Observations of Reptiles and Amphibians in a Louisiana Swamp

Abstract

Few studies have been made of the reptiles and amphibians of a swamp. Two of these are the studies of Wright (1932) in the Okefinokee swamp of Georgia and a population study of Thamnophis sauritus proximus by Tinkle (1957) in Louisiana. This report contains a summary of observations and experiments made with several species in a cypress-gum swamp near New Orleans in 1953 and 1954. The study was conducted on the Tulane University Sarpy Wildlife Refuge in St. Charles parish. The habitat has been described in detail by Tinkle (op. cit.), including a report regarding vegetational changes and fluctuations in water level. Most of these data were obtained on 31 visits to the study area between November, 1953, and December, 1954 and were sometimes incidental to the population study of the western ribbon snake referred to above. The water in the swamp is shallow (1-3 feet) except in borrow-pits traversing the refuge. There are open areas in the swamp resulting from timbering or representing abandoned oil well drilling sites. In these open areas cattail (Typha domingensis) and cutgrass (Zizaniopsis milliacea) predominate with pickerel weed (Pontederia cordata) in the shallow areas and water hyacinth (Eichornia crassipes) in the ditches. The swamp proper contains cypress (Taxodium distichum) and gum (Nyssa aquatica) with some ash (Fraxinus sp.) in the drier areas. Thickets of palmetto (Sabal minor) occur throughout the swamp. The dominant plants on the many ridges traversing the swamp are willow (Salix nigra), maple (Acer drummondii) and groundsel tree (Baccharis halimifolia) with blackberry (Rubus sp.) in the more open and disturbed areas. Many parts of the swamp were investigated, but most observations were made along a ridge, 25 feet in width and 600 yards in length. At the end of this ridge was an abandoned wellsite consisting of open water, cypress swamp, and marsh flats, several ridges and deep ditches. This site was divided into 90 quadrats with aluminum tape, each quadrat 15 feet square. This area will henceforth be referred to as the study area and the ridge leading to it as the main ridge. On each visit to the refuge notes were kept on the numbers of each species seen. On certain days attempts were made to survey and compare several areas within the swamp, to investigate in greater detail specific microhabitats, and to look for hibernating and egg-laying sites. The marking work was restricted to the study area although marked animals were searched for outside the quadrated area. All