Filters: Tags: Ursus arctos (X)
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Over the past two centuries, persecution and habitat loss caused grizzly bears (Ursus arctos) to decline from a population of approximately 50,000 individuals to only 4 fragmented populations within the continental United States. In recent decades, these populations have increased and expanded in size and range due to collaborative conservation efforts and protections under the Endangered Species Act. Today, population estimates exceed 1000 animals each in the Northern Continental Divide Ecosystem (NCDE) and Greater Yellowstone Ecosystem (GYE). The Selkirk Ecosystem (SE) has approximately 50 grizzly bears, and augmentations into the Cabinet-Yaak Ecosystem (CYE) helped boost the population to an estimated 50 – 60...
We evaluate mortalities for population segments within the DMA by deriving estimates of total mortality for independent-age (≥2 years old) females and independent-age males, including estimates of unknown/unreported mortalities based on Cherry et al. (2002). We then determine the total annual mortality rate for these segments as a percent of their respective population estimates. For dependent-age bears (<2 years old), we determine the percent of human-caused mortality relative to size of the population segment but do not include estimates of unknown/unreported mortality. Mortality data in this data release represent the individual records documented by the Interagency Grizzly Bear Study Team on an annual basis....
Categories: Data;
Tags: Greater Yellowstone Ecosystem,
Greater Yellowstone Ecosystem,
Idaho,
Montana,
USGS Science Data Catalog (SDC),
Conclusions: Grizzly bear population fragmentation corresponded to the presence of settled mountain valleys and major highways. In these disturbed areas, the inter-area movements of female bears was affected more than for male bears. Without female connectivity, small subpopulations of grizzly bears are not viable over the long term. Thresholds/Learnings: Females grizzlies reduced their movement rates drastically when settlement increased to >20% of a given area. In highly settled areas (>50% settlement), both sexes demonstrated similar reductions in movement. Synopsis: Researchers studied the current state and potential causes of population fragmentation in grizzly bears over western Canada, the Greater Yellowstone...
Categories: Publication;
Types: Citation,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Alberta,
British Columbia,
Canadian Rockies,
Chilcotin Ranges and Fraser Plateau,
Clear Hills and Western Alberta Upland,
These data are preliminary or provisional and are subject to revision. They are being provided to meet the need for timely best science. The data have not received final approval by the U.S. Geological Survey (USGS) and are provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the data. The Interagency Grizzly Bear Study Team (IGBST) evaluates mortalities for population segments within the DMA by deriving estimates of total mortality for independent-age (2 years or older) females and independent-age males, including estimates of unknown/unreported mortalities based on Cherry et al. (2002). We then determine...
Categories: Data,
Data Release - In Progress;
Tags: Greater Yellowstone Ecosystem,
Greater Yellowstone Ecosystem,
Idaho,
Montana,
United States,
Some of the SNK rasters intentionally do not align or have the same extent. These rasters were not snapped to a common raster per the authors' discretion. Please review selected rasters prior to use. These varying alignments are a result of the use of differing source data sets and all products derived from them. We recommend that users snap or align rasters as best suits their own projects. - This dataset consists of raster distribution maps for terrestrial vertebrate species in Alaska. Individual species distribution maps were developed using the best available known occurrence points for each species and modeled using MaxEnt software and a series of environmental predictor variables. Output maps were clipped...
Grizzly bear (Ursus arctos) connectivity pathways delineate predicted movement routes for grizzly bears between federally designated recovery zones in and near western Montana. These raster data are the official data release for Sells et al. (2023), "Predicted connectivity pathways between grizzly bear ecosystems in Western Montana." In summary, we built on recent work by Sells et al. (2022, 2023) to simulate movements using integrated step selection functions (iSSFs) developed from GPS-collared grizzly bears (F = 46, M = 19) in the Northern Continental Divide Ecosystem (NCDE). We applied the iSSFs in a >300,000 km2 area including the NCDE, Cabinet–Yaak (CYE), Bitterroot (BE), and Greater Yellowstone (GYE) Ecosystems...
The grizzly bear distribution boundary delineates the estimated geographic extent of occupied range of the Yellowstone grizzly bear population for the period 2000-2014. The distribution boundary was generated to provide reliable estimations of grizzly bear occupancy throughout time and for use as a monitoring tool in grizzly bear management and conservation. The boundary was delineated by the Interagency Grizzly Bear Study Team (IGBST) using an interpolation method based on grizzly bear telemetry and GPS locations as well as verified observations and signs of grizzly bears inside the Greater Yellowstone ecosystem during 2000 to 2014.
Categories: Data;
Types: Citation,
Downloadable,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
Shapefile;
Tags: Greater Yellowstone Ecosystem,
Grizzly Bears,
Idaho,
Montana,
Ursus arctos,
Understanding evolutionary processes that drive population dynamics is critical in ecology. Measuring the performance-density relationship in long-lived mammalian species demands long-term data, limiting the ability to observe such mechanisms. We tested density-dependent (intrinsic) and density-independent (extrinsic) drivers of body composition of grizzly bears (Ursus arctos) in the Greater Yellowstone Ecosystem over two decades.
Categories: Data;
Tags: Greater Yellowstone Ecosystem,
Idaho,
Montana,
USGS Science Data Catalog (SDC),
United States,
Grizzly bear (Ursus arctos) habitat use maps delineate predicted habitat use for grizzly bears around federally designated recovery zones in and near western Montana. These raster data are the official data release for Sells et al. (2022), “Grizzly Bear Habitat Selection Across the Northern Continental Divide Ecosystem” and Sells et al. (2023), “Grizzly bear movement models predict habitat use for nearby populations.” In summary, to better understand habitat selection by grizzly bears, Sells et al. (2022) developed and validated individual-based integrated step-selection functions (iSSFs) for 65 grizzly bears monitored in the Northern Continental Divide Ecosystem (NCDE; including 19 males and 46 females). Step-selection...
This dataset contains detection histories of grizzly bears in areas of Grand Teton National Park that are open for elk harvest as part of the Elk Reduction Program. Sampling followed a robust design analysis with 6 primary sampling periods of 4 weekly secondary sampling periods each during 2014-2015. In both years, primary sampling periods were in July-August (no elk hunt), September-October (no elk hunt), and November-December (elk hunt). Detections were based on genetic sampling (hair samples from barbed-wire hair corrals, tree rubs or other structures, and elk carcasses). Detection histories were derived from a total of 274 grizzly bear hair samples of 31 individuals. Twenty-six unique individuals (4 F, 22 M)...
Conclusions: Seismic cutline proportion did not explain landscape use by grizzly bears, but secondary effects of cutlines on landscape structure did. Declining use was mainly associated with increasing proportions of closed forest, and increasing variation of inter-patch distances, while use was mainly increasing with increasing mean patch size. Thresholds/Learnings: Bears appear to use areas more when landscape patches tend to be larger, and mean patch size is generally reduced with additional seismic cutlines. Also, bears appear to use areas more when landscape patches are consistently spaced, and the spacing between landscape patches becomes more variable with additional seismic cutlines. Synopsis: This study...
Categories: Publication;
Types: Citation,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Binning,
GPS locations,
Generalized linear models (GLM),
Land use configuration,
Landscape configuration,
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