The Douroucoulis, also called Night Monkeys and Owl Monkeys, as the name indicates, are active mainly at night.
They are small monkeys native to jungles/forests of Central and South America.
The several species of Night Monkey are divided into two groups, the grey-necked or northern, on this page page, with off-white or grey chest fur,
and the red-necked/southern (link below). Spix's Night Monkey, Aotus vociferans,
(shown above and immdiately below) is in the grey-necked group.
Spix's is native to southern Colombia, eastern Ecuador, part of far northern Peru and northwestern Brazil.
The Grey-handed Night Monkey, Aotus griseimembra,
is native to parts of northern Colombia and western Venezuela. Populations are vulnerable through habitat loss and (previous) capture for medical research.