Population Trends in Semipalmated Sandpipers from Migration Counts

Although Semipalmated Sandpipers are one of the most common shorebirds in North America, analyses of migration trends using data from the Maritimes, International and Ontario Shorebird Surveys, as well as the Quebec Checklist, collected between 1974–1998, consistently showed negative trends. An additional eleven years of data was assessed to determine if declines were ongoing. Analysis (Pearson correlation) of the Quebec Checklist data indicated a significant decline overall, from 1976 to 2008, and the percentage of checklists reporting flocks of >1,000 birds has decreased significantly since the 1970s. New analyses of population trends with migration monitoring data from eastern and central North America were conducted for the 35-year period from 1974 to 2009, using program ESTEQNINDEXE. Trends, although generally negative, were not statistically significant. In the North Atlantic region, where survey sites had the highest counts of Semipalmated Sandpipers, average abundance indices showed a pronounced decrease between 1985 and 1999 and an increase since then. Although the trend was not statistically significant, declines in Ontario amounted to an estimated 8% per year from 1974 to 2009. Counts were variable for Semipalmated Sandpipers in the Midcontinent region, although average abundance indices appeared lower in the second half of the analysis period (1989–2009). Thus, the population status of Semipalmated Sandpipers in North America may have improved since the 1990s, at least in the east.