23 research outputs found

    DYNAMICS, MOVEMENTS, AND FEEDING ECOLOGY OF A NEWLY PROTECTED WOLF POPULATION IN NORTHWESTERN MINNESOTA

    Get PDF
    The gray wolf Canis lupus occupies only about 1 percent of its former range in the lower 48 states (Mech 1974a). Most of the range is in northern Minnesota, where the resident population is classified as threatened by the U.S. Department of the Interior. Wolves have been and will continue to be the subject of considerable controversy in Minnesota. The first scientific study of wolves in Minnesota was conducted by Olson (1938a,b). That and all subsequent re- search was in the Superior National Forest (SNF) of northeastern Minnesota even though wolves inhabit approximately the northern third of the state. Consequently, until the present study, little was known about wolves in northwestern Minnesota, although it is highly desirable to have such information if wolves throughout Minnesota are to be managed wisely

    Wolves and Humans

    Get PDF
    TRY TO IMAGINE a small group of wolves sitting at a table engaged in vigorous debate. These wolves are from various parts of the globe and are perhaps a bit more scholarly than most. In fact, they are especially knowledgeable about the biology of that notorious two-legged species, Homo sapiens. They have been brought together to document their relationship with humans over the last several millennia. Pause for a few moments and consider what they might say ... Perhaps the wolves\u27 discussion would chronicle the evils of the human species, including details of atrocities committed against lupine ancestors down through the centuries. They might discuss the bizarre workings of the human imagination and the hopeless confusion of fact and fiction about wolf relationships with humans. The discussion might also express admiration for the way early humans respected wolves and imitated their living in family bands, maintaining pair bonds for years at a time, communicating in complex ways, and hunting cooperatively. The effects of advances in human technology might be detailed. The recent and long-awaited legal protection for wolves and the soaring popularity of wolves among some humans would certainly deserve mention. After an exhaustive review of the wolf-human relationship, the wolves might finally conclude that it has taken so many forms, depending on time and place, that generalizations are impossible

    WOLF DISTRIBUTION AND ROAD DENSITY IN MINNESOTA

    Get PDF
    Distribution of the wolf (Canis lupus) in parts of Wisconsin (Thiel 1985) and Michigan and Ontario (Jensen et al. 1986) has been related to the density of roads passable by 2-wheel-drive vehicles. Wolves in those regions generally do not occur where road densities exceed 0.58 km/km2, whereas similar areas nearby with fewer roads do contain wolves. In a small segment of the wolf range in Minnesota, wolves did not have territories where roads exceeded a density of 0.73 km/km2 (T. K. Fuller, Minn. Dep. Nat. Resour., unpubl. data). In another small area of Minnesota with 0.73 km of roads/ km2, \u3e50% of known wolf mortality was caused by humans despite prohibitions of the Endangered Species Act, but wolves survived there probably because the area was surrounded by an extensive wilderness reservoir (L. D. Mech, un-publ. data)

    WOLF DISTRIBUTION AND ROAD DENSITY IN MINNESOTA

    Get PDF
    Distribution of the wolf (Canis lupus) in parts of Wisconsin (Thiel 1985) and Michigan and Ontario (Jensen et al. 1986) has been related to the density of roads passable by 2-wheel-drive vehicles. Wolves in those regions generally do not occur where road densities exceed 0.58 km/km2, whereas similar areas nearby with fewer roads do contain wolves. In a small segment of the wolf range in Minnesota, wolves did not have territories where roads exceeded a density of 0.73 km/km2 (T. K. Fuller, Minn. Dep. Nat. Resour., unpubl. data). In another small area of Minnesota with 0.73 km of roads/ km2, \u3e50% of known wolf mortality was caused by humans despite prohibitions of the Endangered Species Act, but wolves survived there probably because the area was surrounded by an extensive wilderness reservoir (L. D. Mech, un-publ. data)

    An Unparalleled Opportunity for an Important Ecological Study

    Get PDF
    Wolves (Canis lupus) and moose (Alces americanus) have been studied since 1958 on 540-squarekilometer Isle Royale National Park, in Lake Superior. Wolves arrived there across the ice around 1949, and the population once increased to about 50, averaging about 25 annually (Mech 1966, Jordan et al. 1967, Vucetich and Peterson 2009). However, for various reasons, wolf numbers there have now dwindled to 2 nonbreeders, and the US National Park Service has proposed reintroducing 20–30 wolves over 3 years (National Park Service 2016). This situation offers an unparalleled opportunity to promote science-based management of this unique national park. The park has long been in the public eye for its world-renowned wolf and moose populations. Visitors to this island wilderness are especially interested in the scientific studies it has yielded and in maintaining its ecosystem

