The Influence of Tide, Wind, and Habitat on the Abundance and Foraging Rate of Three Species of Imperiled Plovers in Southwest Florida, USA

SIMPLE SUMMARY: This research studied three species of imperiled shorebirds—Piping Plover, Snowy Plover, and Wilson’s Plover—that are similar in appearance and share habitats outside the breeding season. Researchers counted the number of these birds on a barrier island in Southwest Florida and examined how tide and wind affected their abundance and foraging behavior. They found that all three species were more likely to be found on the mudflats during lower tides and on the beach during higher tides. All of the feeding observed was on the mudflat, but one of the species, Wilson’s Plovers, was never observed feeding during the study. The high densities of these plover species are likely due to the mudflat habitat that provides more food, a beach habitat that provides a relatively safe location to roost, and the location of the barrier island, which is surrounded by other good places to forage and rest. While each species used the barrier island’s habitats slightly differently, the high densities of all three species present an opportunity to have a large conservation impact by protecting this dynamic area. ABSTRACT: Piping Plover (Charadrius melodus), Snowy Plover (Charadrius nivosus), and Wilson’s Plover (Charadrius wilsonia) are imperiled species that overlap in both their range and habitat outside the breeding season. The purpose of this research was to document the abundance of these species at a barrier island in Southwest Florida, USA, and to examine the influence of tide and wind on both their abundance and foraging. We walked ~700 m surveys through tidal mudflat and adjacent beach semiweekly at 0730–1030 from 24 September 2021–4 March 2022. During these 38 surveys, Piping Plovers were the most abundant of the three species, and the average number counted was 34 (SD 17.3) compared with 11 (SD 6.3) Snowy Plovers and 14 (SD 14.1) Wilson’s Plovers. All of the species were more likely to be found on the mudflats during low tides and the beach during high tides. Our findings suggest the high densities of Piping, Snowy, and Wilson’s Plover are due to a mudflat habitat that provides high availability of prey, a beach habitat that provides a relatively safe location to roost, and the context of the barrier island, which is surrounded by other suitable habitats. While each species used the barrier island’s habitats slightly differently, the high densities of all three species present an opportunity to have a large conservation impact by protecting this dynamic area.