We birded down river from the city of Requena along Supay Creek the morning of Tuesday, January 17, 2012. I photographed this Green Iguana, Iguana iguana, because he was smiling at us. A large arboreal, mainly herbivorous species of lizard, it can grow to nearly five feet and weigh upwards of twenty pounds. In Peru this species appears bluish in color. A row of spines along the back and tail helps protect it from predators. A well developed dewlap (under the chin) helps it regulate body temperature (also used in courtship and territorial displays). A lateral nasal gland helps this lizard to secrete excess potassium and sodium chloride. The white tympanic membrane is visible below the mandibular joint. Temperatures were in the low 80's with overcast skies and high humidity.