The natural distribution of callimico goeldii comprises part of the Amazon basin in Colombia, Brazil, Peru and Bolivia.
They live in groups of 6-8 individuals and rest and sleep all together. Unlike other marmoset species, there is only one male per group that mates with all females.
The female gives birth to a baby weighing 30 - 80 grams after 155 days of gestation, which allows her to reproduce twice a year. During the first two weeks of life the mother carries the baby, the third week the father carries it and the fourth week the whole group assumes the responsibility of carrying it. They communicate among themselves by vocalizations, effective cries at more than 100m, smell and body language.
Their main threat is poaching for the black market, despite being an internationally protected species.
The Selwo Aventura group is part of the European Endangered Species Program (EEP) of the European Association of Zoos and Aquaria (EAZA).