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Filters: Tags: Yukon Territory (X) > Types: Downloadable (X)

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Nine native taxa including Carex oligosperma, C. pauciflora, C. pellita, Chimaphila umbellata ssp. occidentalis, Draba densifolia, x Elyleymus hirtiflorus, Eriophorum vaginatum ssp. spissum, Impatiens ? capensis, and Rhus radicans are reported new to the known flora of the Yukon Territory. Eight introduced taxa are also reported as new to the known flora. Significant range extensions within the Territory are reported for 180 native and 17 introduced taxa. Comments are presented on three native taxa and two native taxa are deleted from the Territory.
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Ten native taxa including Arabis boivinii, Carex aquatilis ssp. stans, Descurainia incisa var. incisa, Draba lonchocarpa var. vestita, Isoetes maritima, Lepidium densiflorum var. macrocarpum, Malaxis paludosa, Phyllodoce X intermedia, Scirpus acutus, Stipa hymenoides and Taraxacum carneocoloratum are reported new to the known flora of the Yukon Territory. Three introduced taxa including Centaurea cyanus, Lolium perenne ssp. multiflorum, Rheum rhaponticum and Sorbaria sorbifolia are also reported as new to the known flora. Significant range extensions within the Territory are reported for 127 native and 21 introduced taxa and comments are presented on four native taxa. Of these, 10 native and three introduced are...
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Reflectance data from HyMap™ were processed using the Material Identification and Characterization Algorithm (MICA), a module of the USGS PRISM (Processing Routines in IDL for Spectroscopic Measurements) software (Kokaly, 2011), programmed in Interactive Data Language (IDL; Harris Geospatial Solutions, Broomfield, Colorado). The HyMap reflectance data are provided and described in this data release. MICA identifies the spectrally predominant mineral(s) in each pixel of imaging spectrometer data by comparing continuum-removed spectral features in the pixel’s reflectance spectrum to continuum-removed absorption features in reference spectra of minerals, vegetation, water, and other materials. Linear continuum removal...
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Detailed geologic mapping and sample collection was conducted in rare bedrock exposures of the Denali fault zone during the summer months of 2013, 2014, and 2015 by the U.S. Geological Survey. Data include measurements of structural geologic orientations and documentation of fault zone and host rock characteristics. Representative samples were selected for measurements of fault vein attributes and electron backscatter diffraction studies to characterize deformation mechanisms. All station locations, pertinent sample information, and associated data are included in this data release.
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We studied kill rates by wolves (Canis lupus) on a rapidly growing moose population in the east-central Yukon. We added these data to the cumulative functional response curve obtained in other North American wolf studies. Our kill rates are higher than those predicted at low moose densities. The kill rate increases rapidly, reaching 2.4 moose per wolf per 100 days at 0.26 moose/km2 and remains constant at this level. No data are available below 0.2 moose/km2 to indicate the shape of the ascending curve. Based on moose distribution and the low prey-switching ability of wolves, we suggest that the functional response curve is of type II. Our wolf predation rate model predicts that moose are held to a low density equilibrium...
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We studied the kill rate by wolves (Canis lupus) after a large-scale wolf removal when populations of wolves, moose (Alces alces), and woodland caribou (Rangifer tarandus caribou) were all increasing. We followed a total of 21 wolf packs for 4 winters, measuring prey selection, kill rates, and ecological factors that could influence killing behavior. Wolf predation was found to be mainly additive on both moose and caribou populations. Kill rates by individual wolves were inversely related to pack size and unrelated to prey density or snow depth. Scavenging by ravens decreased the amount of prey biomass available for wolves to consume, especially for wolves in smaller packs. The kill rate by wolves on moose calves...
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A map of the wavelength position of the white mica 2,200 nanometer (nm) Al-OH absorption feature was compiled for a region of Nabesna, Alaska, using HyMap™ reflectance data provided and described in this data release. White mica wavelength position was computed for each pixel with spectrally predominant muscovite or illite. The computation was made using a function of the USGS PRISM (Processing Routines in IDL for Spectroscopic Measurements) software (Kokaly, 2011), programmed in Interactive Data Language (IDL; Harris Geospatial Solutions, Broomfield, Colorado). The PRISM function applies linear continuum-removal (Clark and Roush, 1984) to the 2,200 nm feature and fits a parabola to three channels: the channel...
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A hormonal-challenge protocol was used to compare the stress response of males of Arctic ground squirrels and red squirrels during the breeding season (May). These squirrels live in the same boreal forest of the Yukon, but have very different life histories and utilize the forest in markedly different ways. Red squirrels had levels of total cortisol, maximum corticosteroid-binding capacity, and free cortisol that were 5, 7, and 2 times, respectively, those of Arctic ground squirrels. Red squirrels were resistant to suppression by an artificial glucocorticoid, dexamethasone (DEX); Arctic ground squirrels were not. Cortisol levels in red squirrels responded slowly but continuously to the ACTH injection; Arctic ground...
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Corescan© Hyperspectral Core Imager Mark III (HCI-III) system data were acquired for hand samples, and subsequent billets made from the hand samples, collected during the U.S. Geological Survey (USGS) 2014, 2015, and 2016 field seasons in the Nabesna area of the eastern Alaska Range. This area contains exposed porphyry deposits and hand samples were collected throughout the region in support of the HyMap imaging spectrometer survey (https://doi.org/10.5066/F7DN435W) (Kokaly and others, 2017a). The HCI-III system consists of three different components. The first is an imaging spectrometer which collects reflectance data with a spatial resolution of approximately 500 nanometers (nm) for 514 spectral channels covering...
