SPATIAL AND TEMPORAL DISTRIBUTION OF RAILS IN COLORADO

Despite the nearly world wide occurrence of the Rallidae, many species are poorly known and most published data are based on local studies. Regional and statewide studies have been limited; consequently, uniform data concerning the biology of rails over large areas are lacking. Previous published reports of rails in Colorado refer to occurrence (Bailey and Niedrach 1965, Lane and Holt 1975) and censuses in limited areas (Boeker 1954, Glahn 1974). In early 1975 we began to investigate occurrence, densities and migration of rails in relation to habitats in Colorado. Marshes, apparently suitable for rails, are restricted in size and distribution and occur between 1100 and 3200 m. Colorado marshes resemble those typical of the Great Plains and Intermountain West.