a1 Departamento Zoologia, Museu Paraense Emílio Goeldi, CP399, 66.000 Belém, Pará, Brazil.
a2 Subdepartment of Veterinary Anatomy, University of Cambridge, Tennis Court Road, Cambridge CB21QS, UK.
Until two decades ago, the only reference to the white uacari of the upper Amazon, known locally as the ‘English monkey’, had been provided by the British naturalist Henry Walter Bates, who saw captured animals during his sojourn in Amazonia in the 1850s. A major Brazilian initiative led us to the first intensive field study of the species, which was carried out in 1983 and 1984 by one of the authors, J. M. Ayres, with the participation of a large number of Brazilian scientists and a few from overseas. The study illustrated the uniqueness of the várzea habitat in which the animals live and the threats it currently faces. It also captured the attention of both the Brazilian scientific community and the public. Possibilities for the creation of a reserve area within the várzea are now being implemented.