Threats to Wildlife and the Platte River

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p. 12 WILDLIFE The Rainwater Basin wetlands of Nebraska are located approximately 10 miles south of the Platte River, stretching from south of Lexington to east of Grand Island, covering an area roughly 100 miles by 30 miles. The basin wetlands serve as a spring staging area for millions of waterfowl. Although the Rainwater Basin is not hydrologically linked to the Platte River, the basin and the river are connected ecologically. Many of the same species that use the basin also use the Platte, especially when freezing makes the Rainwater Basin area unavailable in winter and occasionally in the early spring, forcing waterfowl to move to the Platte. Long an important habitat for waterfowl and increasingly used by Sandhill and Whooping cranes, the original area of wetlands in the Rainwater Basin has shrunk by 85 -90 percent, lost mainly to cropland conversion. This has caused so much crowding of species that continue to use the area that avian cholera outbreaks, first confirmed in Nebraska in 1975, are now common (USFWS 1981, p 87; NGPC 1985a, p 17; Currier et al. 1985, p 43; Farrar undated). In years when the basin is relatively dry, the birds are crowded into smaller and fewer wet areas and the cholera risk grows. Approximately 80,000 - 90,000 birds died from avian cholera in 1980 alone, shortly before the breeding season (USFWS data in Currier et al. 1985, p 43; Friend 1981 in Krapu et al. 1982). Between 1975 and 1987 an estimated total of 200,000 to 300,000 birds died during disease outbreaks in this area. Species Requirements Sandhill Cranes For Sandhill Cranes, the Big Bend area of the Platte is by far the most important spring staging area of all in the United States. A half - million Sandhill Cranes (80 percent of the currently stable world Sandhill Crane population) depend upon the river and associated wet meadows as a migratory staging area each spring before flying to breeding grounds in Canada, Alaska, and Siberia (USFWS 1981, pg i).2 The convergence of Sandhill Cranes on the Big Bend stretch of the Platte is the largest concentration of any species of crane anywhere in the world. In fact, there are more cranes on the Platte River in the spring than there are total cranes of all other species in the world combined (M. Gochfeld 1988, pers. comm.). 2 The Sandhill Crane population in this area predominantly consists of Lesser Sandhill Cranes, although a few Canadian and Greater Sandhill Cranes also use the area, intermingling with the Lesser subspecies.