The
night monkeys, also known as the
owl monkeys or
douroucoulis, are the members of the genus
Aotus of New World monkeys (monotypic in family
Aotidae). The only nocturnal monkeys, they are native to Panama and much of tropical South America. Night monkeys constitute one of the few monkey species that are affected by the often deadly human malaria protozoan
Plasmodium falciparum, making them useful as non-human primate experimental subjects in mala
(Wikipedia)