Water anoles are remarkable creatures. Perched along the banks of steep waterfalls in the forests of Panama and Costa Rica, they're often seen bending and peering down at rushing streams below as if daring themselves to jump. They could, if they wanted to. With a natural scuba-like ability that lets them stay submerged for minutes, these lizards have long fascinated scientists. But new research reveals another subtler secret: Shifts in their skin color quietly signal their health and vitality.