The Bates Hole/Shirely Basin IBA is located in both Natrona and Carbon counties, southeast of Casper, WY. Landowners include the Bates Creek Cattle Company (BCCC), Two-Bar Headquarters, and Garrett Ranch, however the majority of the land is federally owned and falls under the jurisdiction of the BLM.

Ornithological Summary

The Bates Hole/Shirely Basin IBA is important because it provides critical and large contiguous sagebrush habitat for sagebrush and obligate species. The Greater Sage-grouse populations and historic range is a fraction of what it once was. The sage-grouse have experienced dramatic declines over the last half of the 20th century and have been extripated in five states and one Canadian province, moreover, populations have declined 33% since 1985 over the remainder of it's range in the west (Connelly and Braun 1997). The declines have alarmed many in the conservation/wildlife management field, and has lead to a petition to the USFWS to become and endangered or threatened species. The predominant reason for the declines in abundance and distribution are permanent loss, degradation, and fragmentation of the shrub-steppe ecosystem, the habitat type found within the Bates Hole/Shirely Basin IBA site and therefore is of particular concern. The area is also part of the Greater Sage-grouse local conservation planning area designated by the Wyoming sage-grouse state conservation plan. The Bate Hole/Shirely Basin site will be one of the first areas (in the conservation plan) to address the problems and possible solutions for sage-grouse declines in the area. In addition to sage-grouse, the area also supports the host of other sagebrush obligate species such as Sage Thrasher, Brewer's Sparrow, Vesper Sparrow, Green-tailed Towhee, White-crowned Sparrow, and Savannah Sparrow.

Conservation Issues

Weed management is needed as well as sagebrush treatment to revive decadent stands. Wildlife and livestock use have the potential to damage riparian areas and vegetative communities. More work needs to be done in the way of determining, what level of use affects sage-grouse nesting habitat, wintering habitat, etc. Energy development and recreation can impact sage-grouse in the IBA. Habitat impacts can occur from off-road vehicle use. Energy development and various mining activities (gravel, bentonite, uranium) can negatively impact sage-grouse through habitat disturbance and habitat loss degradation.

Ownership

Federal, Private, and State (majority federally managed by the BLM)

Habitat

The area is primarily comprised of sagebrush shrubland with limited lowland riparian and agricultural habitats as well. The topography is relatively flat with some gently rolling hills. The vegetation of the area is dominated by stands of Wyoming Big Sagebrush, while black sagebrush and Wyoming three-tip occur on relatively flat terrain, basin big sagebrush can be found in drainages and mountain silver sagebrush occur in the riparian areas. Some plains silver sagebrush, black greasewood, and rabbitbrush also occur in the area. Dominant grasses include western wheatgrass, Idaho fescue, mutton bluegrass, needleandthread, sandberg bluewgrass, junegrass, and some cheatgrass. The common understory forbs include: buckwheats, curlycup gumweed, gilia, lupine, phlox, chickweed, hairy goldaster, bastard toadflax, dandelion, sandwort, milkvetch, Asteraceae species, and scarlet globemallow. There are some areas of irrigated haymeadows, which are used exclusively as summer habitat by Greater Sage-grouse within the area. Cattle and some sheep grazing occur on much of the area. On BCCC rotational cattle grazing management system has been employed since 1973. The MLLCC grazes cattle in the more traditional 3-pasture rotation and the Mills ranch graze both cattle and sheep using traditional, season-long grazing scheme.

Land Use

Cattle and some sheep grazing occur on much of the area. On BCCC rotational cattle grazing management system has been employed since 1973. The MLLCC grazes cattle in the more traditional 3-pasture rotation and the Mills ranch graze both cattle and sheep using traditional, season-long grazing scheme.

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