White T.,Pennsylvania State University |
Bradley D.,4210 University Drive |
Haeussler P.,4210 University Drive |
Rowley D.B.,University of Chicago
Journal of Geology | Year: 2017
An intensely weathered paleosol representing a nearly isochronous landscape exists at many places in continental Late Paleocene–Early Eocene strata in North America. Most commonly, a single siderite spherule–bearing horizon is found, from which δ18O values were obtained to construct a paleolatitudinal gradient for Late Paleocene–Early Eocene North America. Comparison of the paleosol siderite spherule δ18O composition from the displaced Yakutat Terrane of Alaska to the North American paleolatitudinal gradient indicates that during the Late Paleocene–Early Eocene the terrane existed at ∼44° paleonorth, thus supporting hypotheses for a far-traveled terrane history. © 2017 by The University of Chicago.
Lemons P.R.,University of Nevada, Reno |
Lemons P.R.,4210 University Drive |
Sedinger J.S.,University of Nevada, Reno |
Herzog M.P.,University of Nevada, Reno |
And 3 more authors.
Journal of Mammalogy | Year: 2010
Analyses of feces, stomach contents, and regurgitated pellets are common techniques for assessing diets of vertebrates and typically contain more than 1 food item per sampling unit. When analyzed, these individual food items have traditionally been treated as independent, which represents pseudoreplication. When food types are recorded as present or absent, these samples can be treated as multinomial vectors of food items, with each vector representing 1 realization of a possible diet. We suggest such data have a similar structure to capture histories for closed-capture, capturemarkrecapture data. To assess the effects of landscapes and presence of a potential competitor, we used closed-capture models implemented in program MARK into analyze diet data generated from feces of swift foxes (Vulpes velox) and coyotes (Canis latrans) in northwestern Texas. The best models of diet contained season and location for both swift foxes and coyotes, but year accounted for less variation, suggesting that landscape type is an important predictor of diets of both species. Models containing the effect of coyote reduction were not competitive (ΔQAICc 53.6685), consistent with the hypothesis that presence of coyotes did not influence diet of swift foxes. Our findings suggest that landscape type may have important influences on diets of both species. We believe that multinomial models represent an effective approach to assess hypotheses when diet studies have a data structure similar to ours. © 2010 American Society of Mammalogists.
West D.P.,Middlebury College |
Bradley D.C.,4210 University Drive |
Coish R.A.,Middlebury College
Atlantic Geology | Year: 2016
The Litchfield pluton is a poorly exposed 7 km2 composite alkalic intrusive complex that cuts previously deformed and metamorphosed Silurian turbidites in south-central Maine. The pluton includes a variety of alkaline syenites, including the type locality of “litchfieldite,” a coarse-grained cancrinite-, sodalite-, and lepidomelane-bearing nepheline syenite first recognized over 150 years ago and common in many petrologic collections. A new U-Pb zircon age of 321 ± 2 Ma from the nepheline syenite is interpreted to represent the crystallization age of the plutonic complex. A new biotite40Ar/39Ar age of 239 ± 1 Ma from the syenite is similar to previously published mica ages from the surrounding country rocks and dates the time of regional cooling in the area below ~ 300°C. Whole-rock chemical analyses of rocks of the Litchfield pluton reveal silica-undersaturated alkaline compositions that are consistent with formation in a within-plate tectonic setting. The age and geochemical characteristics of the alkalic igneous rocks near Litchfield are consistent with a model that invokes the generation of a small volume of alkalic magma beneath south-central Maine during a period of Carboniferous transcurrent tectonism in the northern Appalachian orogen. © Atlantic Geology, 2016.
Toussaint R.K.,Alaska Pacific University |
Sage G.K.,4210 University Drive |
Talbot S.L.,4210 University Drive |
Scheel D.,Alaska Pacific University
Conservation Genetics Resources | Year: 2012
We isolated and developed 18 novel microsatellite markers for the giant Pacific octopus (Enteroctopus dofleini) and examined them for 31 individuals from Prince William Sound (PWS), Alaska. These loci displayed moderate levels of allelic diversity (averaging 11 alleles per locus) and heterozygosity (averaging 65%). Seven loci deviated from Hardy-Weinberg Equilibrium (HWE) due to heterozygote deficiency for the PWS population, although deviations were not observed for all these loci in other populations, suggesting the PWS population is not in mutation-drift equilibrium. These novel microsatellite loci yielded sufficient genetic diversity for potential use in population genetics, individual identification, and parentage studies. © 2011 Springer Science+Business Media B.V. (outside the USA).
Sexson M.G.,4210 University Drive |
Mulcahy D.M.,4210 University Drive |
Spriggs M.,Mesker Park Zoo and Botanic Garden |
Myers G.E.,6515 Mohican Drive
Journal of Wildlife Management | Year: 2014
Surgically implanted transmitters are a common method for tracking animal movements. Immediately following surgical implantation, animals pass through a critical recovery phase when behaviors may deviate from normal and the likelihood of individual survival may be reduced. Therefore, data collected during this period may be censored to minimize bias introduced by surgery-related behaviors or mortality. However, immediate post-release mortalities negate a sampling effort and reduce the amount of data potentially collected after the censoring period. Wildlife biologists should employ methods to support an animal's survival through this period, but factors contributing to immediate post-release survival have not been formally assessed. We evaluated factors that potentially influenced the immediate post-release survival of 56 spectacled eiders (Somateria fischeri) marked with coelomically implanted satellite transmitters with percutaneous antennae in northern Alaska in 2010 and 2011. We modeled survival through the first 14 days following release and assessed the relative importance and effect of 15 covariates hypothesized to influence survival during this immediate post-release period. Estimated daily survival rate increased over the duration of the immediate post-release period; the probability of mortality was greatest within the first 5 days following release. Our top-ranking model included the effect of 2 blood analytes, pH and hematocrit, measured prior to surgical implantation of a transmitter. We found a positive response to pH; eiders exhibiting acidemia (low pH) prior to surgery were less likely to survive the immediate post-release period. We found a curvilinear response to hematocrit; eiders exhibiting extremely low or high pre-surgery hematocrit were also less likely to survive the immediate post-release period. In the interest of maximizing the survival of marked birds following release, hematological data obtained prior to surgical implantation of telemetry equipment may be useful when screening for optimal surgical candidates or informing appropriate response to mitigate potentially deleterious disorders such as acidemia. Published 2014. This article is a U.S. Government work and is in the public domain in the USA. © 2014 The Wildlife Society.