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Geology topics

M.E. Nelson

Publications and source records attributed to M.E. Nelson.

At least 19 recordsLinked to original sources
USGS2010

Temperature mediated moose survival in Northeastern Minnesota

The earth is in the midst of a pronounced warming trend and temperatures in Minnesota, USA, as elsewhere, are projected to increase. Northern Minnesota represents the southern edge to the circumpolar distribution of moose (Alces alces), a species intolerant of heat. Moose increase their metabolic rate to regulate their core body temperature as temperatures rise. We hypothesized that moose survival rates would be a function of the frequency and magnitude that ambient temperatures exceeded the upper critical temperature of moose. We compared annual and seasonal moose survival in northeastern Minnesota between 2002 and 2008 with a temperature metric. We found that models based on January temperatures above the critical threshold were inversely correlated with subsequent survival and explained >78 of variability in spring, fall, and annual survival. Models based on late-spring temperatures also explained a high proportion of survival during the subsequent fall. A model based on warm-season temperatures was important in explaining survival during the subsequent winter. Our analyses suggest that temperatures may have a cumulative influence on survival. We expect that continuation or acceleration of current climate trends will result in decreased survival, a decrease in moose density, and ultimately, a retreat of moose northward from their current distribution.

Journal of Wildlife Management↗
USGS2008

Spatial interactions of yarded White-tailed Deer, Odocoileus virginianus

We examined the spatial interactions of nine female White-tailed Deer (Odocoileus virginianus) in two deeryards (winter aggregations) in northeastern Minnesota during February-April 1999. Global positioning system (GPS) collars yielded seven pair-wise comparisons of deer that were located at the same time (???1 minute apart) and mat used overlapping areas. Deer traveled separately and did not associate with one another. Within overlapping areas, comparisons of distances between deer and distances between random locations indicated deer moved without regard to each other. Similarly, comparisons of observed and expected probabilities of deer using areas overlapping those of other deer also evinced that deer moved independently.

Canadian Field-Naturalist↗
USGS1996

Wolf management in the 21st century: From public input to sterilization

Human-population increase and land development portend increasing conflict with large predators. Concurrently, changes and diversification of human attitudes are bringing increased disagreement about wildlife management. Animal-rights advocacy resulting from urbanization of human populations conflicts with traditional wildlife management. These forces focus more on wolves than on other wildlife because of strong public and media interest in wolves. Thus wolf management in the future will come under even greater public scrutiny, involve more public input, and may have greater restrictions imposed on it. This will lead to increased complexity in wolf management including more zoning, more experimentation with lethal and non-lethal capture techniques and alternate methods of alleviating damage to pets, livestock, and large ungulate herds, and greater public and private subsidy of wolf damage. One form of non-lethal control of wolf populations that may hold some promise is direct sterilization of males to reduce the biotic potential of the wolf population. Experimental vasectomy of five wild male wolves from four packs in Minnesota indicates that sterile males will continue to hold mates and territories, which would be necessary if sterilization is to be a viable technique for assisting with population control. If sterile males held territories but failed to produce pups, such territories might contain only about a third the number of wolves as fertile pack territories. Because wolves are long-lived in unexploited populations and their territories are large, direct sterilization of relatively few animals each year might significantly reduce populations.

Journal of Wildlife Research↗
USGS1995

Winter range arrival and departure of white-tailed deer in northeastern Minnesota

I analyzed 364 spring and 239 fall migrations by 194 white-tailed deer (Odocoileus virginianus) from 1975 to 1993 in northeastern Minnesota to determine the proximate cause of arrivals on and departures from winter ranges. The first autumn temperatures below -7?C initiated fall migrations for 14% (95% confidence interval (CI) = 0-30) of female deer prior to snowfall in three autumns, but only 2% remained on winter ranges. During 14 autumns, the first temperatures below -7?C coincidental with snowfalls elicited migration in 45% (95% CI = 34-57) of females, and 91 % remained on winter ranges. Arrival dates failed to correlate with independent variables of temperature and snow depth, precluding predictive modeling of arrival on winter ranges. During 13 years, a mean of 80% of females permanently arrived on winter ranges by 31 December. Mean departure dates from winter ranges varied annually (19 March - 4 May) and between winter ranges (14 days) and according to snow depth (15-cm differences). Only 15 - 41 % of deer departed when snow depths were> 30 cm but 80% had done so by the time of lO-cm depths. Mean weekly snow depths in March (18-85 cm) and mean temperature in April (0.3 -8.1 ?c) explained most of the variation in mean departure dates from two winter ranges (Ely, R2 = 0.87, P < 0.0005, n = 19 springs; Isabella, R2 = 0.85, P = 0.0001, n = 12 springs). Mean differences between observed mean departure dates and mean departure dates predicted from equations ranged from 3 days (predictions within the study area) to 8 days (predictions for winter ranges 100-440 km distant).

