This bird below is a Yellow-rumped Cacique which we were able to see early (very early) one morning outside a town on the Amazon river. My camera decided to choke on the autofocus modes unless the temperature was in a very tight range on this trip...so these are not a sharp photos. (I know, what a bad time for the autofocus to opt out!)
They nest in long pods of woven grass that hang from branches of trees that are usually close to marsh or lake edges. Being social and fairly common they can breed in colonies of up to 250 nests! Females do all the nest building, feeding and rearing. The male just fights for territory. They eat both insects and fruits. The males are polygamous and can consort with up to 30 females...since they only impregnate and fight for territory. By clustering together they also can defend themselves from predators by mobbing the enemy.