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

no specific habitat preference; it hasbeen reported in coastal hammock(Pearson 1951) and hyaric nammoc~(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 1 oridanusf 7oridanus) 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 include some hydrichammock habitat. Specific bear sighting~were reported for the Ocala NationalForest by Florida Game andFresh Water Fish Commission (1976) andfor the Osceola National Forest (U.S.Fish and Wildlife Service 1978). Thesoutheastern brown bat (Myotis austroriparius)and bobcat (Lynx rufus)also occur in hydric hammocks (Pearson1954) .4.4.2 Selected 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 a7. 1985).Presumably an abundance of macroinvertebratesin the leaf 1 itter of hydrichammock is responsible for the abundanceof armadi 11 os there. Armadi 110sdig burrows and den underground; inregul arly fl ooded 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 lobfolly pine and theseeds, buds, and flowers of hickories,oaks, elms, magnolias, and red maples.TL,,,, - abundanc~ 3f rtz:!e fnndc chiftsseasonally among 1 ocal plant communi -ties, affecting the local distributionof squirrels. From September to mid-January, acorns and hickory nuts areavailable in all habitats, squirrelsare widely distributed, and they becomefat. By mid-January the supplyof hard mast is exhausted, but budsand seeds of elm and maple becomeabundant in hydric hammock and riverswamp, and squirrels (perbap: the entirepopulation) become concentratedin these communities, with a densityof 13.8 per ha recorded by Jennings.At this time squirrels abandon coastalhydri c hammock, because cedar berriesare no longer available; little foodis produced and no squirrels are presentthere until autumn. In springand summer, squirrel s are dispersedthroughout river swamp, hydri c hammock,and mesic 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.Squirrel s 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 popul ation throughthe winter and may be an essential resourcefor the spring breeding season.While 1 ack 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 werecompl etely harvested by wi ldl ife bymid-October; thereafter the squirrelssurvived by recovering stored acorns(Jennings 1951). Gray squirrel s nestin tree cavities (usually in liveoaks) during winter, and in the springthey build nests made of leaves andtwigs or of cabbage palm fibers. Ordinarilya spring and a fall breedingseason occur, but spring breeding does