Minnesota↗
USGS1993

Natal dispersal and gene flow in white-tailed deer in northeastern Minnesota

I documented natal dispersal and gene flow in 79 yearling white-tailed deer ( Odocoileus virginianus ) in northeastern Minnesota during 1974–1988. Sixty-four percent ( n = 28) of 44 males and 20% ( n = 7) of 35 females dispersed from their natal home ranges when 1.0–1.5-years old. Eighty-six percent and 95%, of all yearlings including nondispersers, dispersed ≤26 and ≤38 km, respectively. Minimum gene flow was estimated to be 40 deer per generation, based on a circular subpopulation defined by a 26-km radius. Gene flow estimated from allele frequencies for five polymorphic loci averaged 15 deer per generation among five subpopulations. These values of gene flow were concomitant with significant allelefrequency heterogeneity at the subpopulation level.

Journal of Mammalogy↗
USGS1993

Prey escaping wolves, Canis lupus, despite close proximity

We describe attacks by wolf (Canis lupus) packs in Minnesota on a white-tailed deer (Odocoileus virginianus) and a moose (Alces alces) in which wolves were within contact distance of the prey but in which the prey escaped.

Canadian Field-Naturalist↗
USGS1992

Dispersal in female white-tailed deer

Seven of 35 yearling female white-tailed deer ( Odocoileus virginianus ) in a migratory herd in northeastern Minnesota dispersed 18–168 km from natal ranges during late May through June. Dispersal as a proximate event appears voluntary and independent of deer density.

Journal of Mammalogy↗
USGS1992

Prevalence of antibody titers to leptospira spp. in Minnesota white-tailed deer

Serum samples (n = 204) from 124 white-tailed deer (Odocoileus virginianus) in northeastern Minnesota (USA) were collected from 1984 through 1989 and tested for antibodies to six serovars of Leptospira interrogans (bratislava, canicola, grippotyphosa, hardjo, icterohemorrhagiae, and pomona) using a microtiter agglutination test. Eighty-eight (43%) sera were positive at greater than or equal to 1:100 for antibodies against serovars pomona and/or bratislava; none was positive for any of the other four serovars. None of the 31 sera collected in 1984-85 was positive, whereas all 54 sera collected from 1986 through 1988 had titers of greater than or equal to 1:100. During 1989, only 34 (29%) of 119 sera had titers of greater than or equal to 1:100. Based on these results, we believe there to be wide variability in exposure of Minnesota deer to Leptospira interrogans.

Journal of Wildlife Diseases↗
USGS1991

Spatial heterogeneity of mitochondrial DNA and allozymes among populations of white-tailed deer and mule deer

A white-tailed deer ( Odocoileus virginianus ) population in northeastern Minnesota and a mule deer ( O. hemionus ) population in the Bridger Mountains Montana, have previously been shown to be spatially subdivided into contiguous subpopulations. We assessed the degree of genetic differentiation among subpopulations and tested the hypothesis that differentiation will be greater for mitochondrial DNA (mtDNA) than for nuclear-encoded allozymes. Differentiation of the white-tailed deer subpopulations was significant for two allozyme loci but not for mtDNA, and the overall degree of differentiation was low. Gene flow, recent founding of the subpopulations, and polygamous breeding structure may all have contributed to this pattern. Greater differentiation was evident among disjunct populations than between the contiguous subpopulations of white-tailed deer. The contiguous mule deer subpopulations were significantly differentiated for mtDNA and one allozyme locus. Differentiation was greater for mtDNA than for allozymes. These results are consistent with demographic data that indicate mule deer males disperse more than do females. Disjunct mule deer populations may be similar or dramatically different in mtDNA haplotype frequencies that do not necessarily vary with geographic distance. Current and historical gene flow and breeding structure will influence population genetic patterns.

Journal of Heredity↗
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

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↗
USGS1989

Polygyny in a wild wolf pack

This is the first recorded case of a single free-ranging male wolf breeding two females. The male settled with one at a den. Both females produced pups, and there is some evidence that the pups survived their first winter despite the male's being killed in summer.

Journal of Mammalogy↗
USGS1986

Deer population in the Central Superior National Forest, 1967-1985

Deer were aerially censused each winter from 1976 through 1985 in a 400-sq km2 area near Isabella, Minnesota, in the Central Superior National Forest; a correction factor based on aerial observability of radio-tagged deer in the same region was then applied to the census figures. Deer numbers, which had reached an estimated 3.5/sq km, declined drastically in the early 1970's, fluctuated between about 0.43 and 0.97/sq km from 1976 through 1985, and began increasing in 1983.

Research Paper↗