Tens of thousands of shorebirds use saline lakes as migratory stopovers in the Southern Great Plains, USA. To assess their foraging strategies and understand how they replenish energy reserves during spring and summer/fall migrations, we examined diets, prey taxa selection, and prey size selection of American Avocets (Recurvirostra americana), Least Sandpipers (Calidris minutilla), Wilson's Phalaropes (Phalaropus tricolor), and Lesser Yellowlegs (Tringa flavipes). Migrant shorebirds foraged opportunistically by taking most prey taxa according to their availability. Least Sandpipers preferred small prey (2–5 mm), whereas American Avocet, Wilson's Phalaropes, and Lesser Yellowlegs generally preferred intermediate and large prey (6–20 mm). By consuming prey taxa according to their availability and prey sizes that require minimum energy to capture and ingest, shorebirds increase their ability to replenish energy reserves while migrating through interior North America. Drought and drying of freshwater springs will reduce availability of prey in saline lakes for migrating shorebirds. To preserve the saline lakes as important habitats where shorebirds replenish nutrient reserves while migrating through the Great Plains, it is important to conserve groundwater so that freshwater springs continue to discharge into the lakes.