BUFF-BREASTED SANDPIPER DENSITY AND NUMBERS DURING MIGRATORY STOPOVER IN THE RAINWATER BASIN, NEBRASKA

The Buff-breasted Sandpiper (Tryngites subruficollis) is a shorebird of conservation concern whose migration patterns and population size are poorly known. We conducted surveys in the Eastern Rainwater Basin, Nebraska, in 2004 and 2005 using distance sampling. This survey produced density estimates of 0.09 birds per ha in 2004 and 0.04 birds per ha in 2005. Because the study area was explicitly defined by soil characteristics, we were able to extrapolate from density estimates to produce predictions of overall numbers in the study area. We produced minimum estimates of the numbers of Buff-breasted Sandpipers stopping over in the region—43 300 in 2004 and 22 924 in 2005. When we restricted our predictions to only the area adjacent to roads, numbers of birds ranged from 13 488 to 41 513, depending on the area used. These predictions indicate two important findings—that 1) the current estimate of the world population of Buff-breasted Sandpipers of 15 000 to 20 000 individuals is too low, and 2) the Eastern Rainwater Basin appears to be a primary spring stopover site for the species in the North American Great Plains.