In a study of the distribution of the Cape Sable sparrow (Ammodramus maritima mirabilis) in East Everglades, data were collected describing vegetation and soil characteristics at points sampled for occurrence of the sparrow. Data were used to assess the utility of a habitat suitability model. Of 13 variables derived from the soil and vegetation data, none were correlated with numbers of sparrows at the sample points. A biologist>s independent valuation of habitat suitability, at a subset of the points, was correlated with presence or absence of sparrows, and histograms representing frequency of occurrence suggested relationships between several vegetation variables and presence or absence. Presence-or-absence data may be more valuable than density for appraising habitat suitability for species, such as the Cape Sable sparrow, that have a territorial breeding season, limited reproductive capacities, and specific habitat requirements.
