Area-occupied survey technique for nesting woodland raptors
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Book chapter↗
Geology topics
G.C. Iverson
Publications and source records attributed to G.C. Iverson.
Fat deposition and usage by arctic-nesting sandhill cranes during spring
Body weight, fat, and protein levels of arctic-nesting Sandhill Cranes ( Grus canadensis ) were measured at several locations during spring migration and on the breeding grounds. Body weights of adult males and females increased by about 34% (1,129 g) and 30% (953 g) from early March at the Platte River to late April at Last Mountain Lake, Saskatchewan; average fat content increased from about 250 to 990 g. Rates of weight gain and fat deposition among males and females averaged 25-18 and 16-13 g/day. Body weights and fat content of cranes staging along the North Platte River followed similar patterns and usually were higher than along the Platte River during comparable periods. Fat reserves of paired cranes collected after their arrival at a major breeding ground on the Yukon-Kuskokwim Delta in western Alaska averaged about 530 g, or about 46% less than peak fat content in Saskatchewan. Patterns of weight increase and fat deposition in cranes during migration were similar to those previously described for northern-nesting geese, except that nutrient storage is not sex specific in cranes. Body protein of adult female cranes did not change significantly during spring migration (P = 0.28). Female cranes allocate less nutrients to clutch formation in proportion to body size than do northern-nesting geese.
The Auk↗
Disseminated visceral coccidiosis in sandhill cranes
Disseminated visceral coccidiosis (DVC) caused by Eimeria spp was first recognized as a disease entity in captive sandhill cranes (Grus canadensis) and whooping cranes (G americana) at the Patuxent Wildlife Research Center. Because cranes produced at the Center are reintroduced to the wild to augment wild populations, studies involving both experimentally induced and natural infections were initiated to determine the potential or actual occurrence of DVC in wild Gruidae. Nine sandhill cranes dosed orally with eimerian oocysts of wild origin developed lesions characteristic of DVC. Extraintestinal granulomas associated with developing schizonts were found in 6 birds. Similar lesions were observed in wild sandhill cranes throughout parts of midwestern United States, Alaska, and Saskatchewan. These studies revealed the wide geographic distribution and the high frequency of occurrence of DVC in wild cranes.
Journal of the American Veterinary Medical Associa↗