Seasonal abundance is known to fluctuate in many reptile species, but comparative studies of proximal macrohabitats across seasons are rare. We surveyed for differences in abundance in a common lowland Central American forest anole, Anolis polylepis, across proximal forest and riparian habitats during the wet and dry seasons in southwest Costa Rica. We found that dry-season decreases in population abundance of A. polylepis in a forest habitat are mirrored by simultaneous increases in abundance in an adjacent riparian area. This result is compatible with seasonal movements between forest and riparian macrohabitats in A. polylepis. Likely causal factors for this macrohabitat shift include increased risk of desiccation and decreased prey abundance in the forest habitat during dry periods. We briefly discuss potential conservation implications of habitat shifts to suitable microhabitats on this tropical lizard.