We birded down river from the city of Requena along Supay Creek the morning of Tuesday, January 17, 2012. I enjoyed watching the playful antics of a Pygmy Marmoset, Cebuella pygmaea, as it scampered in the canopy above us. This is the smallest monkey in the world. It has grayish, black mixed with buff or brownish-gold colored fur on the back, and white, tawny or orangish fur on its underparts. Its squirrel-like hands and feet have sharp claw-like nails (suited to clinging to trees and scratching the bark of the Uvos tree, Spondias mombin, to expose sap which they lick). The tail has indistinct dark rings. Temperatures were in the mid-80's with overcast skies and high humidity.