Avian Communities in Bayheads, Willowheads, and Sawgrass Marshes of the Central Everglades

We compared avian community composition, species richness, and total bird abundance among three vegetation types (bayheads, willowheads and marshes), and between a reduced-hydroperiod and relatively unimpacted landscape in the central Everglades during July-August, 1996. Our results showed that the collective Everglades bird community contained a substantial number of forest birds as well as marsh species. Red-winged Blackbirds (Agelaius phoeniceus), Common Yellowthroats (Geothlypis trichas), and White-eyed Vireos (Vireo griseus) accounted for 65% of total individual birds during the period of study. Wading birds accounted for a relatively small proportion of the total avian community. White-eyed Vireo was the most abundant bird species in bayheads and was closely associated with that habitat. Red-winged Blackbird and Common Yellowthroat were the most abundant species in both willowheads and marsh vegetation. We found no significant difference in bird abundance among vegetation types (P > 0.05) nor between landscapes (P > 0.05). We also found no difference in species richness between landscapes (P > 0.05). A significant (P = 0.02) interaction between vegetation and landscape indicated that species richness differed among vegetation types in the unimpacted landscape, but not in the reduced-hydroperiod landscape. In the unimpacted landscape we detected significantly more species in bayheads than the other two vegetation types (both tests, P ' 0.004). An ordination revealed that in the unimpacted landscape, bird communities were more specific to vegetation types than in the reduced- hydroperiod landscape. Our study demonstrates that two characteristics of a relatively unimpacted landscape in the central Everglades are higher avian species richness and a more distinct avian community in bayheads than in willowheads or marshes. The Everglades restoration process will promote the conservation of avian diversity by restoring the landscape matrix of both marsh and bayhead vegetation.