Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Eastern box turtle (Terrapene carolina carolina) growth and the impacts of invasive vegetation removal.

Abstract

Reptile growth is influenced by environmental, dietary, and genetic factors. Invasive vegetation alters both the thermal qualities of a habitat and food availability; therefore, removal of established invasive vegetation may impact turtle growth. We studied a population of Eastern Box Turtles (Terrapene carolina carolina) in Illinois, USA, to determine whether removal of invasive Autumn Olive (Elaeagnus umbellate) and Russian Olive (E. angustifolia) impacted instantaneous growth rates. Using 16-y of capture-mark-recapture data, we found no difference in instantaneous growth rate pre- and post-invasive vegetation removal. Most of the variation in growth was attributed to the individual. Comparing commonly used growth functions, sex-specific models were better than those not accounting for sex. Male carapace and plastron lengths grew faster than females. Extrapolating from growth curves and sizes at maturity, we estimate males mature at 8.2 y (95% CI = 5.0-13.3) and females mature at 7.8 y (95% CI = 4.7-21.9). Results from our study provide new insights about Eastern Box Turtle growth at the western edge of their distribution and show removing invasive woody vegetation may not negatively impact their growth.