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L.D. Mech

Publications and source records attributed to L.D. Mech.

At least 91 records · Page 5Linked to original sources
USGS1992

Wolf specialist group

Explore the source record for details and available documents.

Species Newsletter of the Species Survival Committ↗
USGS1992

Trends and management of wolf-livestock conflicts in Minnesota

The nature and extent of wolf-livestock conflicts in Minnesota during 1975-86 was studied as part of a wolf depredation control program. The level of wolf (Canis lupus) depredation on livestock in Minnesota, as determined from the total number of complaints verified annually during 1975-86, showed a slight upward trend but did not increase significantly. A significant portion of the annual variation in verified complaints-perhaps the best index on severity of the depredation problem was explained by variation in severity of the winter before the depredation season (inverse relation). The addition of a time variable did not account for a significant portion of the remaining variation. Verified complaints of depredations averaged 30 per year, affecting an average of 21 farms (0.33% of producers) annually. Conflicts were highly seasonal and involved primarily cattle (mainly calves), sheep, and domestic turkeys. Annual variation in losses of sheep and turkeys was higher than for cattle. In recent years, sheep and turkey losses in two northwestern counties have increased; preventive control may be warranted in those areas. Site-specific trapping and removal of wolves in response to depredations was the primary control method, resulting in captures of 437 wolves in 12 depredation seasons. For the wolf range as a whole, no relation was found between wolf removal and subsequent depredation rates; however, wolf removal seemed to reduce depredations locally at some farms. When adults and yearlings were removed, no subsequent losses occurred in about 55% of instances; removal of young of the year reduced losses in 22%. Removal of breeding wolves did not reduce the incidence of subsequent losses more than removal of nonbreeding adults and yearlings did. The low number of conflicts for 1975-86 was remarkable considering the frequent contact between wolves and livestock. However, an update of complaints for 1987-89 revealed a definite upward trend in depredations (Epilogue). Improvements in farm management practices may reduce the present number of conflicts.

Resource Publication↗
USGS1991

Testing the Wildlink activity-detection system on wolves and white-tailed deer

We tested the reliability and predictive capabilities of the activity meter in the new Wildlink Data Acquisition and Recapture System by comparing activity counts with concurrent observations of captive wolf (Canis lupus) and free-ranging white-tailed deer (Odocoileus virginianus) activity. The Wildlink system stores activity data in a computer within a radio collar with which a biologist can communicate. Three levels of activity could be detected. The Wildlink system provided greater activity discrimination and was more reliable, adaptable, and efficient and was easier to use than conventional telemetry activity systems. The Wildlink system could be highly useful for determining wildlife energy budgets.

Canadian Journal of Zoology↗
USGS1991

Effects of maternal and grandmaternal nutrition on deer mass and vulnerability to wolf predation

In a Minnesota ecosystem, mass of female white-tailed deer ( Odocoileus virginianus ) fawns and adults, and survival of adult females in the face of wolf ( Canis lupus ) predation, were directly related to maternal nutrition during gestation. Mass of single male fawns produced by 2-year-old females, and survival of yearlings to 2 years of age were related directly to the nutrition of their grandmothers.

Journal of Mammalogy↗
USGS1991

Seroepidemiology of leptospirosis in Minnesota wolves

Serum samples (n = 457) from wolves (Canis lupus) in northern Minnesota were collected from 1972 through 1986 and were tested for antibodies against Leptospira interrogans using a microtiter agglutination test. Twelve serovars included in the study were: australis, autumnalis, ballum, bataviae, bratislava, canicola, copenhageni, grippotyphosa, hardjo, pomona, pyrogenes, and tarassovi. Fifty-two (11%) sera had antibody titers of greater than or equal to 1:50 against one or more serovars of L. interrogans. The seroprevalence of different serovars in decreasing order was: grippotyphosa, bratislava, autumnalis, canicola, pomona, ballum, pyrogenes, hardjo, and copenhageni. No antibodies were found against australis, bataviae, and tarassovi. These results indicate that L. interrogans infection may occur in wolves of Minnesota.

Journal of Wildlife Diseases↗
USGS1991

Dispersal of wolves (Canis lupus) in northeastern Minnesota, 1969-1989

We examined the dispersal patterns of radio-collared wolves (Canis lupus) from 21 packs in the Superior National Forest, Minnesota, from 1969 to 1989. A total of 316 wolves (542 wolf-years) were captured, radio-collared, and followed during 21 years of radio-tracking; 75 were identified as dispersers. Both sexes dispersed equally. Of the adults, yearlings, and pups, 8, 75, and 16%, respectively, dispersed. Most dispersers left when they were 11-12 months old, only a few wolves dispersing as adults. Dispersal occurred mainly in February-April and October-November. Adults dispersed short distances into nearby territories, but yearlings and pups dispersed both short and long distances. Yearling and pup dispersal rates were highest when the wolf population was increasing or decreasing and low when the population was stable. Adults had the highest pairing and denning success, yearlings had moderate pairing and low denning success, and pups had low pairing and denning success. Yearlings and pups that dispersed a short distance had a higher success of settling in a new territory, likely reflecting available vacancies in nearby territories. Thirty-five percent of the known-age wolves remained in their natal territory for >2 years; two wolves were known to have remained for >7 years. The relative weight of pups at capture apparently did not affect their age or success of dispersal or the tendency to disperse.

Canadian Journal of Zoology↗
USGS1991

Wolf predation risk associated with white-tailed deer movements

The survival of 159 yearling and adult deer (Odocoileus virginianus) was monitored by telemetry during 282 spring and 219 fall individual migrations to winter deeryards in northeastern Minnesota. A disproportionate number of deer were killed by wolves (Canis lupus) during fall migration relative to the short time they spent migrating, but not during spring migration. Predation was also significantly greater for male and female yearlings and adult females outside deeryards during winter. Survival of 79 yearlings dispersing from natal ranges was high (1.00). It appears that changing climatic conditions combined with unfamiliar terrain and undetermined factors predispose migratory deer to wolf predation during fall. These findings support an earlier hypothesis that winter yarding is an antipredator strategy.

Canadian Journal of Zoology↗