NESTING SUCCESS AND SURVIVAL OF VIRGINIA RAILS AND SORAS

Lack of estimates of nesting success and annual survival of North Amer ican rails limits our ability to monitor rail populations, regulate ha rvest levels, and institute recovery programs. We here present Virgini a Rail (Rallus limicola) and Sera (Porzana carolina) population trends from Breeding Bird Surveys (BBS) throughout North America, estimates of nesting success from the Cornell Laboratory of Ornithology's Nest R ecord Program, and estimates of survival from radio-marked and banded birds in Arizona, 1985-1987. Virginia Rail populations declined 2.2% a nnually from 1982-1991, and Sera populations declined 3.3% annually fr om 1966-1991. Annual survival probability of radio-marked and banded V irginia Rails in Arizona was 0.526 +/- 0.195 and 0.532 +/- 0.128, resp ectively. Non-breeding survival probability did not differ between rad io-marked Virginia Rails (0.545 +/- 0.191) and Soras (0.308 +/- 0.256) in Arizona. All documented mortality occurred between October and Mar ch for both Virginia Rails and Soras. Virginia Rail and Sera nesting s uccess was 53%. Despite reproductive success and survival rates adequa te for population maintenance, rail populations appear to have decline d proportionately with continental wetland loss.