    The Life Cycle of Instability Features Measured from the Andes Lidar Observatory Over Cerro Pachon on 24 March 2012

    Get PDF
    The Aerospace Corporation\u27s Nightglow Imager (ANI) observes nighttime OH emission (near 1.6 µm) every 2 s over an approximate 73¬∞ field of view. ANI had previously been used to study instability features seen over Maui. Here we describe observations of instabilities seen from 5 to 8 UT on 24 March 2012 over Cerro Pachon, Chile, and compare them with previous results from Maui, with theory, and with Direct Numerical Simulations (DNS). The atmosphere had reduced stability because of the large negative temperature gradients measured by a Na lidar. Thus, regions of dynamical and convective instabilities are expected to form, depending on the value of the Richardson number. Bright primary instabilities are formed with a horizontal wavelength near 9 km and showed the subsequent formation of secondary instabilities, rarely seen over Maui, consistent with the primaries being dynamical instabilities. The ratio of the primary to secondary horizontal wavelength was greater over Chile than over Maui. After dissipation of the instabilities, smaller-scale features appeared with sizes in the buoyancy subrange between 1.5 and 6 km. Their size spectra were consistent with the model of Weinstock (1978) if the turbulence is considered to be increasing. The DNS results produce secondary instabilities with sizes comparable to what is seen in the images although their spectra are somewhat steeper than is observed. However, the DNS results also show that after the complete decay of the primary features, scale sizes considerably smaller than 1 km are produced and these cannot be seen by the ANI instrument

    Anthropogenic Aerosols Cause Recent Pronounced Weakening of Asian Summer Monsoon Relative to Last Four Centuries

    Get PDF
    The Asian Summer Monsoon (ASM) affects ecosystems, biodiversity, and food security of billions of people. In recent decades, ASM strength (as represented by precipitation) has been decreasing, but instrumental measurements span only a short period of time. The initiation and the dynamics of the recent trend are unclear. Here for the first time, we use an ensemble of 10 tree ring-width chronologies from the west-central margin of ASM to reconstruct detail of ASM variability back to 1566 CE. The reconstruction captures weak/strong ASM events and also reflects major locust plagues. Notably, we found an unprecedented 80-year trend of decreasing ASM strength within the context of the 448-year reconstruction, which is contrary to what is expected from greenhouse warming. Our coupled climate model shows that increasing anthropogenic sulfate aerosol emissions over the Northern Hemisphere could be the dominant factor contributing to the ASM decrease. Plan Language Summary Monsoonal rainfall has a certain influence on agriculture and industry in the regions of Asian Summer Monsoon (ASM). An understanding of the spatial-temporal variability of the ASM and the associated dynamics is vital for terrestrial ecosystems, water resources, forests, and landscapes. We have developed a 448-year ASM reconstruction back to 1566 CE using 10 tree ring chronologies from the margin region of ASM. We find that historical severe droughts and locust plague disasters during weak ASM events. The recent decreasing ASM trend persisting for over 80 years is unprecedented over the past 448 years. Coupled climate models show that increasing anthropogenic aerosol emissions are the dominant underlying factor. Our aim is that the time series will find a wide range of utility for understanding past climate variability and for predicting future climate change.National Natural Science Foundation of China [41630531]; National Research Program for Key Issues in Air Pollution Control [DQGG0104]; Chinese Academy of Sciences [QYZDJ-SSW-DQC021, XDPB05, GJHZ1777]; Institute of Earth Environment, Chinese Academy of Sciences; State Key Laboratory of Loess and Quaternary Geology6 month embargo; first published: 09 April 2019This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

    Detector Fabrication Yield for SuperCDMS Soudan

    Get PDF
    The SuperCDMS collaboration is presently operating a 9 kg Ge payload at the Soudan Underground Laboratory in their direct search for dark matter. The Ge detectors utilize double-sided athermal phonon sensors with an interdigitated electrode structure (iZIPs) to reject near-surface electron-recoil events. These detectors each have a mass of 0.6 kg and were fabricated with photolithographic techniques. The detector fabrication advances required and the production yield encountered are described.United States. Dept. of EnergyNational Science Foundation (U.S.

