Temperament and sexual behaviour in the Furrowed Wood Turtle Rhinoclemmys areolata

The variation in temperament among animals has consequences for evolution and ecology. One of the primary effects of consistent behavioral differences is on reproduction. In chelonians some authors have focused on the study of temperament using different methods. In our research our first aim was i) establish a methodology to determine the degree of boldness among individuals Rhinoclemmys areolata. Our second aim was to ii) determine the role boldness plays during reproduction, with emphasis on courtship and copulation, considering a) the interactions between males and females, and b) competition between males. We used 16 sexually mature individuals of each sex. Males were observed in four different situations and 17 behavioral traits were recorded. We selected 12 traits that allowed us distinguish between the bolder and the shier individuals and found that five behavioral traits were specific for bolder individuals and five others for shier individuals. In a second step, we observed a male in presence of a female and recorded courtship behaviors and breeding attempts. Bolder individuals did not display courtship behaviors and just attempted to copulate. Shier individuals displayed courtship behaviors and copulation attempts were rarely observed. Finally, in the simulations that compared two males in the presence of a female we noticed that bolder individuals displayed courtship behaviors while the shier ones simply ignored the female. Our results first allowed us to determine which methodology is the best to determine temperament in turtles. Secondly, temperament seems to be an important factor in modulating interaction between males and females. Bolder individuals have an advantage during competition and display courtship behaviours only if other males are present. Shier males displayed courtship behaviors and only try to copulate when no competitors were present. These two different temperament-dependant strategies are discussed in terms of ecology, evolution and management.

Wood Turtle (Glyptemys insculpta) nest protection reduces depredation and increases success, but annual variation influences its effectiveness

Habitat loss is the leading cause of species extinctions and is especially detrimental to habitat specialists. Freshwater turtles require specific habitat types at different points in their life cycle; notably, the loss of nesting habitat has led to increased nest depredation and adult mortality. In response, conservationists have implemented nest protection and habitat restoration programs to recover declining populations. Although assumed to increase nest survival, effectiveness of these methods has not been rigorously quantified. We located Wood Turtle (Glyptemys insculpta (Le Conte, 1830)) nests in Wisconsin (USA) and conducted two analyses — logistic regression and logistic exposure — to investigate the influence of management actions and environmental factors on nest survival. The depredation rate decreased by 47% for protected nests and declined as nests aged; the success rate increased by 28% for protected nests and increased for nests in areas with fewer roads. We found high annual variation in success, and although weather variables were not predictive, likely due to their coarse scale, we posit that this inter-annual variation was driven by variation in weather conditions. Our results suggest that nest protection is effective at increasing nest survival, but future efforts should span multiple years to account for the effects of annual variation in environmental conditions.

GPS Technology for Semi-Aquatic Turtle Research

Global positioning system (GPS) telemetry units are now small enough to be deployed on terrestrial and semi-aquatic turtles. Many of these GPS units use snapshot technology which collects raw satellite and timestamp data during brief periods of data recording to minimize size. We evaluated locations from snapshot GPS units in stationary tests and on wood turtles (Glyptemys insculpta) in northeastern Minnesota. Stationary GPS units were placed in wood turtle habitat to evaluate location accuracy, fix success rate, and directional bias. The GPS fix success rate and accuracy were reduced in closed canopy conditions and when the stationary GPS unit was placed under a log to simulate wood turtle hiding behavior. We removed GPS location outliers and used a moving average calculation to reduce mean location error in stationary tests from 27 m (SD = 38) to 10 m (SD = 8). We then deployed GPS units and temperature loggers on wood turtles and collected 122,657 GPS locations and 242,781 temperature readings from 26 turtles from May to September 2015 and 2016. Location outliers accounted for 12% of locations when the GPS receiver was on a turtle. We classified each wood turtle location based on the GPS location and by comparing temperature profiles from river, sun, and shaded locations to the temperature logger on the turtle. We estimated that wood turtles were on land 68% (SD = 12) of the time from May to September. The fix success rate for land locations was 38% (SD = 9), indicating that wood turtles often use habitats with obstructed views of the sky. Mean net daily movement was 55 m (SD = 192). Our results demonstrate that snapshot GPS units and temperature loggers provide fine-scale GPS data useful in describing spatial ecology and habitat use of semi-aquatic turtles.