W. R. Marion

Habitat Evaluation for the Cape Sable Sparrow in East Everglades

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...


Food Habits of Three Bird Species on Phosphatemine Settling Ponds and Natural Wetlands

Common moorhens (Gallinula chloropus), double-crested cormorants (Phalacrocorax auritus), and mottled ducks (Anas julvigula) were collected from phosphate-mine settling ponds and natural wetlands in north and central Florida between June and October 1981. Contents of esophagi, proventriculi, and stomachs were removed from 185 birds, identified, and measured by volumetric displacement. Aggregate percentages of food items in diets were compared between settling ponds and natural wetlands. Rank order of items in moorhen diets differed among the 2 habitats. Plant foods comprised at least 80%...