Grey-legged night monkey  (Aotus griseimembra)

Being nocturnal not only reduces the threat of natural predation but also significantly protects the grey-legged night monkey from hunting by humans. Whilst many monkey species are killed and captured for sport, food, ‘traditional medicine' and to become pets, night monkeys' reclusiveness provides them with some sanctuary. Nonetheless, they are not entirely safe from human interference as they are the best primate model for medical research into malarial vaccines. Many humans are infected with, and die from, malaria each year. This species is particularly suited to malarial research due to its high susceptibility to both forms of malaria-causing Plasmodium parasites, and the similarity of its immune system with that of humans. It is also used to test anti-malarial drugs (6). There is much controversy as to whether it is justifiable to continue taking this threatened species from the wild for the protection of humans, and whilst it can be bred in captivity, individuals are occasionally taken from the wild to prevent inbreeding depression in captive populations (4).

Habitat destruction and disturbance are also threats, but the relatively high level of isolation in Colombia's forests affords it some protection (7).

The listing of the grey-legged night monkey on Appendix II of the Convention on International Trade in Endangered Species of Fauna and Flora has placed limitations on the numbers allowed to be exported from Colombia to countries conducting medical research. Whilst this has implications on the efficiency and value of medical research into malaria vaccines, it may simply result in the development of malaria research facilities in Colombia, thereby preventing the need for export of grey-legged night monkeys, but continuing their removal from the wild (6) (8).

Colombia was the subject of a debt-for-nature swap coordinated by the WWF and The Nature Conservancy, and using funds from the United States Government and the Global Conservation Fund. Millions of U.S. dollars will be released to five conservation sites in Colombia over a 12-year period, in return for the cancellation of a large amount of national debt. This scheme prevents the inevitable loss of funding for environmental projects that occurs as governments slip further into debt, and puts the funds back into environmental enhancement programs, such as the creation of protected areas (9).