Rocky Mountain Sandhill Crane over-winter survival and resource selection within the Middle Rio Grande River Valley, NM

The MRGV is the principal wintering area for RMP sandhill cranes in west central New Mexico, mainly from Albuquerque south to Bosque del Apache National Wildlife Refuge BdA. The valley has long been recognized as an important wintering area for cranes Central Flyway Plan. Most winter on BdA or New Mexico Game and Fish property Bernardo Wildlife Area. These two areas alone are the single most important wintering areas for RMP cranes Drewien and Bizeau 1974. Smaller numbers of RMP cranes winter in southwestern New Mexico, including the hatch and Uvas valley in Sierra and Dona Ana counties, the Deming Columbus area in Luna County, and the upper Gila River, near Cliff in Grant County Drewien et al. 1995 along with a small number in Sulphur Springs Valley in Cochise County, Arizona specifically the Wilcox Playa and surrounding area. Historically, about 10 percent of the population winters in Chihuahua and Durango, Mexico Drewien et al. 1996, Lopez Saut et al. 2011. The quality of winter habitat is important because of the high densities of wintering cranes that are dependent on limited resources. Throughout their wintering range agricultural practices are changing, acreage of corn and small grains are decreasing due to increased demand for water. Therefore it is crucial that we identify what current carrying resource selection is for wintering RMP cranes and how this impacts over-winter survival. The primary purpose of this study will be to determine the over winter survival and resource selection of the RMP in order to establish the geographic area within which conservation measures could be undertaken to protect and enhance this population of cranes.