This dark-coated uakari is known from the Rio Curuduri and middle-to-lower Rio Araçá basins in Amazonas, Brazil. Its head, forelimbs, and front of the back are mostly black, while the rump, hind limbs, and tail are mostly dark brown. Few field records are available.
Among black-headed uakaris, C. ayresi has an especially uniform, dark coat. Black predominates on the head, mantle, and forelimbs; dark brown predominates on the saddle, rump, hind limbs, and tail. Black hairs are sparse on the chest and belly.
The 2015 Brazilian assessment summarizes only a few wild observations. One was in igapó forest with wetlands of Mauritia flexuosa palms; another was in a mosaic of terra-firme forest and open areas typical of the Rio Araçá basin. The report considers the taxon restricted to primary habitats; its tolerance of disturbance and home-range size are unknown.
An extinction-risk assessment has not been added yet.