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Arthur Middleton

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Ungulates are key components in ecosystems and economically important for sport and subsistence harvest. Yet the relative importance of the effects of weather conditions, forage productivity, and carnivores on ungulates are not well understood. We examined changes in elk (Cervus canadensis) recruitment (indexed as age ratios) across 7 states and 3 ecotypes in the northwestern United States during 1989–2010, while considering the effects of predator richness, forage productivity, and precipitation. We found a broad‐scale, long‐term decrease in elk recruitment of 0.48 juveniles/100 adult females/year. Weather conditions (indexed as summer and winter precipitation) showed small, but measurable, influences on recruitment....
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Annual variation in winter severity and growing season vegetation dynamics appear to influence the demography of temperate herbivores but parsing winter from spring effects requires independent metrics of environmental conditions specific to each season. We tested for independence in annual variation amongst four common metrics used to describe winter severity and early growing season vegetation dynamics across the entire spatial distribution of elk (Cervus elaphus) in Wyoming from 1989 to 2006. Winter conditions and early growing season dynamics were correlated in a specific way. Winters with snow cover that ended early tended to be followed by early, but slow, rises in the normalized difference vegetation index...
Categories: Publication; Types: Citation; Tags: Landscape Ecology
This is the data archive for the publication Ungulate Migrations of the Western United States, Volume 1 (Kauffman et al. 2020) and includes the collection of GIS map files that are mapped and described in the report. These map files are meant to provide a common spatial representation of the mapped migrations. This data release provides the means for ungulate migrations to be mapped and planned for across a wide variety of landscapes where they occur. Due to data sharing constraints of participating agencies, not all the files that underlie the mapped migrations included in the report have been released. Data can be viewed at: https://westernmigrations.net. Data in this archive can be downloaded two ways. To download...
Elk within the Clarks Fork herd migrate though some of the most rugged and remote terrain in the lower 48 states. The herd, which numbers around 3,000, winters in the Sunlight Basin and the Absaroka foothills just west of Cody, WY. Winter ranges are a mix of sagebrush hills and lodgepole pine forests, within expansive private ranchlands. During migration, animals travel an average one-way distance of 33 miles, with some animals migrating as far as 67 miles. Spring migrations off of winter range head west towards Yellowstone National Park, up several drainages that flow out of the Absaroka Mountains, including the Clarks Fork of the Yellowstone, Crandall Creek, and smaller creeks to the south. Summer ranges consist...
The Cody elk herd migrates across rugged country on the eastern side of the Absaroka Mountains near Cody, WY. This large herd of 6,000-7,000 animals winters in foothill habitat to the south and west of Cody. There are three core winter areas, namely the valleys formed by the North and South Fork of the Shoshone River and the headwaters of the Greybull River north to Meeteetse creek. In spring, the elk that winter along the North Fork of the Shoshone generally follow the river west towards the park, some of them branching up Eagle Creek and other tributaries. The elk that winter in the South Fork of the Shoshone follow it upstream in spring, eventually heading west up Ishawooa Creek and into the Thorofare and Yellowstone...
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