The morning of Tuesday, January 17, 2012, we birded along the Ucayali River and along Supay Creek, which is located down river from the city of Requena. The noisy 'chacks' of a colony of Yellow-rumped Caciques, Cacicus cela, quickly attracted our attention to the forest edge (várzea) as we rounded a bend in the Supay. The pendulous hanging basket type of nests were concentrated in one tree with Caciques flying and displaying. Temperatures were in the low 70's with overcast skies and high humidity.