Elk they had just killed or were killing, and keeping the wolves away for extended periods. During one of the latter cases, the Bison knocked a wolf-wounded Elk down. Bison were also seen approaching wolves that were resting and sleeping, rousting them, following them to new resting places and repeating this behavior. These behaviors might represent some type of generalized hyper-defensiveness that functions as an anti-predator strategy.
This report documents a year-around Wolf ( Canis lupus ) density of 18.2/100 km 2 and a summer density of 30.8/100 km 2 , in a northeastern Minnesota Wolf pack. The previous record was a summer density of 14.1/100 km 2 , for a Wolf pack on Vancouver Island, British Columbia, Canada.
The gray wolf once inhabited a wide variety of habitats throughout most of the northern hemisphere north of 20°N latitude. Because the animal preyed on livestock and competed with humans for wild prey, it was extirpated from much of its range outside of wilderness areas. Environmental awareness in the late 1960s brought for the wolf legal protection, increased research, and favorable media coverage. The species has increased in both Europe and North America, is beginning to reoccupy semiwilderness and agricultural land, and is causing increased damage to livestock. Because of the wolf's high reproductive rate and long dispersal tendencies, the animal can recolonize many more areas. In most such areas control will be necessary, but the same public sentiments that promoted wolf recovery reject control. If wolf advocates could accept control by the public rather than by the government, wolves could live in far more places. Insistence on government control discourages some officials and government agencies from promoting recovery. The use of large- or small-scale zoning for wolf management may help resolve the issue. Public education is probably the most effective way to minimize the problem and maximize wolf recovery, but the effort must begin immediately.
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We used data on the polymorphic status of α 1 -antitrypsin (α 1 AT) to study the relationship of Minnesota wolves to the gray wolf ( Canis lupus ), which was thought to have evolved in Eurasia, and to red wolves ( Canis rufus ) and coyotes ( Canis latrans ), which putatively evolved in North America. Recent evidence had indicated that Minnesota wolves might be more closely related to red wolves and coyotes. Samples from wild-caught Minnesota wolves and from captive wolves, at least some of which originated in Alaska and western Canada, were similarly polymorphic for α 1 AT, whereas coyote and red wolf samples were all monomorphic. Our findings, in conjunction with earlier results, are consistent with the Minnesota wolf being a gray wolf of Eurasian origin or possibly a hybrid between the gray wolf of Eurasian origin and the proposed North American wolf.
Based on 418 radio-locations of a Minnesota wolf pack, wolves were found at significantly fewer locations per area in the outer 2 km of the territory than in the core. This finding supports an hypothesis that buffer zones exist between pack territories and may explain why prey survive longer there.
Based on 418 radio-locations of a Minnesota Wolf pack, Wolves were found at significantly fewer locations per area in the outer 2 km of the territory than in the core. This finding supports an hypothesis that buffer zones exist between pack territories and may explain why prey survive longer there.
A significant relationship was found between Wolf (Canis lupus) breeding dates and latitudes between 12?? and 80??N, with Wolves breeding earlier at lower latitudes, probably because of differences in seasonality.
Seven adult female White-tailed Deer (Odocoileus virginianus) in northeastern Minnesota lived within 1.8 km of Wolf pack (Canis lupus) homesites without vacating their home ranges. Six of these deer and at least three of their fawns survived through the Wolf homesite period.
We evaluated the accuracy and precision of tooth wear for aging gray wolves ( Canis lupus ) from Alaska, Minnesota, and Ontario based on 47 known-age or known-minimum-age skulls. Estimates of age using tooth wear and a commercial cementum annuli-aging service were useful for wolves up to 14 years old. The precision of estimates from cementum annuli was greater than estimates from tooth wear, but tooth wear estimates are more applicable in the field. We tended to overestimate age by 1-2 years and occasionally by 3 or 4 years. The commercial service aged young wolves with cementum annuli to within ± 1 year of actual age, but under estimated ages of wolves ≥ 9 years old by 1-3 years. No differences were detected in tooth wear patterns for wild wolves from Alaska, Minnesota, and Ontario, nor between captive and wild wolves. Tooth wear was not appropriate for aging wolves with an underbite that prevented normal wear or severely broken and missing teeth.
Wolf (Canis lupus) depredations on livestock cause considerable conflict and expense in Minnesota. Furthermore, claims are made that such depredations are fostered by the type of animal husbandry practiced. Thus, we tried to detect factors that might predispose farms in Minnesota to wolf depredations. We compared results of interviews with 41 cattle farmers experiencing chronic cattle losses to wolves (chronic farms) with results from 41 nearby matched farms with no wolf losses to determine farm characteristics or husbandry practices that differed and that therefore might have affected wolf depredations. We also used a Geographic Information System (GIS) to detect any habitat differences between the 2 types of farms. We found no differences between chronic and matched farms in the 11 farm characteristics and management practices that we surveyed, except that farms with chronic losses were larger, had more cattle, and had herds farther from human dwellings. Habitat types were the same around farms with and without losses. The role of proper carcass disposal as a possible factor predisposing farms to wolf depredations remains unclear
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We evaluated tooth wear, cranial suture fusion, closure of the canine pulp cavity, and cementum annuli as methods of age determination for known- and unknown-age gray wolves (Canis lupus) from Alaska, Minnesota, Ontario, and Isle Royale, Michigan. We developed age classes for cranial suture closure and tooth wear. We used measurement data obtained from known-age captive and wild wolves to generate a regression equation to predict age based on the degree of closure of the canine pulp cavity. Cementum annuli were studied in known- and unknown-age animals, and calcified, unstained thin sections were found to provide clear annulus patterns under polarized transmitted light. Annuli counts varied among observers, partly because of variation in the pattern of annuli in different regions of the cementum. This variation emphasizes the need for standardized models of cementum analysis. Cranial suture fusion is of limited utility in age determination, while tooth wear can be used to estimate age of adult wolves within 4 years. Wolves <7 years old could be aged to within 1-3 years with the regression equation for closure of the canine pulp cavity. Although inaccuracy remains a problem, cementum-annulus counts were the most promising means of estimating age for gray wolves.
We examined the effects of fasting and refeeding on body composition in 9 captive adult gray wolves, Canis lupus (6 males, 3 females), during May-June 1995. Body composition was estimated by the technique of tritiated water dilution. Wolves were immobilized and weighed, baseline blood samples were taken, tritiated water was injected, and additional blood samples were taken before fasting, after 10 d of fasting, and again after 2 d of refeeding. Male wolves lost 8% (P = 0.0001) and females lost 7% body mass (P = 0.01) during the 10 d. Males lost 54% of this mass in water, 28% in fat, and 18% in protein/ash; females lost 58% in water, 20% in fat, and 22% in protein/ash. Upon refeeding, male wolves consumed an average of 6.8 kg (15.3% body mass) of deer meat per day and females consumed 6.4 kg (18.7% body mass). All wolves regained their initial mass. Males regained 24% of this mass in water, 70% in fat, and 6% in protein/ash; females regained 35% in water, 51% in fat, and 14% in protein/ash. This study provided evidence that after prolonged fasting, captive wolves could quickly and efficiently regain lost body mass after refeeding.