Managed Habitats Increase Occupancy of Black Rails (Laterallus jamaicensis) and May Buffer Impacts from Sea Level Rise

Abstract

Global wetland degradation and loss are occurring at a rapid rate, and in the United States over 50 % of wetlands in the lower 48 states have been altered since European settlement. In some cases, wetlands that were historically transformed for agriculture are now managed as wetland habitat. We conducted occupancy surveys for black rails (Laterallus jamaicensis) in managed and unmanaged areas of coastal South Carolina. We modeled landscape and local variables potentially influencing black rail occupancy and we assessed whether these habitat associations indicated vulnerability following expected alterations from sea level rise. Black rails occupied 17 of 344 surveyed sites. Landscape factors had the strongest influence on black rail occupancy. Occupancy was associated with impounded marshes, decreasing distance to forest, and greater proportion of marsh landscape within a 200 m buffer. We mapped parameters from our top model to predict the amount of current and future suitable habitat under various sea level rise scenarios at Bear Island Wildlife Management Area, a black rail hotspot. Suitable habitat decreases in tidal marshes but increases in impounded areas. The current use of impoundments by black rails could represent a new management strategy for mitigating the loss of black rail habitat.