Bobby W. Brown

The Big Lake Wood Duck: A Two-Year Study Of Its Pre-Flight Mortality, Nesting Population Growth And Migration, 1970-71

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...

Year
1972

Refinement Of A Method For Calculating Wood Duck Survival

Web-tagging and banding returns from Wood Ducks (Aix ~ponsa) returning to their natal area after their first migration indicated that four times as many females returned as males. The proportion of returning ducks that had been banded as well as web-tagged was, however, the same for males and females. Most researchers who investigate pre-flight survival of Wood Ducks, utilize the technique of marking nestlings and recovering them after they reach flight stage. The proced ures outlined by Grice and Rogers (1965) are most often followed. In this method, a portion of the ducks that had been...

Year
1972

A Boat-Mounted Ladder-Stand For Inspecting Duck Nest Boxes

A boat-mounted ladder-stand was constructed to facilitate inspection of duck nest boxes that were mounted on poles between six and eight feet above water. This device allowed a large number of boxes to be inspected in a short period of time without having to set up and take down a ladder at each box. The ladderstand was constructed from materials readily available. The need to inspect nest boxes, which must be mounted high over water to protect them from floods, often involves a considerable amount of effort. A boat is usually used to transport an extension ladder to each box; the ladder...

Year
1972