Migratory shorebirds have dynamic and shifting habitat associations under variable precipitation conditions in the Southern Great Plains

ABSTRACT As climate change alters habitat availability and quality for wildlife globally, understanding how different species respond to these changes will be critical for effective conservation. Migratory shorebirds may be especially vulnerable to climate change because of their strong dependence on a variety of weather-dependent wetlands throughout their annual cycles. However, shorebirds are also flexible in their habitat and foraging behaviors and may be able to overcome the effects of reduced wetland availability during severe weather events such as drought by increasing the intensity of their use of more permanent waterbodies (i.e., lakes and rivers). By leveraging 16 years of citizen science eBird data that cover a range of precipitation conditions, we evaluated habitat associations of 9 shorebird species that migrate through the U.S. Great Plains during spring migration. We found that, regardless of precipitation conditions, all species were more abundant in locations with greater percent area of lakes or higher densities of wetlands. However, for some species, the association between abundance or occurrence on eBird checklists and availability of different waterbody types varied depending on precipitation conditions. Specifically, abundance per checklist of Recurvirostra americana (American Avocet), Calidris bairdii (Baird’s Sandpiper), Tringa melanoleuca (Greater Yellowlegs), and Charadrius vociferus (Killdeer) was greater at lakes during drought years compared to years with above-average or average precipitation. Counts of most species decreased as the percent area of the river increased, but for Tringa melanoleuca, C. vociferus, and Calidris pusilla the number of individuals counted was higher in areas with extensive river habitat during drought years. Because climate change projections indicate wetland availability will become more variable, shorebird conservation plans should consider a variety of waterbody types, including lakes and rivers, to provide migration stopover options, even during severe drought conditions, for the diverse group of shorebirds that migrate through the Great Plains.