Survival and cause-specific mortality of adult female mottled ducks in east-central Florida

An understanding of survival and underlying causes of mortality is essential to the development of effective management strategies for the mottled duck (Anas fulvigula) in Florida. From radiotelemetry data we estimated season-specific survival rates for the entire annual cycle, cause-specific mortality rates, and annual survival rates. We also tested for variation in survival in relation to year and period of the annual cycle. Our results suggest a strong temporal influence on survival of adult female mottled ducks, both within and among years. We found variation among years in the influence of various mortality agents, with alligators (Alligator mississippiensis), raptors, mammals, and human hunters being the principal mortality factors. Our results also suggest a link between surface water conditions within the Upper St. Johns River Basin (USJRB) and surrounding areas and survival. Agencies managing water and wildlife should be aware of this relationship and consider potential detrimental effects to mottled duck survival.