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Full-Text Articles in Life Sciences

Effects Of An Early Spring Burn On Greater Sandhill Crane Nesting Success At Malheur National Wildlife Refuge, Oregon, Carroll D. Littlefield, John E. Cornely, Bradley D. Ehlers Jan 2001

Effects Of An Early Spring Burn On Greater Sandhill Crane Nesting Success At Malheur National Wildlife Refuge, Oregon, Carroll D. Littlefield, John E. Cornely, Bradley D. Ehlers

Proceedings of the North American Crane Workshop

A 2430 ha prescribed burn was conducted on Malheur National Wildlife Refuge, Harney County, Oregon in March 1985. About 35 days later, 11 greater sandhill crane (Grus canadensis tabida) pairs nested within the burned area; 9 of these hatched. The remaining 2 clutches were destroyed by coyotes (Canis latrans). Crane hatching success was significantly higher (P = 0.01) on the burned area (81.8%) than elsewhere (38.5%). Two factors were likely responsible for the higher success rate in the burn; nests were placed in deeper water and the smaI1 mammal prey base was temporarily reduced or eliminated …


Models For The Adaptive Harvest Management Of Rocky Mountain Sandhill Cranes: Problems And Potential, William L. Kendall, Roderick C. Drewien Jan 2001

Models For The Adaptive Harvest Management Of Rocky Mountain Sandhill Cranes: Problems And Potential, William L. Kendall, Roderick C. Drewien

Proceedings of the North American Crane Workshop

The migratory Rocky Mountain Population (RMP) of the greater sandhill crane (Grus canadensis tabida) breeds primarily in river valleys, marshes, and meadows of western Montana and Wyoming, southeastern Idaho, northern Utah, and northwestern Colorado. The RMP winters primarily in the Middle Rio Grande Valley of New Mexico, with smaller concentrations in the southwestern parts of that state, southeastern Arizona, and the northern highlands of Mexico. The San Luis Valley of Colorado is used as a stopover in both the spring and fall migrations. The RMP has been hunted on a permit basis since 1981, and currently these cranes …


Nesting Ecology Of Sandhill Cranes At Grays Lake, Idaho, Jane E. Austin, L. J. Ball, Adonia R. Henry Jan 2001

Nesting Ecology Of Sandhill Cranes At Grays Lake, Idaho, Jane E. Austin, L. J. Ball, Adonia R. Henry

Proceedings of the North American Crane Workshop

We examined the nesting ecology of greater sandhill cranes (Grus canadensis tabida) at Grays Lake, Idaho during 1997-99 to detennine the effects of nest-site characteristics and land use on crane nest success. These are preliminary results from 3 years of a 4-year study. Crane nests were located in portions of the Grays Lake basin from early May through late June each year (n = 131 in 1997; n = 131 in 1998; n = 143 in 1999). Apparent nest success varied among years (54% in 1997, 71% in 1998, and 53% in 1999; overall average of 59%). We …


The Importance Of Early Successional Habitats To Rare, Restricted-Range, And Endangered Birds In The Ecuadorian Andes, Mark R. Welford Jan 2001

The Importance Of Early Successional Habitats To Rare, Restricted-Range, And Endangered Birds In The Ecuadorian Andes, Mark R. Welford

School of Earth, Environment, and Sustainability Faculty Publications

Since the mid-1980s, exhausted pastures in Ecuador have been increasingly abandoned, allowing forest regeneration. At approximately 2,200 m in the Tandayapa valley I surveyed four abandoned pastures to evaluate their use by birds. Each former pasture represented a different age of vegetation maturity. The number of bird species recorded in each successively older abandoned pasture increased but only half the number of species recorded in the undisturbed forest site was recorded in the most mature pasture. However, at least four restricted-range bird species were recorded in a single pasture. As pastures rapidly convert to secondary forest, more bird species and …