There is only one breeding pair in a group (except the saddle-back tamarin where one female has multiple mates). Females become sexually mature at 18-24 months of age, males at 9-13 months. Births can occur in any month.
The gestation is about 140-170 days. The gestiation period of the golden lion tamarin is only about 132 days. Because of this short period they can produce 3 births in one year.
Most of the births take place at night.
They usually give birth to twins. Sometimes 1 or 4 monkeys are born. When more than 3 monkeys are born it may be necessary to remove some infants for hand-rearing. The golden lion tamarin is often able to rear three monkeys.
The weight of the infant depends on the specie. golden lion infant : appr 50-75g cotton-top infant : appr 34-52g (after 50 days appr 110g)
After 25 to 35 days the babies start to take some solid food. After a period of 100 days the youngsters are largely weaned. They sleep at the back of their parents until the age of 4 months.
Tamarins can live appr 15 years in captivity.