Yellow-rumped Cacique is a widely distributed icterid, and is a common sight throughout lowland evergreen forests from Panama and Trinidad south to Peru, Bolivia, and central Brazil. This species primarily forages in the canopy along forest borders, such as along rivers, lakes, or other open areas such as fields. This diet is onmivorous; the cacique largely feeds on insects and other arthropods, but also consumes some fruit and nectar.
Yellow-rumped Cacique is very social, breeding in colonies that can range from 2-250 nests. Males are highly territorial and polygynous. Females build an enclosed, pouch-like, hanging nest that typically is place near Polistine wasp nests. This provides protection from mammals and botflies. Male dominance is determined by size and counter-singing. Song dialects are specific to individual colonies of Yellow-rumped Caciques. The male does not contribute to nest construction, incubation, or provisioning of the nestlingss.
Yellow-rumped Cacique also is sexually dimorphic in size and plumage. The male is larger and has brighter plumage than the female. Adults are mostly black but have a yellow wing coverts and a bright yellow patch on their rump. Males also have a short black crest, lacking in the female. Adult Yellow-rumped Caciques have pale blue eyes and a greenish yellow bill.