Spatial, Temporal and Weather factors Influencing the Foraging Behavior of Migrating Semipalmated Sandpipers

Abstract

The role of spatial, temporal and weather factors on the foraging behavior of migrating Semipalmated Sandpipers (Calidris pusilla L.) was explored during fall staging in the upper Bay of Fundy (Canada) over two years. Factors that influence foraging benefits during migration stopover may influence fitness in a migratory species. The number of captures and success rate peaked during the middle of day regardless of temperature. Pecking rate decreased with increasing temperature while the number of captures and success rate increased suggesting that foraging benefits are lower at low temperatures. The number of captures and success rate did not change as a function of tide stage or time of year despite presumed changes in prey availability and/or density. Running and flying activities were also influenced by time of day and weather factors. Difficulties in locating prey or detecting predators may explain the effect of time of day and increased thermoregulation costs and changes in prey activity are probably involved in explaining how weather factors influence foraging behavior in this species