Categories: Data; Types: Downloadable, Map Service, OGC WFS Layer, OGC WMS Layer, OGC WMS Service, Shapefile; Tags: Alaska, Alaska, Alaska Range, Bond Creek, Canada, All tags...
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There are few quick, precise indices for predicting population size of semifossorial mammals. We assessed the utility of powder-tracing and infrared thermal imaging to predict population size in the Arctic ground squirrel (Spermophilus parryii) in the boreal forest of southwestern Yukon. Density estimated from livetrapping was strongly and linearly correlated with both indices (r = 0.81 for powder-tracking; r = 0.91 for infrared imaging). The slope of the relationship between density and the infrared index (0.10) deviated from a slope of 1. The slope of the relationship between density and the powder-tracking index (0.82) did not deviate from a slope of 1, but our power to detect departures from this slope using...
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The distribution and prevalence of mandibular osteomyelitis, lumpy jaw, and other dental anomalies in wild sheep were investigated and their biological and evolutionary implications were assessed. Our survey was based on 3,363 mandibles of wild sheep and 1,028 from domesticated varieties. Lumpy jaw is widespread in wild sheep of North America, but it is rare or absent in wild sheep from Eurasia. Among the subspecies of Ovis spp. in North American, the thinhorn sheep (Ovis dalli) were the most seriously impacted, with a prevalence in Dall's sheep (O. dalli dalli) of 23.3% and 29.3% in Stone's sheep (O. dalli stonei). Among the bighorns (O. canadensis), the Rocky Mountain subspecies (O. canadensis canadensis) had...
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The diversity of Agromyzidae (Diptera) associated with disjunct xeric grasslands was studied at six south-facing slopes in the southern Yukon Territory, Canada. Agromyzidae was the most diverse of 32 families of Brachycera at the sites, with 34 species (485 specimens) collected. Eight new species are described: Liriomyza nares sp.nov., Metopomyza adretana sp.nov., Phytoliriomyza depricei sp.nov., Phytoliriomyza triangulata sp.nov., Phytomyza conglomerata sp.nov., Phytomyza dioni sp.nov., Phytomyza klondikensis sp.nov., and Phytomyza takhiniensis sp.nov. Twenty previously described species were identified and six other unnamed species were represented by females only. Fourteen of the 20 previously described species...
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We examined whether arctic ground squirrel (Spermophilus parryii plesius) populations in northern boreal forest in the Yukon Territory, Canada, were limited by food, predators, or a combination of both, during the decline and low phases of a snowshoe hare cycle. From 1990 to 1995, populations were monitored in large-scale (1 km2) experimental manipulations. Squirrels were studied on eight 9-ha grids: four unmanipulated control grids, two food-supplemented grids, a predator-exclosure grid, and a predator-exclosure + food-supplemented grid. Population density was measured on all grids by livetrapping and active-season survival was measured using radiotelemetry. Population densities were lowest in 1992 and 1993 (2...
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The 10-year cycle of abundance in the snowshoe hare, Lepus americanus, is one of the most striking features of the ecology of the boreal forests. Ten-year snowshoe-hare cycles in Canada were first analyzed quantitatively by wildlife biologists in the 1960s, using the meticulous fur-trading records of the Hudson Bay Company, which was founded in 1671. The rise and fall in the Canada lynx, a specialist predator of snowshoe hares, was shown to mirror the rise and fall of its prey population. Cycles appear to challenge the implicit assumption that there is a balance in nature. Large-scale experiments in the Yukon have shown that the snowshoe-hare cycle is a product of an interaction between predation and food supply,...
    map background search result map search result map Contrasting stress response of male arctic ground squirrels and red squirrels Experimental manipulation of predation and food supply of arctic ground squirrels in the boreal forest New records of vascular plants in the Yukon Territory II Kill rate by wolves on moose in the Yukon Wolf functional response and regulation of moose in the Yukon Indices of population size for burrowing mammals Diversity of Agromyzidae (Diptera) [leafmining flies] in disjunct grasslands of the southern Yukon Territory New records of vascular plants in the Yukon territory III Lumpy jaw in wild sheep and its evolutionary implications What Drives the 10-Year Cycle of Snowshoe Hares? Mineral predominance map for Nabesna, Alaska, derived from imaging spectrometer reflectance data Corescan© Hyperspectral Core Imager, Mark III system data collected for the characterization of mineral resources near Nabesna, Alaska, 2014-2016 White mica wavelength position map for Nabesna, Alaska, derived from imaging spectrometer reflectance data Denali Fault Zone Field, Microvein, and Microbeam Data, Kluane Ranges, Yukon, Canada Wolf functional response and regulation of moose in the Yukon Corescan© Hyperspectral Core Imager, Mark III system data collected for the characterization of mineral resources near Nabesna, Alaska, 2014-2016 Mineral predominance map for Nabesna, Alaska, derived from imaging spectrometer reflectance data White mica wavelength position map for Nabesna, Alaska, derived from imaging spectrometer reflectance data Diversity of Agromyzidae (Diptera) [leafmining flies] in disjunct grasslands of the southern Yukon Territory Denali Fault Zone Field, Microvein, and Microbeam Data, Kluane Ranges, Yukon, Canada Kill rate by wolves on moose in the Yukon Lumpy jaw in wild sheep and its evolutionary implications Contrasting stress response of male arctic ground squirrels and red squirrels Experimental manipulation of predation and food supply of arctic ground squirrels in the boreal forest Indices of population size for burrowing mammals What Drives the 10-Year Cycle of Snowshoe Hares? New records of vascular plants in the Yukon Territory II New records of vascular plants in the Yukon territory III