    Demonstration of surface electron rejection with interleaved germanium detectors for dark matter searches

    Full text link
    The following article appeared in Applied Physics Letters 103.16 (2013): 164105 and may be found at http://scitation.aip.org/content/aip/journal/apl/100/26/10.1063/1.4729825The SuperCDMS experiment in the Soudan Underground Laboratory searches for dark matter with a 9-kg array of cryogenic germanium detectors. Symmetric sensors on opposite sides measure both charge and phonons from each particle interaction, providing excellent discrimination between electron and nuclear recoils, and between surface and interior events. Surface event rejection capabilities were tested with two 210 Pb sources producing ∼130 beta decays/hr. In ∼800 live hours, no events leaked into the 8–115 keV signal region, giving upper limit leakage fraction 1.7 × 10−5 at 90% C.L., corresponding to < 0.6 surface event background in the future 200-kg SuperCDMS SNOLAB experiment.This work is supported in part by the National Science Foundation (Grant Nos. AST-9978911, NSF-0847342, PHY-1102795,NSF-1151869, PHY-0542066, PHY-0503729, PHY-0503629, PHY-0503641, PHY-0504224, PHY-0705052,PHY-0801708, PHY-0801712, PHY-0802575, PHY-0847342, PHY-0855299, PHY-0855525, and PHY-1205898), by the Department of Energy (Contract Nos. DE-AC03-76SF00098, DE-FG02-92ER40701, DE-FG02-94ER40823,DE-FG03-90ER40569, DE-FG03-91ER40618, and DESC0004022),by NSERC Canada (Grant Nos. SAPIN 341314 and SAPPJ 386399), and by MULTIDARK CSD2009-00064 and FPA2012-34694. Fermilab is operated by Fermi Research Alliance, LLC under Contract No. De-AC02-07CH11359, while SLAC is operated under Contract No. DE-AC02-76SF00515 with the United States Department of Energy

    Reconstructing 800 years of summer temperatures in Scotland from tree rings

    Get PDF
    We thank The Carnegie Trust for the Universities of Scotland for providing funding for Miloš Rydval’s PhD. The Scottish pine network expansion has been an ongoing task since 2007 and funding must be acknowledged to the following projects: EU project ‘Millennium’ (017008-2), Leverhulme Trust project ‘RELiC: Reconstructing 8000 years of Environmental and Landscape change in the Cairngorms (F/00 268/BG)’ and the NERC project ‘SCOT2K: Reconstructing 2000 years of Scottish climate from tree rings (NE/K003097/1)’.This study presents a summer temperature reconstruction using Scots pine tree-ring chronologies for Scotland allowing the placement of current regional temperature changes in a longer-term context. ‘Living-tree’ chronologies were extended using ’subfossil’ samples extracted from nearshore lake sediments resulting in a composite chronology > 800 years in length. The North Cairngorms (NCAIRN) reconstruction was developed from a set of composite blue intensity high-pass and ring-width low-pass chronologies with a range of detrending and disturbance correction procedures. Calibration against July-August mean temperature explains 56.4% of the instrumental data variance over 1866-2009 and is well verified. Spatial correlations reveal strong coherence with temperatures over the British Isles, parts of western Europe, southern Scandinavia and northern parts of the Iberian Peninsula. NCAIRN suggests that the recent summer-time warming in Scotland is likely not unique when compared to multi-decadal warm periods observed in the 1300s, 1500s, and 1730s, although trends before the mid-16th century should be interpreted with some caution due to greater uncertainty. Prominent cold periods were identified from the 16th century until the early 1800s – agreeing with the so-called Little Ice Age observed in other tree-ring reconstructions from Europe - with the 1690s identified as the coldest decade in the record. The reconstruction shows a significant cooling response one year following volcanic eruptions although this result is sensitive to the datasets used to identify such events. In fact, the extreme cold (and warm) years observed in NCAIRN appear more related to internal forcing of the summer North Atlantic Oscillation.Publisher PDFPeer reviewe
    corecore