An Experimental Release of Elk into Great Smoky Mountains National Park
Date of Award
Doctor of Philosophy
Joseph D. Clark
Frank van Manen, Lisa Muller, Edward Ramsay, Mike Jenkins
I conducted 6 years of field work to evaluate the habitat use and population dynamics of an experimental release of elk (Cervus elaphus) into Great Smoky Mountains National Park (Park). Elk exhibited relatively small home ranges (female: 10.4 km2 and males: 22.4 km2) and movement distances decreased over time. I calculated survival rates (x = 0.73–0.93) and litter production rates (x = 0.73) for the population. To assess the potential for a long-term elk population, I incorporated those vital rates into the population modeling software Riskman and tested its sensitivity to any given vital rate. The projected population growth was positive (1.03, SD = 0.001) and the probability of extinction in 100 years was minimal (1%, SD = 0.001). However, the model was sensitive to adult female survival, and the simulated annual deaths of only 4 adult females increased the probability of extinction to 45% (SD = 0.021). Compositional analysis detected a strong preference for grassland areas by elk in the Park. I used spatial data to identify potential habitat for elk on a multivariate level by calculating the Mahalanobis distance (D2) statistic based on the relationship between elk locations and 7 landscape variables. The D2 model indicated that the best elk habitat primarily occurred in areas of moderate landscape complexity and edge denisty and gentle slope, and was limited in the Park. At the current small population density, elk had minimal impact on vegetation inside the Park and their diet consisted primarily of graminoids. The elk population at Great Smoky Mountains National Park will likely remain small and vulnerable to extinction for some time due to low growth rates, high environmental stochasticity, and limited habitat. Active management (e.g. predator management, prescribed burning, and mowing) will be required to maintain this population until the population grows to more sustainable levels.
Murrow, Jennifer Lynn, "An Experimental Release of Elk into Great Smoky Mountains National Park. " PhD diss., University of Tennessee, 2007.