Ecology of the Basking Habit in Turtles

A combined field and laboratory study was conducted to assess the biological implications of the basking habit in turtles. The effect of light intensity and incidence angle, water and air temperatures, wind, and cloud cover upon rates of heat gain in turtles were investigated, and all were found to have importance. Biological factors of importance are behavior, shape, weight, and rarely, color; sex and species were not important except as they affect the other factors. A series of motivation studies was conducted to identify the environmental factors initiating and directing basking. The taxonomic incidence of the basking habit in turtles is discussed. Basking serves primarily as a method of thermal control, with secondary benefits in drying of the skin and shell.