Species Recovery Objectives for Four Target Species in the Central and Lower Platte River

Home Browse Search

resulted in habitat loss for whooping cranes. The Platte River from Lexington to Denman was designated as critical habitat for whooping cranes on May 15, 1978. Although this report is not being done under the Platte River Cooperative Agreement, whooping crane experts considered proposed habitat protection scenarios in relation to habitat needs for migratory whooping cranes in the AWP that stop over on the Platte River. The location of suitable whooping crane habitat may be more important than the amount of habitat. From a spacial distribution standpoint, suitable habitat in each of the 10 bridge segments seems sufficient if it were available. The approximately 2900 -acre habitat complex per each of 10 bridge segments (such as that described in the Platte River Management Joint Study and referenced in the Cooperative Agreement) is preferred over smaller units. However, smaller units may still be beneficial to whooping cranes if they contain suitable whooping crane habitat and are sufficient in number and spacing to be detectable to cranes flying over the Platte River. These habitat complexes should not be a substitute for maintaining the ecological integrity of the Platte River system. Existing suitable habitat should remain along the central Platte River exclusive of future restored and managed habitat. The migration pathway of whooping cranes through Nebraska is approximately 150 miles wide, with a north -south orientation, approximately 15 degrees west of "true" north. The 150 -mile corridor along the Platte River extends from roughly North Platte to Grand Island, although the "central" Platte River covers only 80 miles at the eastern end of the 150 -mile corridor. About 83 percent of the sightings in Nebraska occurred within the 150 -mile corridor, with the remaining (17 percent) occurring west of that corridor. In the 80 -mile migration corridor from Lexington to Grand Island, 74 percent of the confirmed statewide sightings from 1942 -2001 occurred. Since whooping cranes pass over the upper Platte River, provisions for their stopover needs should not be excluded west of the central Platte River (North Platte to Lexington). However, the feasibility of habitat development and management in this area is questionable. If it is determined at a future time that some habitat development and management is feasible in the upper Platte River area, a 90:10 split in terms of the proportion of whooping crane use or stopovers could be selected as a revised objective at that time. That is, management could occur for 90 percent of whooping crane stopovers on the central Platte River and for 10 percent of stopovers west of the central Platte River. The rationale for the 90:10 split is that if 10 habitat complexes are developed along bridge segments from Lexington to Chapman, as currently proposed, and if at least one habitat development occurred west of the central Platte River, then roughly 90 percent of new recovered suitable habitat would be available in the central Platte River and 10 percent would be available west of the central Platte River. This report stresses that existing suitable habitat should remain on the central Platte River exclusive of future restored and managed habitat. V