Phenology of southward shorebird migration through the Popayán Plateau, Andes of Colombia

Non-coastal shorebird flyways in the Neotropics are poorly understood. Museum skins, anecdotal hunter data and a preliminary survey in the early 1990s suggest that the Cauca River valley in the vicinity of Popayán, Colombia, might be an important shorebird migration stopover. To estimate current shorebird abundance and assess habitat use and threats during southward migration, we conducted weekly censuses from September to mid-December 2007 in two seasonally-flooded grasslands in the city of Popayán. We gathered complementary information on arrival dates through opportunistic records of vocal activity. Eight shorebird species were recorded, with Upland Sandpiper accounting for 60% of records. Upland, Buff-breasted, Pectoral and Baird’s Sandpipers were recorded as transients during September and early October. Lesser Yellowlegs and Solitary Sandpiper arrived later in October and remained through November; Spotted Sandpiper was present throughout the entire period. Later-than-usual rainfall during October caused changes in the availability of small water bodies and wet grassland. This could have led to a decrease in the number of shorebirds using the Plateau. Human disturbance is a threat to shorebirds and urban encroachment could be a future threat to shorebird habitats. As a natural barrier, the Popayán Plateau is a likely stopover for shorebirds migrating across the Andes during south migration. Searches for additional suitable sites, estimates of numbers of shorebirds using the Plateau, especially the near-threatened Buff-breasted Sandpiper, and cooperative work between local land owners and conservation agencies are priorities for the preservation of shorebird habitats in Popayán.