At first I wondered what these pudgy little brown birds were in a tree behind my cabin. Then on eBird’s Merlin I discovered that they are little White-collared Manakins with no white collar yet if male and if female that brown will turn green with a yellowish breast and the females don’t have white collars like the males. See more photos of these juveniles and my photos of mature males in the gallery White-collared Manakin (linked). I’ve seen them twice now at Maquenque and once at Selva Verde Lodge (across the river in their private forest reserve).
¡Pura Vida!