Matt Smith, Mammal Diversity in the North Chickamauga Creek George State Natural Area and the Effects of Internal Fragmentation on the Relative Distributions of Mammalian Carnivores
Faculty Chair: Dr. David Aborn
Mammal species were surveyed in North Chickamauga Creek Gorge State Natural Area using various methods of observation. Sixteen mammal species were detected in the natural area, 14 of which were previously undocumented. The white footed mouse and the raccoon were the most abundant species. These are additional mammal species that may occur in the natural are but were not documented during this survey. Future surveys should place an emphasis on locating these species. The natural are will become more important for maintaining biodiversity as development proceeds in the surrounding area. However, the success of the natural area can only be assessed once all the species have been identified and monitoring programs are put into place.
The effects of internal habitat fragmentation caused by transmission line right-of-way on the relative distributions of mammalian predators were studies in the North Chickamauga Creek Gorge State Natural Area in preliminary and primary investigations. Larger mammalian carnivores were predicted to be more concentrated in the transmission line right-of-way, whereas small to medium-sized mammalian predators (i.e., mesopredators) were predicted to be more concentrated in the adjacent forested areas.
For the preliminary investigation, five transects containing scent stations were constructed in and surrounding the right-of-way. The tracks of 13 large mammalian carnivores and 39 mesopredators were detected. No significant differences were detected in the distributions of either the large mammalian carnivores or the mesopredators. However, there were noticeable trends that warranted further investigation.
For the primary investigation, a series of six transects containing aluminum track plates was constructed in and surrounding the right-of-way. The tracks of 14 large mammalian carnivores and 36 mesopredators were detected. The large mammalian carnivores exhibited a strong preference for the transmission line right-of-way consistent with predictions. In contrast, the mesopredators were distributed more uniformly, yielding no significant differenced in their distributions. The higher- than-expected occurrence of mesopredators in the right-of-way may have been temporal variations caused by dietary enhancements during particular times of the year.
Top carnivores, although few in numbers are important in structuring biological communities. In particular, they limit the effects of mesopredators on the broader ecological community. In the natural area, these relationships should be maintained by the presence of top carnivores. However, more research is needed to confirm this in order to ensure that biodiversity is preserved in accordance with the goals of the natural area.