The cotton-top tamarin (Saguinus oedipus) is a small New World monkey weighing less than . One of the smallest primates, the cotton-top tamarin is easily recognized by the long, white sagittal crest extending from its forehead to its shoulders. The species is found in tropical forest edges and secondary forests in northwestern Colombia, where it is arboreal and diurnal. Its diet includes insects and plant exudates, and it is an important seed disperser in the tropical ecosystem.
The cotton-top tamarin displays a wide variety of social behaviors. In particular, groups form a clear dominance hierarchy where only dominant pairs breed. The female normally gives birth to twins and uses pheromones to prevent other females in the group from breeding. These tamarins have been extensively studied for their high level of cooperative care, as well as altruistic and spiteful behaviors. Communication between cotton-top tamarins is sophisticated and shows evidence of simple grammatical structure.
Up to 40,000 cotton-top tamarins are thought to have been caught and exported for use in biomedical research before 1976, when CITES gave them the highest level of protection and all international commercial trade was prohibited. Now, the species is at risk due to large-scale habitat destruction, as the lowland forest in northwestern Colombia where the cotton-top tamarin is found has been reduced to 5% of its previous area. It is currently classified as critically endangered and is one of the rarest primates in the world, with only 6,000 individuals left in the wild.
Taxonomy and naming
S. oedipus has the common names "cotton-top tamarin" and "cotton-headed tamarin" in English. Its name comes from the white hair that spans its head and flows down past the neck.
The species was first described by Carl Linnaeus in his landmark 1758 10th edition of Systema Naturae. Despite this, both male and female infants prefers contact and proximity to their mothers over their fathers. Before 1976, when CITES listed the species under Appendix I banning all international trade, the cotton-top tamarin was exported for use in biomedical research.
In captivity, the cotton-top is highly prone to colitis, which is linked to an increased risk of a certain type of colon cancer. Up to 40,000 individuals were caught and exported for research into those diseases, as well as Epstein–Barr virus, for the benefit of humans. The species is now protected by international law. Although enough individuals are in captivity to sustain the species, it is still critically endangered in the wild.