The cotton-top tamarin (Saguinus oedipus), is a small New World monkey weighing less than 1 lb (0.5 kg). 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 Northern Colombia where it is arboreal and diurnal.
Cotton-top tamarins display a wide variety of social behaviors. In particular, groups form a clear dominance hierarchy where only dominant pairs breed. These tamarins have been extensively studied for their high level of cooperative care, as well as altruistic and spiteful behaviors.