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E *) <br />diversity of the wild flock and may be of assistance in evaluating potential inbreeding effects <br />in the future. <br />Radiotelemetry techniques were first tested on cross - fostered whooping cranes in the RMP <br />(Drewien and Bizeau 1981). Beginning in 1979, flightless young were captured and marked <br />with plastic legbands to which miniature radio transmitters (45 -60 g) were attached. Local <br />movements of the radio - tagged birds were monitored on summering and wintering areas and <br />several individuals were followed during their fall migration between Grays Lake NWR in <br />southeastern Idaho and Monte Vista NWR in south - central Colorado. No adverse effects <br />were noted from capturing, banding, and radio - tagging young whooping cranes (Drewien <br />and Bizeau 1981). <br />On the basis of these preliminary studies, a cooperative Service -CWS- National Audubon <br />Society radio tracking program was initiated for birds in the AWP to determine various <br />aspects of migration ecology, including habitat characteristics, behavior, and sources of <br />mortality. During each summer 1981 -1983, small solar - powered transmitters were placed <br />on several prefledged whooping cranes captured during the routine color - banding operation <br />in WBNP (Kuyt 1979 @, 1979.b, 1992). Data were obtained on three southbound and two <br />northbound migrations. Most information involved the individuals or family groups actually <br />being followed, but data were also accumulated on other migrating whooping cranes <br />encountered during the project. <br />The successful tracking project resulted in important information concerning migration <br />routes, migration timing, flight methods and speed, stop -over locations and staging areas, <br />habitat use, social behavior, activity budgets, predator /disturbance reactions, and sources of <br />mortality (Howe 1989, Kuyt 1992). Perhaps the most important result obtained from this <br />tracking project has been documenting mortalities on the breeding grounds (wolf predation) <br />(Kuyt at al. 1981), during migration (power line collisions), and on the wintering grounds <br />(predation and disease). Two of nine radio- marked whooping cranes died within the first 18 <br />months of life as a result of powerline collisions (Kuyt 1992). Similar valuable information <br />has been acquired on migration and behavior of whooping cranes in the RMP (Drewien and <br />Bizeau 1981, Asherin and Drewien 1987, Drewien 21 al. 1989). <br />Additional powerline construction, throughout the principal migration corridor, will <br />undoubtedly increase the potential for collision mortalities. Tests of line marking devices, <br />using sandhill cranes as surrogate research species, have identified techniques effective in <br />reducing collisions (Brown and Drewien 19948, 1994, Morkill and Anderson 1992). Lines <br />should be marked in areas frequently used by whooping cranes. New line corridors should <br />avoid wetlands or other crane use areas. <br />Migration Habitat Management And Research: Based on a preponderance of sightings along <br />the central Platte River in Nebraska during 1820 -1948, Allen (1952) believed that whooping <br />cranes made that area a major stopover, remaining in the area for some days. In 1978, the <br />U.S. Fish and Wildlife Service designated an 88 km portion of the Platte River in central <br />Nebraska as critical habitat. <br />As a result of reduced channel width, loss of adjacent wet meadows, and encroachment of <br />the channel by woody vegetation brought on by diversion and storage of water for irrigation <br />