Invasive plant species have the potential to disrupt growth patterns of native plant communities and alter ecosystem composition. Disruption of these habitats may affect behavior, movement, and physiology of the animal populations that inhabit them. Ectothermic vertebrates may especially be affected due to their reliance on specific habitat features for thermoregulatory purposes. By analyzing physiology, we can evaluate possible impacts on population health, including whether the presence of invasive plant species is a potential stressor. The heterophil to lymphocyte ratio (H:L) in blood can be an indicator of stress in vertebrates. To assess possible impacts of invasive Chinese privet (Ligustrum sinense) on Eastern Box Turtle (Terrapene carolina) H:L ratios in the North Georgia Piedmont region, we conducted a study to analyze this potential stressor on turtles that are currently a part of a larger, long-term radiotelemetry study. In June 2019, we drew blood samples from 16 radiotelemetered turtles and made blood smears in the field. Each smear was later stained using Wright-Giemsa stain. We categorized 100 leukocytes within each smear as either lymphocytes, heterophils, monocytes, or basophils, and calculated the H:L ratios. This data will be analyzed as related to individual sex, body size, and habitat use. Preliminary results of this study may highlight possible impacts on the indicators of stress of Eastern Box Turtles. Future research will continue through multiple seasons and years to expand sample size and continue assessing factors that may correlate with H:L ratios.
Key words: physiology; leukocytes; invasive species; turtles; habitat