During a two-year period (1970-71),3,037 hatchling Wood Ducks (Aix Sponsa) were web tagged and another 2.049 adults and sub-adults leg banded in an effort to measure preflight mortality, nesting population growth, and to indicate migration habits of those produced on the Big Lake National Wildlife Refuge. All ducklings web tagged were taken from nest boxes located on the refuge and all ducks were captured within or in close proximity to the nesting sites. Recoveries of web tags indicate an average annual mortality of 60.5% among preflight young, for the two-year period. Band returns indicate a 72.3% return of nesting females to the refuge and an annual growth of 60.6% in the nesting population. Direct band and tag returns indicate a dispersal of Wood Ducks from the refuge to other areas of the country starting late in the summer. The dispersal includes an early movement of drakes primarily to the north, as far as Wisconsin, and involves both adults and young-of-the-year.