Chemo-orientation using conspecific chemical cues in the stripe-necked terrapin (Mauremys leprosa)

Although chemical communication has been studied intensively in may reptilian species, little attention has been paid to the role that chemical signals play in aquatic reptiles, such as freshwater turtles. Here, I tested the hypothesis that the stripe-necked terrapin (Mauremys leprosa), an abundant freshwater turtle that inhabits the Iberian peninsula, is able to recognize chemical cues from conspecifics in the water and to modify its behavior in response to such cues. I compared the time spent by adult males and adult females in clean water to the time spent in water that presumably contained their own odor, odor from other males, and odor from other females, both during and outside the mating season. Results show that outside the mating season, both males and females avoid water that contains chemical cues from conspecifics of the opposite sex. During the mating season, male turtles clearly select water with chemical cues from females. Moreover, males prefer to occupy water from their home containers over clean water, and avoid water with chemical cues from other conspecific males. Conversely, during the mating season, females prefer to occupy water with chemical cues from other females, but do not select water from their home containers or water from males. The evolution of chemical communication in turtles, its relation to sexual selection processes, and the implications for turtle behavior are discussed.