What are the sources of uncertainty in black duck ecology that cause disagreement about appropriate hunting regulations?
Although evidence exists that harvest has contributed to overall mortality of black ducks, at present the role of hunting in the decline of the Black Duck population is unclear. The other major factors under consideration include impacts of mallard range expansion, and declines in the availability of breeding and wintering habitats. These factors have been summarized by several competing hypotheses that explain changes in reproduction and survival rates in terms of combinations of these factors.
