Specific Comments on Platte River Draft EIS

Home Browse Search

tinued present population of whooping cranes in th Wood Buffalo-Aransas flock (approximately 85 birds as of January 1985) is equivalent to on y 0.02 percent of the sandhill cranes in the Platte River staging population, or a ratio of 3,918 s ndhill cranes for every whooping Crane. 2) Sandhill cranes stage along the Platte Rivf 30 days. Whooping cranes, in contrast, are n Instead, they select stopover sites on a nor periods (primarily overnight stays of about 1: the number of whooping cranes known to hav (1940-1984) represents less than 1 percent o the assertion is made that twice as many birds on a traditional basis, ranging for approximately t dependent on specific habitat along the flyway. •aditional basis and typically use than for short to 16 hours). Consistent with this strategy of use, stopped on the Platte River over the past 45 years the stopover opportunities (less than 2 percent if topped on the river as were sighted). 3) Whooping cranes depart on migration in a small groups usually consisting of 1 to 3 bir the stopover options available to migrant bir, too small to accommodate large flocks. As di sites commonly included small natural and rr some wetlands that were intermittent or epher a review of aerial photographs and topograp well distributed throughout the Nebraska por the flyway. 4) A more than a five-fold increasing the W, achieved since 1941, an unlikely accomplishn flyway was truly limiting the survival and rec( Rather, it appears apparent that the whooping ci different types of wetlands (including manmade species' survival advantage, providing resilier habitat. iggered fashion and proceed along the flyway in This pattern of migration effectively increases in that it facilitates the use of wetlands that are unented during radio-tracking surveys, stopover made water bodies of 5 acres or less, as well as ral (e.g., 1/4 acre flooded grain fields). Based on ; maps, such small-sized wetlands appear to be n of the migration corridor and elsewhere along Buffalo-Aransas population has been steadily if the availability of stopover habitat along the y of the species. 's opportunistic stopover use of a wide variety of P,rvoirs, farm ponds and stockponds) serves to the in adjusting to year-to-year changes in flyway Regulatory opinion that wetlands along the Platte iver provide food items necessary to the species' nutritional well-being and reproductive prepar dness is inconsistent with the fact that most whooping cranes do not use this habitat during se sonal migrations. As stated previously, of the 27 migration passes by individual birds monitored across Nebraska during the 1981-1984 radio- tracking surveys, no stopovers occurred along t e Platte River. Moreover, despite considerable survey analysis over the past 20 years (1965-198 ) the number of whooping cranes sighted on the Platte River (20 birds) represents only 1 percent f the potential stopovers; i.e., 99 percent of the whooping cranes that migrated across the Platte during these 20 years chose not to use habitat associated with the river (98 percent if it is assure that twice as many birds stopped on the river as were sighted). Nonetheless, the size of the Woo Buffalo-Aransas population doubled during this period. The contribution of food items consumed at lo annual nutritional requirements of individual ` (overnight) duration of most stopovers. If a spec accordance with the species' opportunistic strate at that site play no role at all in satisfying annual ons along the U.S. portion of the flyway to the oping cranes is obviously limited by the short stopover site is not used during a given year (in for selecting stopover habitat), then food sources :tarv needs. A