Priorities for Future Research

Research needs for the habitat and harvest management of the Clapper Rail have been summarized by Eddleman and Conway (1994). They include research on methods for assessing relative abundance, distribution, and population trends using tape playback or call counts; additional banding programs to determine survival rates, local population sizes, and migration patterns; additional research on habitat manipulations and the effects of habitat management practices; the development of methods to assess harvest; and investigations of basic biology, with emphasis on variation in population parameters, calling behavior (using consistent terminology for the various vocalizations), external age and sex determination, postbreeding biology, and winter biology.

Information on distribution, especially outside the United States, is needed, as well as clarification of the taxonomic status of several subspecies. Additional material is needed to determine the validity of several subspecies from the Caribbean and adjacent mainland areas that are described from < 10 specimens. Several taxonomic questions might be answered by detailed study of molts and plumages using captives or conducted in conjunction with intensive trapping and marking of a local population. The nature of geographic variation in measurements and plumage is poorly known and needs clarification (Kale 1978). At least one researcher has questioned the validity of all subspecies in the eastern United States (Heard 1983). Most study of Clapper Rails in the Americas since 1980 has focused on endangered western taxa (obsoletus, levipes, yumanensis) or on populations on the northern Atlantic Coast; additional work is needed on all aspects of the biology of birds in other portions of the geographic range, especially those found mainly in mangrove habitats (Kale 1978, Owre 1978). Contaminants accumulate in most habitats used by Clapper Rails (Eddleman et al. 1988); additional study of the effects of these potential toxins on reproduction and mortality is essential to conservation programs for this species.