The Ecology of Hydric Hammocks - USGS National Wetlands ...

no specific habitat preference; it hasbeen reported i n coastal hammock(Pearson 1951) and hydri c hammock(Layne 1970). The panther probablywas characteristic of hydric hammockbefore the elimination of most breedingpopulations from northern Floridaby man. Like the panther, the Floridabl ack bear (Ursus f loridanusf loridanus) has no specific habitatpreference. Instead, the preferredhabitat of bears is a mosaic of wetlandand upland forests (Harlow 1961),including hydric hammocks. Bears arestill relatively common in and nearthe Ocala and Osceola NationalForests, which incl ude some hydrichammock habitat. Specific bear sighting~were reported for the Ocala NationalForest by Florida Game andFresh Water Fish Commission (1976) andfor the Osceol a National Forest (U.S.Fish and Wild1 ife Service 1978). Thesoutheastern brown bat (Plyotis austroriparius)and bobcat (iynx rufus)also occur in hydric hammocks (Pearson1954).4.4.2 Sel ccted SoeciesArmadillos have been studied extensivelyin Florida, though not withreference to specific habitats. Thediet of armadillos in Florida (Nesbittet al. 1977) consists mostly of insects(78% by volume) and includessmall quantities of earthworms (5%),reptiles and amphibians (1% andbirds and mammals (~1%). Though a varietyof vertebrates are included inthe diet, these account for ~0.01% ofthe items eaten (Wirtz et a]. 1985).Presumably an abundance of macroinvertebratesin the leaf 1 itter of hydrichammock is responsible for the abundanceof armadillos there, Armadillosdig burrows and den underground; inregularly flooded areas, burrows areplaced in patches of high ground.Gray squirrels occur at densities ofroughly 5 per ha in inland hydric hammockand 2.5 per ha in coastal hydrichammock in autumn (Jennings 1951).Staple foods of the gray squirrel inhydric hammock and adjacent forestsare the seeds of loblolly pine and theSeeds, buds, and flowers of hickories,Oaks, elms, magno1 ias, and red maples.The abcndzRcp r _ r ~ st2yl~ fnod' chiftsseasonal 1 y among 1 ~cal pl ant communi -ties, affecting the local distributionof sauirrel s. From september to mid-~anua'r~, acbrns' 'and hickory nuts areavailable in all habitats, squirrelsare widely distributed, and they becomefat. By mid-January the supplysf hard mast is exhausted, but budsand seeds of elm and maple b ~ ~ ~ m eabundant in hydri c hammock and riverswanp, and sqg;~yclr {perhepr the entire population) become concentratedin these communities, with a densityof 13.8 per ha recorded by Jennings.At thi s time squirrel s abandon coastalhydric hammock, because cedar berriesare no longer avail able; 1 ittle foodis produced and no squirrels are presentthere until autumn. In springand summer, squirrel s are dispersedthroughout river swamp, hydric hammock,and nresic hammock. Green nutsof hickories, oaks, and loblolly pinesare eaten in July and August. Usuallya gray squirrel can find at least twoof these plant communities by movingonly a few hundred feet, because manyhydric hammocks are small and ecotonalor, if large, are interspersed withdendri tic swamps and mesic ridges.Squirrels scatterhoard acorns in thesoil, especi a1 ly at elevated sitesnear the bases of trees and stumps.Acorns buried during drought periodsmay be covered subsequently by standingwater before they are consumed.The supply of stored food helps supportthe squirrel population throughthe winter and may be an essential resourcefor the spring breeding season.While lack of an acorn crop in one ora few species of oak is normal, a completefailure of acorn mast in allspecies is uncommon. In such a mastfailure, the few available acorns werecompletely harvested by wild1 ife bymid-October; thereafter the squirrelssurvived by recovering stored acorns(Jennings 1951). Gray squirrels nestin tree cavities (usually in liveoaks) during winter, and in the springthey build nests made of leaves andtwigs or of cabbage palm fibers. Ordinarilya SPrlng and a fall breedingseason Occur, but spring breeding does