The cypress heads sometimes serve as alligator holes, where the big reptiles and other aquatic animals are able to survive dry periods. As you drive along the park road, stop and examine these tree islands through your binoculars; they are favored haunts of many of the park’s larger wading birds. Look for herons, egrets, wood storks, and white ibis, which visit these swampy habitats to feed on the abundant aquatic life. Bald eagles find the tops of the tallest cypresses advantageous perches from which to scan the marsh. And at night certain of the cypress heads are “buzzard roosts”—resting areas for gatherings of hundreds of turkey vultures. Bayhead [Illustration: Bayhead] ALLIGATOR FLAG COCOPLUM SWAMP HOLLY CABBAGE PALMETTO REDBAY SWEETBAY SAWGRASS WILLOW ORCHIDS AND BROMELIADS Many of the tree islands in the fresh-water glades are of the type called bayhead. Growing in depressions in the limestone or from beds of peat built up on the bedrock, these plant communities contain a variety of trees, including swamp holly, redbay, sweetbay, wax myrtle, and cocoplum. Some of them, on the fringes of the brackish zone, are marked by clumps of graceful paurotis palms growing at their edges. Like the hardwood hammocks in the pinelands, bayheads are prevented from taking over the entire glades ecosystem by the dry-season fires that sweep the region at irregular intervals. The fires do not always affect the bayheads. A moat, formed by the dissolving action of acids from decaying plant materials on the limestone, may surround the tree island, providing some protection from fire. Wildlife concentrates in these moats during the dry season. Birds congregate here to harvest the fish, snails, and other aquatic life—and occasionally themselves fall prey to lurking alligators. Willow Head Willows pioneer new territories and create an environment that enables other plants to gain a foothold. Their windblown seeds usually root in sunny land opened by fire and agriculture. Since these trees require a great quantity of water, the solution holes in the glades are favorable sites. Seedlings grow, leaves fall, and stems and twigs die and drop—contributing to the formation of peat. When this builds up close to or above the surface of the water, it provides a habitat for other trees such as sweet bay and cocoplum; with enough of these the willow head changes character and becomes a bayhead.