Ring-tailed lemurs are well-known for their thermoregulatory “sunning” postures, in which they sit upright with their forearms on their knees.
In the early mornings, usually between 5:30 and 8:30 a.m., ring-tailed lemurs move into the sun, away from their sleeping trees and onto exposed ground. There, they begin feeding and “sunning.”
The “sunning” posture is distinctive and stereotyped. Ring-tailed lemurs sit upright on their haunches, spread-eagle, and rest their forearms on their knees, exposing their undersides to direct sunlight. This behavior is probably linked to thermoregulation as it is often seen following cold nights or during cold mornings.