Spring emergence of Eastern Box Turtles (Terrapene carolina): influences of individual variation and scale of temperature correlates

Canadian Journal of Zoology, e-First Articles. Many organisms spend considerable time in dormancy to avoid stressful environmental conditions. Understanding the timing and triggers of dormancy behavior is critical for understanding an animal ’s life history and behavior. Eastern Box Turtles (Terrapene carolina (L., 1758)) avoid winter temperatures by burrowing into the soil and remaining dormant. Identifying the proximate environmental cues that trigger emergence can improve conservation efforts by reducing potential aboveground turtl e mortality. During a 17-year study, half of all variation in emergence timing was attributed to individual variation and the habitat that they occupied during dormancy. We suggest that individual variation in emergence timing is common within populations and confounds efforts to identify reliable e mergence cues. Additionally, the scale of meteorological data limits the ability to identify emergence predictors. Using data from temperature loggers placed at dormancy locations, we found that surface air temperatures, averaged over the 5 days prior to emergence, were more strongly related to emer gence probability than any variables derived from local weather stations. Turtles generally did not emerge from dormancy until the 5-day mean surface temperatures measured at dormancy sites reached approximately 15 °C. Our results suggest that individuals respond differently to environmental thresh olds for emergence and individuals may be characterize...
Source: Canadian Journal of Zoology - Category: Zoology Authors: Source Type: research