Crested Oropendola - Psarocolius decumanus
The male is glossy; lower back, rump and under tail coverts are dark chestnut, central tail feathers black, the others bright yellow. The female is considerably smaller and the black is duller.
Song a vaiable, descending, rattling gurgle, usually ending in a quavering liquid hooting phrase, then sometimes some rustling sounds 'glug t e t e e e e e OP wuubuubuub'.
The contact call is a wishtle "wheet"; there is also a variety of other whining and yapping calls.