Behavior of Migrant Shorebirds in Saline Lakes of the Southern Great Plains

Abstract

We recorded and compared diurnal and nocturnal time-activity budgets of American Avocet (Recurvirostra americana), Lesser Yellowlegs (Tringa flavipes), Least Sandpiper (Calidris minutilla), and Wilson’s Phalarope (Phalaropus tricolor) on 21 saline lakes in the Southern Great Plains, USA, during spring and summer/fall 2002 and 2003 to examine importance of saline lakes as migratory stopover sites. All four species spent most of their time feeding (47-70%) and resting (7-37%) by day and at night during spring and fall migrations. Little time was spent in other behaviors. Time budgets differed among species and between seasons, likely due to different energy needs. Time spent foraging varied seasonally between saline lakes and freshwater playas for American Avocets and Least Sandpipers, likely due to differences in vegetation cover and availability of prey between these wetland types. For most species, time spent foraging and resting differed between day and night. Therefore, extrapolating diurnal activity budgets to the entire 24-hour period and from one type of habitat to another within the same region is not recommended. Saline lakes are used by migrant shorebirds as stopover sites where they replenish lipid stores. Conservation efforts should focus on preserving these unique wetlands and the freshwater springs that discharge in them.