Ducks were inventoried monthly over a 2-year period in order to compare usage of management units in the Louisiana coastal marshes. Areas inventoried were brackish and fresh water impoundments, which were managed for ducks. and marsh pump-out units, managed for beef cattle. In addition, natural marshes nearby were sampled as a control. Water depth readings were taken monthly and vegetation was sampled annually to provide information on factors affecting duck usage. Greatest duck usage was in the fresh water impoundments. but usage of the brackish impoundments was very similar to that of the control areas. Marsh pump-outs received lowest duck usage, and birds were present only after heavy rainfall temporarily flooded the areas. The major factors affecting duck were the types of vegetation, water depth, and time of year.
