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Grand Rapids, MN, United States

Kouffeld M.J.,University of Minnesota | Larson M.A.,Forest Wildlife Populations and Research Group | Gutierrez R.J.,University of Minnesota
Journal of Wildlife Management | Year: 2013

We studied the habitat relationships of male ruffed grouse (Bonasa umbellus) at the landscape scale when grouse were at the peak of their population cycle. We located 290 and 230 male grouse during 2009 and 2010, respectively, on 30 landscapes encompassing 5,349 ha. We used an information-theoretic model selection approach to examine 2 sets of a priori models. We designed our first model set to evaluate the relationships between Shannon's evenness index of cover types and grouse density and our second set to evaluate other relationships between grouse density and landscape configuration. The top model in the first set was a null model (intercepts only), but a competing model indicated that Shannon's evenness index was positively correlated with male grouse density (r = 0.43). Shannon's evenness index was confounded with cover type dominance in landscapes because it was positively correlated (r = 0.55) with the proportion of the aspen cover type and negatively correlated (r = -0.79) with the proportion of the conifer cover type. The top-ranked model from our second model set included only year and road density. Road density was negatively related to grouse density (r = -0.34), which could mean either hunting pressure along roads affected density or cover types were different in landscapes with greater road densities. The year-only model indicated that male grouse density was less in 2010 than in 2009 (βyear = -0.014, 95% CI = -0.024 to -0.005). We predict that forest management practices that result in an even distribution of cover types within landscapes should result in greater densities of grouse. © 2013 The Wildlife Society. Source

Severud W.J.,University of Minnesota | Delgiudice G.D.,University of Minnesota | Delgiudice G.D.,Forest Wildlife Populations and Research Group
Journal of Wildlife Diseases | Year: 2016

North American moose (Alces americanus) frequently become infested with winter ticks (Dermacentor albipictus). During capture of neonatal moose in northeastern Minnesota, US, in May-June 2013 and 2014, we recovered adult ticks from neonates, presumably vertically transferred from dams, heretofore, not documented. Infestations on neonates may have population-level implications. © Wildlife Disease Association 2016. Source

Roy C.L.,Wetland Wildlife Populations and Research Group | Roy C.L.,Forest Wildlife Populations and Research Group | St-Louis V.,Wildlife Biometrics Unit | House J.,Bemidji State University
Biological Invasions | Year: 2016

The introduction of the invasive faucet snail (Bithynia tentaculata) and its associated trematodes, Cyathocotyle bushiensis, Sphaeridiotrema spp., and Leyogonimus polyoon, has resulted in recurring waterfowl die-offs during spring and fall migration in the Great Lakes Region, especially of Lesser scaup (Aythya affinis) and American coots (Fulica americana). Here we evaluated faucet snail habitat use and abundance in infested waterbodies in northcentral Minnesota (USA) during spring, summer, and fall of 2011–2013. We collected snail samples, along with data on abiotic and biotic variables, at 12 snail-infested waterbodies. We used Generalized Estimating Equations to develop models that explain variability in the distribution and abundance of snails within waterbodies. Models containing water depth consistently received considerable support in waterbodies where depth varied substantially; however the specific shape of these relationships varied among waterbodies. Snails used a wide range of depths, but were more likely to be present in deep portions (~6 m) of large lakes in all seasons. We found seasonal differences in the location of rafts of migrating scaup, with use of areas closer to shore in the spring, and use of areas shallower than those used most by faucet snails. Patterns in snail distribution likely influenced the availability of snails for consumption by migrating waterfowl; differences in portions of large lakes used by migratory waterfowl as stopover sites and by faucet snails may reduce exposure of migrating waterfowl to trematodes in infested lakes. However, some spatio-temporal overlap between snails and scaup occurs and explains the continuing loss of waterfowl to trematodiasis. © 2016 Springer International Publishing Switzerland Source

Puckett E.E.,University of Missouri | Kristensen T.V.,University of Arkansas | Wilton C.M.,Mississippi State University | Lyda S.B.,Oklahoma State University | And 7 more authors.
Molecular Ecology | Year: 2014

Bottlenecks, founder events, and genetic drift often result in decreased genetic diversity and increased population differentiation. These events may follow abundance declines due to natural or anthropogenic perturbations, where translocations may be an effective conservation strategy to increase population size. American black bears (Ursus americanus) were nearly extirpated from the Central Interior Highlands, USA by 1920. In an effort to restore bears, 254 individuals were translocated from Minnesota, USA, and Manitoba, Canada, into the Ouachita and Ozark Mountains from 1958 to 1968. Using 15 microsatellites and mitochondrial haplotypes, we observed contemporary genetic diversity and differentiation between the source and supplemented populations. We inferred four genetic clusters: Source, Ouachitas, Ozarks, and a cluster in Missouri where no individuals were translocated. Coalescent models using approximate Bayesian computation identified an admixture model as having the highest posterior probability (0.942) over models where the translocation was unsuccessful or acted as a founder event. Nuclear genetic diversity was highest in the source (AR = 9.11) and significantly lower in the translocated populations (AR = 7.07-7.34; P = 0.004). The Missouri cluster had the lowest genetic diversity (AR = 5.48) and served as a natural experiment showing the utility of translocations to increase genetic diversity following demographic bottlenecks. Differentiation was greater between the two admixed populations than either compared to the source, suggesting that genetic drift acted strongly over the eight generations since the translocation. The Ouachitas and Missouri were previously hypothesized to be remnant lineages. We observed a pretranslocation remnant signature in Missouri but not in the Ouachitas. © Published 2014. This article is a U.S. Government work and is in the public domain in the USA. Source

Fieberg J.,Wildlife Biometrics Unit | DelGiudice G.D.,Forest Wildlife Populations and Research Group | DelGiudice G.D.,University of Minnesota
Environmental and Ecological Statistics | Year: 2011

We illustrate 2 techniques for estimating age-specific hazards with wildlife telemetry data: Siler's (Ecology 60:750-757, 1979) competing risk model fit using maximum likelihood and a penalized likelihood estimate that only assumes the hazard varies smoothly with age. In most telemetry studies, animals enter at different points in time (and at different ages), leading to data that are left-truncated. In addition, death times may only be known to occur within an interval of time (interval-censoring). Observations may also be right-censored (e. g., due to the end of the study, radio-collar failure, or emigration from the study area). It is important to consider the observation process, since the contribution of each individual's data to the likelihood will depend on whether data are left-truncated or censored. We estimate age-specific hazards using telemetry data collected in two Phases during a 13-year study of white-tailed deer (Odocoileus virginianus) in northern Minnesota. The hazards estimated from the two methods were similar for the full data set that included 302 adults and 76 neonates (followed since or shortly after birth). However, estimated hazards for early-aged individuals differed considerably for subsets of the data that did not include neonates. We discuss the advantages and disadvantages of these two modeling approaches and also compare the estimators using a short simulation study. © 2009 Springer Science+Business Media, LLC. Source

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