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 models in malaria research.