Mastodons (mammut americanum) diet foraging patterns based on analysis of dung deposits

Abstract

Wet sites in Florida are widely known for their exceptional preservation of organic materials, including diverse plant remains, collagen-rich bone, and brain and other animal soft tissues (Cushing, 1897; Clausen et al., 1979; Beriault et al., 1981; Wharton et al., 1981; Purdy, 1987a,b; Doran and Dickel, 1988; Dunbar et al., 1989; Doran, 2002; see Purdy, 1991). An extensive record of late Pleistocene and early Holocene biota is preserved in the wet sinkhole deposits submerged below the modern channel of the Aucilla River in northern Florida at the Page-Ladson site (8JE581). During the late Pleistocene, when water levels were lower and the local climate more arid (Brown and Cohen, 1985; Watts and Hansen, 1988; Grimm et al., 1993), the karstic river channels of North Florida contained much less water and the deeper sinkholes formed shallow spring-fed ponds that accumulated organic sediments. The sinkhole ponds and adjacent terrain became a refuge where wetland and more mesic vegetation survived Pleistocene climatic changes and variability, providing important habitat and water resources for a host of fauna, including large Pleistocene herbivores. Good evidence for this exists at the Page-Ladson site where the skeletal remains of both extinct and extant species of herbivores and other animals have been discovered along with intact deposits of late Wisconsin plant material, some of which we conclude represents the preserved fecal remains of herbivores that used the sinkhole as a watering hole and wallow during the latest Pleistocene. Based on the analyses reported in this chapter, the bulk of this material has been identified as the dung of Mammut americanum, the extinct American mastodon. Here we describe the composition of these dung deposits and the overall significance to mastodon foraging and behavioral ecology, including which plant taxa were selected or preferred as browse, what specific plant parts were consumed, the extent of damage large herbivores may have caused to plants in the foraging process, and what plants may have benefited from mastodon seed dispersal. The research has broader implications concerning how mastodons potentially influenced the ecology, structure, and evolution of woody plant communities in southeastern North America through their foraging activities. When compared to extant herbivore dung and known mastodon dung and stomach contents from other regions, the Page-Ladson dung reveals insights into the possible seasonal and regional fluctuations in the diet and migratory patterns of North American mastodons.