Impaired Predator Evasion in the Life History of Birds: Behavioral and Physiological Adaptations to Reduced Flight Ability -- Dietary Calcium Availability and Reproduction in Birds -- Seasonal Metabolic Variation in Birds: Functional and Mechanistic Correlates -- Assessing Cause-Effect Relationships in Environmental Accidents: Harlequin Ducks and the Exxon Valdez Oil Spill. Current Ornithology publishes authoritative, up-to-date, scholarly reviews of topics selected from the full range of current research in avian biology. Topics cover the spectrum from the molecular level of organization to population biology and community ecology. The series seeks especially to review (1) fields in which an abundant recent literature will benefit from synthesis and organization, or (2) newly emerging fields that are gaining recognition as the result of recent discoveries or shifts in perspective, or (3) fields in which students of vertebrates may benefit from comparisons of birds with other classes. All chapters are invited, and authors are chosen for their leadership in the subjects under review. Current Ornithology Volume 17 1. Impaired predator evasion in the life-history of birds: behavioral and physiological adaptations to reduced flight ability - J. Lind, S. Jakobsson and C. Kullberg 2. Dietary Calcium Availability and Reproduction in Birds- S. J. Reynolds and C. Perrins 3. Seasonal Metabolic Variation in Birds: Functional and Mechanistic Correlates- D. L. Swanson 4. Assessing Cause-Effect Relationships in Environmental Accidents: Harlequin Ducks and the Exxon Valdez Oil Spill- J. A. Wiens, R. H. Day, S. M. Murphy, and M. A. Fraker