Retinal Ganglion Cells: Gerbils have specialized retinal ganglion cells that are sensitive to the direction of light. These cells are part of the retinohypothalamic tract (RHT) and play a crucial role in detecting the position of the sun.
Circadian Rhythm: Gerbils, like many mammals, have an internal biological clock known as the circadian rhythm. This rhythm regulates various physiological processes, including their activity-rest cycle and orientation.
Sun Compass: Gerbils use the sun as a compass to determine their direction. The retinal ganglion cells detect the position of the setting sun, and the gerbil aligns its body accordingly. By keeping the sun at a certain angle relative to its body, the gerbil can maintain the desired orientation during its navigation.
Landmarks: In addition to using the sun, gerbils also rely on landmarks in their environment for orientation. They use various visual cues, such as trees, rocks, or burrows, to create a mental map of their surroundings. This combination of using the sun and landmarks allows gerbils to navigate accurately in their natural habitats.
Adaptations: Gerbils have several adaptations that enhance their ability to orient in the setting sun. For instance, they have enlarged eyes to capture as much light as possible during dusk and dawn when the light is dim. Their eyes also have a high density of retinal ganglion cells that are sensitive to the direction of light.
Using the sun's position, in conjunction with their internal circadian rhythm and visual landmarks, gerbils can successfully navigate their surroundings, locate their burrows, and find food and water.
