Reproduction:
Common Marmosets live together in family groups of four to 15 animals, usually mated adults and their offspring. These groups inhabit territories of 300,000 m2 (74 acres). The groups have a strict ranking, ordered by the dominance and aggressive behavior of the group leader.
Common Marmosets have variable mating systems: monogamous, polygynous and polyandrous. All adults and subadults share in the care of the young. After an approximately 150-day gestation, the female typically gives birth to twins, though up to four offspring have been observed in captive settings (larger litters suffer higher mortality rates). Compared to adults, the young animals are very large. Newborn twins together are 20 percent to 27 percent of the body weight of the mother, and it is assumed that the cooperative care of young helps counter some of the high costs of raising twin offspring. Males can mate after about one year, while females aren't fully mature until about 20 to 24 months.
Common Marmosets have variable mating systems: monogamous, polygynous and polyandrous. All adults and subadults share in the care of the young. After an approximately 150-day gestation, the female typically gives birth to twins, though up to four offspring have been observed in captive settings (larger litters suffer higher mortality rates). Compared to adults, the young animals are very large. Newborn twins together are 20 percent to 27 percent of the body weight of the mother, and it is assumed that the cooperative care of young helps counter some of the high costs of raising twin offspring. Males can mate after about one year, while females aren't fully mature until about 20 to 24 months.