The Aracá uakari (Cacajao ayresi), also known as the Ayres black uakari, is a new species of uakari from the northwest Brazilian Amazon. It was found by Jean-Phillipe Boubli of the University of Auckland after following native Yanomamo Indians on their hunts along the Rio Aracá, a northern tributary of the Rio Negro. It was subsequently described in 2008 together with the more westernly distributed Neblina uakari. Until then, the Golden-backed uakari was the only species of mainly black uakari that was recognized.