Winter Wolf - Fröhliche Weihnachten

A wolf walking on hard-crusted snow at night; a tree-covered peak in the background. Moonlight reflects off snow and pale bark of birch trees. The wolf's eyes also glow with reflected moonlight. German text reading "Fröhliche Weihnachten" appears in glowing blue and white. The reflective quality of many animals eyes is due to the tapetum lucidum (Latin: "bright tapestry; coverlet"), a layer of tissue immediately behind the retina, which reflects light back through the retina increasing the light available to the eye's photo-receptors. The existence of a tapetum lucidum contributes to the excellent night vision of many animals which are active at night such as nocturnal carnivores and deep sea creatures.