The nesting requirements and reproductive biology of the California Black Rail (Laterallus jamaicensis coturniculus) are poorly known. The main reasons for this are that Black Rails inhabit dense marshes and their small size and secretive nature have made them difficult birds to study (Todd 1977). Additionally, inland breeding populations are sparsely distributed, relatively inaccessible, and declining (Snider 1969, Rosenberg et al. 1991, Evens et al. 1991). As a result, California and Arizona list the California Black Rail as threatened and endangered, respectively (California Department of Fish and Game 1988, Arizona Game and Fish Department 1988). Information on reproduction is essential to management and protection of this threatened subspecies.