CHANGES IN SHOREBIRD AND EIDER ABUNDANCE IN THE RASMUSSEN LOWLANDS, NWT

Historical records of population numbers are almost entirely lacking f or shorebirds and some species of waterfowl breeding in the Nearctic. In 1975 and 1976, ground surveys of breeding birds were undertaken in the Rasmussen Lowlands, Northwest Territories. We carried out similar censuses in the same area during the summers of 1994 and 1995. Weather conditions and methods were very similar during the two sets of surve ys. For all years, we compared densities in different habitat types, a s well as estimates for the entire region of total numbers of breeding Red Phalaropes (Phalaropus fulicaria), Pectoral Sandpipers, (Calidris melanotos), White-rumped Sandpipers (C. fuscicollis), Semipalmated Sa ndpipers (C. pusilla), Black-bellied Plovers (Pluvialis squatarola), A merican Golden-Plovers (Pluvialis dominica), Dunlin (C. alpina), Baird 's Sandpipers (C. bairdii), and King Elders (Somateria spectabilis). W e found that breeding populations of Red Phalaropes, Black-bellied Plo vers, American Golden-Plovers, and King Elders in the 1990s had decrea sed substantially (76-87%) from their numbers in the 1970s. Numbers of other shorebird species did not decrease significantly (17-48%). Numb ers of Black-bellied Plovers have apparently decreased at staging site s on the east coast of the United States and Canada. However, for Amer ican Golden-Plovers, there is no evidence of a decline on the east coa st or in at least one other area in the eastern Nearctic. No other pop ulation information exists for Red Phalaropes breeding in the eastern Nearctic, Elder numbers appear to be decreasing throughout the Arctic. Possible reasons for declines are habitat changes in migratory stagin g sites and southern wintering areas. We need more consistent monitori ng of arctic shorebirds in order to identify species with continual po pulation declines. Further studies should emphasize Nearctic populatio ns of species showing substantial declines in this study, examining co nsistency of decreases throughout the Nearctic, and reasons for such c hanges.