Elk in the Old Dominion: Abundance, Demographics, and Drivers of Space Use and Habitat Selection

Abstract

In order to reintroduce and establish an elk population, the Virginia Department of Wildlife Resources (formerly Virginia Department of Game and Inland Fisheries) implemented soft releases of 75 elk (Cervus canadensis) translocated to southwestern Virginia from eastern Kentucky during 2012, 2013, and 2014. Achieving a target population size is often the initial goal of species restoration. Further, understanding how reintroduced populations acclimatize to novel environments can lend insight into social learning that in turn is valuable for assessing reintroduction success and maximizing efficacy of subsequent efforts. To investigate the progress of Virginia's reintroduced elk population and how elk responded to the landscape, I covered two main topics: 1) elk abundance and herd demographics and 2) elk space use, habitat quality, and resource selection. To assess post-release population size and herd demographics, I conducted visual driving surveys throughout Buchanan County during January – March/April in 2021, 2022, and 2023. During surveys, I counted elk and noted sex, age class, and tagged individuals, as well as location of the observations. With the data collected from these surveys, I estimated yearly cow:calf:bull ratios and non-spatially and spatially informed population estimates. Non-spatial population estimates were minimum counts and Lincoln-Petersen Indices with the Chapman's Bias Correction. Spatial estimates utilized both Spatially Explicit Capture Recapture and Spatial Mark Resight techniques. I found spatial estimates were more viable than Lincoln-Petersen with less survey effort, whereas simpler Lincoln-Petersen methods were more viable than spatial estimates with greater survey effort. To quantify elk space use, I utilized global positioning system collar data from elk following their release and subsequent captures from 2019 through 2022. With this movement data, I determined seasonal space use was the smallest during winter, likely in an effort to conserve energy when resources are most scarce. My analyses of habitat quality and resource selection revealed that throughout the year, reclaimed surface mines and gentler topography were selected by elk, indicating higher habitat quality, whereas deciduous forests were consistently avoided. My findings illuminated important considerations for successful reintroductions. First, I demonstrated viable options for estimating population abundance with different survey efforts. Second, I found spatial and temporal variation in habitat quality demonstrated the importance of non-forested habitats to elk, which can guide decisions regarding the location of future elk reintroduction programs and serve as a model for evaluating habitat quality associated with wildlife reintroductions.