It is only very recently that humans have been able to obtain any information about this species at all. Because of their rarity and size, they are difficult to study in the wild, and comparisons between captive and field studies have proved that their behavior varies between the two. (Evans, 1986)
Maximum longevity: 16.5 years (captivity) Observations: These animals appear to be amongst the fastest ageing primates (Austad 1997). One female lived 16.5 years in captivity (http://ipad.primate.wisc.edu/). In addition, one male specimen reportedly lived 22.8 years in captivity (Richard Weigl 2005). Although possible, because there are no other known cases of common marmosets living over 16.5 years, the accuracy of this report is considered questionable.
It was originally thought that common marmosets were monogamous creatures, forming pair bonds and raising their offspring as a team. This was believed because captive marmosets only bred successfully in a pair situation. However, it has recently been discovered that the common marmoset, along with other species of marmosets and tamarins, is actually polyandrous (one female mates with multiple males). In the wild, groups of two males and a female form in order to mate and rear offspring. The female mates nearly equally with both males while in estrus.
Mating System: polyandrous ; cooperative breeder
After gestating for approximately 148 days, the female gives birth to the offspring, usually twins (Smuts et al., 1987).
Average age at sexual or reproductive maturity (male) Sex: male: 382 days.
Average age at sexual or reproductive maturity (female) Sex: female: 477 days.
The twins combined can equal up to 40% of the female's body weight. The males assist the female in carrying the infants, and it is generally thought that polyandry in this species is due to the large size of these babies and the energy needed to raise them.
Common marmosets are one of the most endangered callitrichid species. The complete destruction of their habitat in north eastern Brazil has severely threatened the species, but their numbers in reserves in south eastern Brazil seem to be growing.
(Smuts et al., 1987)
IUCN Red List of Threatened Species: least concern
Rylands, A.B, Mittermeier, R.A., de Oliveira, M.M. & Kierulff, M.C.M.
Mittermeier, R.A., Rylands, A.B. (Primate Red List Authority) & Hoffmann, M. (Global Mammal Assessment Team)
This species is listed as Least Concern as it is relatively widely distributed, adaptable, occurs in a number of protected areas, and because the current rate of decline is not sufficient to qualify it for a threatened category.
Although widespread and common in many localities, and even replacing other Callithrix species where it has been introduced, C. jacchus populations are declining through habitat destruction in many parts of their distribution (Mittermeier et al. 1988; Coimbra-Filho 1984). There is some limited hunting for pets.