A method is described that provides a rapid and accurate analysis of habitat used by radio-equipped animals. The digitizer (basically an X-Y plotter in reverse) converts maps into digital form by describing each habitat unit as a polygon that closely approximates the actual shape of the unit. The coordinates of each polygon are then stored on magnetic tape. Habitat classification data and other information are coded and combined with the proper polygon coordinates. This results in one file containing all habitat data. A computer program with inputs of tracking data and habitat data provides a listing of the habitat used by the animals studied. Analysis of habitat used by radio-equipped ducks is demonstrated using this method.