Oropendolas are colonial nesters. That means a group of them build their nests in close proximity, possibly all in one tree. Females build a woven, hanging nest which looks like a giant Oriole’s nest. The nest can be from 24 to 72 inches long. One male will be dominant in the colony and will mate with most of the females. A typical colony will have about 30 nests, but up to 172 have been seen in a single colony.