Habitat use by migrant shorebirds in saline lakes of the Southern Great Plains

Shorebirds migrating through the Southern Great Plains of North America use saline lakes as stopovers to rest and replenish energy reserves. To understand how availability of invertebrates, salinity, freshwater springs, vegetation, and water influence the value of saline lakes as migration stopovers, we compared lakes used and not used by migrant shorebirds. Shorebirds used lakes that had freshwater springs, mudflats and standing water, sparse vegetation (≤1% cover), low to moderate salinities (x^- = 30.87 g/L), and mean invertebrate biomass of 0.79 g/m². Lakes that were not used were generally dry or had hypersaline water (x^- = 82.56 g/L), lacked flowing springs and vegetation, and had few or no invertebrates (x^- = 0.007 g/m²). Our results suggest that reduced spring flows and increased salinity negatively affect availability of shorebird habitats and aquatic invertebrates. We recommend preservation of the freshwater springs discharging in the saline lakes. Because the springs are discharged from the Ogallala aquifer, which is recharged through the playa wetlands, the entire complex of wetlands in the Great Plains and the Ogallala aquifer should be managed as an integral system.