Response of a reptilian ecosystem engineer to large-scale dune construction: implications for coastal wildlife

Abstract

Climate change-induced sea-level rise is a major threat to coastal habitat worldwide. Current management aimed at reducing beach erosion often focuses on protecting human structures, and research on the impacts of management on wildlife is lacking. I evaluated how a reptilian ecosystem engineer, the Gopher Tortoise (Gopherus polyphemus), colonized humanconstructed dunes along coastal scrub at the Merritt Island National Wildlife Refuge in Central Florida. Over two years I surveyed tortoise populations along natural dunes and two constructed dunes (completed in 2012 and in 2014) and estimated tortoise density each summer and winter. My models indicate that tortoise density along the 2014 dune was similar to that of the natural dunes (means ranging from 0.9 to 9.66 tortoises per hectare), and density peaked at a mean of 36 tortoises per hectare along the 2012 constructed dune. Overall, Gopher Tortoises rapidly colonized constructed dunes, and dune construction may represent effective management to reduce habitat loss for this species.