Diurnal

Diurnal animals typically rely more on color vision — many birds and primates have trichromatic color vision enabling them to find ripe fruit and identify conspecifics by plumage or skin color. Activity at the intersection of day and night (crepuscular) captures the benefits of both. The circadian rhythm — an internal 24-hour clock — synchronizes physiological processes with the light-dark cycle in virtually all living organisms.