In a poll to determine which of the world’s turtles would take home the people’s choice award, box turtles would win in a landslide. Sea turtles captivate observers around the globe, but few people get to know them. That is other than through the tedious exercise of keeping vigil as a female lays eggs at night on a coastal beach or watching as naturalists release a bucketful of hatchlings that immediately scamper into the waves and disappear. Of the 300-plus kinds of turtles on earth, people in the United States pick up more box turtles in natural habitats than any other kind of turtle. The most common are the eastern box turtle and a widespread western form known as the ornate box turtle.
For more than a century herpetologists have been conducting studies on box turtles. A frequent behavioral question is how far do they travel? Transmitters attached to the shell aid immensely in tracking the overland plodding of many turtle species, including box turtles. Movement patterns are of ecological importance in revealing which habitats are necessary for their long-term survival, including how many and how often turtles cross highways. For human-caused mortality, death-by-vehicle belongs near the top.
I. Lehr Brisbin of the University of Georgia’s Savannah River Ecology Laboratory conducted an intriguing study on movement patterns of box turtles in a suburban neighborhood. Over a single 3-year period one of the radio-tracked females was hidden in vegetation in the same backyard each time he checked. Others moved around extensively. Forty-two years later, Brisbin captured an adult box turtle that was still alive and roaming the neighborhood.
I recently learned of an innovative approach toward understanding movement patterns of box turtles by assaying the personalities of individuals. The unique study, undertaken by Benjamin Reed and his students at Washburn University, involves an assessment of three behavioral traits that could affect their ecology. In 2021 Reed determined the biopersonalities of more than a hundred ornate box turtles.
The first step was to classify each turtle in terms of three behavioral traits: boldness, activity level and tendency to explore. Variation among individual turtles was observed in all three behavior types. Some were clearly risk takers; others were notably more timid. Some were quantifiably more active than other more sedentary ones. Some were more likely to explore a new habitat; others chose to stick to an area already familiar to them.
The tests were well designed, with measurable levels for each of the three behavior types. To test for boldness, a box turtle was placed in a den (a safe refuge) that faced a video camera that would presumably be perceived as a threat. A turtle emerging quickly from the den was classed as a risk-taker. Those that took longer to emerge and those that did not leave at all fit the risk-averse category. Activity levels were tested by measuring how many revolutions a turtle made in a plastic wading pool over a given period of time. Some were constantly moving; others were mostly inactive or traveled infrequently. The exploration tendency was measured by providing small doorways leading to different compartments. Some test animals explored every available area, whereas some never left the first compartment they were in.
The experiments serve as proxies of turtle behavior. The real test will be if the behavior traits can be applied to what turtles do in the wild. So far, the findings have shown that bolder individuals move around more in their habitat. They presumably would encounter more feeding opportunities in the long term but also have a higher mortality rate. The next step is to determine if the findings for individuals apply to entire populations in an area. Are some bolder, more active, more exploratory than others? Ben Reed’s studies show great promise for revealing the ways turtle personalities may be useful in predicting how far an individual might travel and at the same time explaining why. For details on the study visit https://wu-turtle.weebly.com/.
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