Piping Plover (Charadrius melodus) Hatch a Least Tern (Sternula antillarum) Egg in a Mixed Clutch at Fire Island, NY

Abstract

During the summers of 2019-2022 on Fire Island, NY, we observed 3 instances of Charadrius melodus (Piping Plover) incubating Sternula antillarum (Least Tern) eggs within mixed clutches, including a nest where the incubating plovers hatched chicks of both species. While mixed clutches of plover-tern nests have been observed previously, this case appears to be one of the few documented instances of a shorebird (Order: Charadriiformes) hatching eggs of another species with different parental care requirements. Moreover, the mechanisms by which these mixed clutches occurred on Fire Island appear to differ from past observations. Previously, mixed plover-tern clutches involved nest usurpation, whereas our observations suggest egg dumping by terns. Future research should investigate the role of habitat limitation in shorebird nesting and offspring recognition.