Distribution and frequency of occurrence of King and Clapper Rails in managed impoundments and tidal marshes

Abstract

Rails have been used as a bio-indicator of marsh health; however, little is known about rails' presence and distribution within the ACE Basin of South Carolina. We estimated frequency of occurrence of rails in managed impoundments and tidal marshes during summer 2005, and winter and summer 2006, using call broadcast surveys. We related occurrences to habitat structure during winter and summer 2006. One King and 3 Clapper Rails were radio-tracked from March to August 2006 to assess distribution during the breeding season. Rails occurred more frequently in tidal marshes during each season. Different habitat variables explained frequency of occurrence each season. All Clapper Rail radio-locations were in tidal marshes, but locations of the King Rail were in managed impoundments. Tidal marshes provided resources for Clapper Rails, while managed impoundments provided resources for King Rails. Further research is needed to improve management of impoundments to provide enhanced habitat for rails and their allies.