Communication and Perception
Communication in Caretta caretta has not been well-studied. Courtship behavior seems to largely depend on visual and tactile cues, but it has been suggested that glandular odors (especially Rathke's gland secretions) may help bring the sexes together.
Perception, however, is highly developed. As soon as hatchlings emerge from their nests (usually at night), they begin analyzing their environment to determine which direction they should go towards the ocean. It is believed that a major clue is the light on the horizon. Hatchlings orient towards the brightest light, which, historically, is the moon or star light over the ocean. They may also perceive the incline of the beach and orient towards a lower elevation. Once in the water, hatchlings use chemical and magnetic cues to orient themselves and navigate their way to the currents in which they will spend the next 10 or so years of their lives.
During the juvenile and adult years it is likely that loggerheads use chemical and magnetic cues to orient themselves during their migrations. It has been demonstrated that C. caretta uses on-site cues, not memory of past movement, in orientation and is therefore capable of map-based navigation.
Food is typically located either visually or by smell.
Communication Channels: visual ; tactile ; chemical
Other Communication Modes: pheromones
Perception Channels: visual ; polarized light ; tactile ; vibrations ; chemical ; magnetic