Local and Landscape Analyses of Habitat Selection of South Carolina Clapper Rails (Rallus crepitans)

The Clapper Rail (Rallus crepitans) is an avian marsh specialist that depends exclusively on coastal wetlands for all aspects of its life cycle, and is valued for its role as an indicator of ecosystem health. This study used radio telemetry in the Ashepoo-Combahee-Edisto Basin in South Carolina, USA, to assess Clapper Rail habitat selection in response to local and landscape variables and to investigate possible demographic consequences of differences in habitat selection. Compared to simulated home ranges, observed Clapper Rail home ranges during the breeding season contained greater amounts of potential forage area and shorter distances to potential forage locations at both local and landscape scales. Mean (± SE) Clapper Rail home range size was 1.06 ha ± 0.19. There were no significant differences between males (1.05 ha ± 0.26) and females (1.08 ha ± 0.25) in home range size. Home range selection based on optimization of potential forage resources may have demographic consequences for Clapper Rails; however, this hypothesis was only weakly supported. Clapper Rails foraging near exposed edges may increase mortality risk through predation, but this behavior may be negligible to survival provided that sufficient nearby cover exists. Resource abundance near cover is likely a major driver of habitat selection and is influencing Clapper Rail habitat selection at multiple scales, which may have consequences for adult survival.