Experimental harvest regulations reveal that water availability during spring, not harvest, affects change in a waterfowl population

Population change is regulated by vital rates that are influenced by environmental conditions, demographic stochasticity and increasingly, anthropogenic effects.  Habitat destruction and climate change threaten the future of many wildlife populations, and there are additional concerns regarding the effects of harvest rates on demographic components of harvested organisms. Further, many population managers strictly manage harvest of wild organisms to mediate population trends of these populations.  The goal of our study was to decouple harvest and environmental variability in a closely monitored population of wild ducks in North America, where we experimentally regulated harvest independently of environmental variation over a period of four years. We used nine years of capture-mark-recapture data to estimate breeding population size during the spring for a population of wood ducks in Nevada.  We then assessed the effect of one environmental variable and harvest pressure on annual changes...