Polygamous Kittlitz’s plovers travel further over larger areas and interact with more individuals than the monogamous white-fronted plover. Movement patterns and social interactions influence gene flow and thus impact on speciation, although evidence from the field is limited. Here, we show that 2 Malagasy plover species exhibit different spatial behavior and social structure, consistent with existing genetic data. These results have implications for the genetic, social, and spatial processes by which new species are formed.