Golden lion tamarins breed at any time of the year and keep to one partner. The gestation period is 5 months and usually twins are born. The male, as is usual in marmosets and tamarins, helps with the birth and takes the babies from the female and washes them. The new-born baby looks just like its parents but with shorter hair. It clings to its parent's body tightly with its hands and feet. The male is an excellent father, carrying his babies around for most of the time, handing one over to its mother every 2 to 3 hours; she suckles it for about 15 minutes and then hands it back to the male.
At about 3 weeks old, the youngsters start to explore their surroundings, darting back to their parents if alarmed. They will ride on the parents' backs until they are 6-7weeks old. At 4 weeks, the babies begin to eat soft food. The father may even peel and mash a banana in his hands to feed to them. They are capable of looking after themselves at 3-5 months but for some time they continue to run to their parents if danger threatens, and will beg food from them.
At 15 months of age, the tamarins are sexually mature and many young stay with their parents and live as extended families. The older youngsters often help with care of younger brothers and sisters.Read More: Golden Lion Tamarins and Humans