Twinning and Survivorship of Captive Common Marmosets (Callithrix jacchus) and Cotton-Top Tamarins (Saguinus oedipus)

Here we present the results of a demographic analysis of 25 y (1985 to 2010) of common marmoset (Callithrix jacchus) and cotton-top tamarin (Saguinus oedipus) records from the New England Primate Research Center. Summaries of longevity and survivorship are analyzed by birth-type category (including singletons, twins, triplets, and quadruplets) and sex. In addition, a brief evolutionary review is presented. Surrogates of hematopoietic chimerism, twinning, and reproductive output are explored in a large number of animals to help decipher the potential effects of chimerism on life history in marmosets and tamarins. In addition to exploring chimerism through demographic data, multiple-birth frequency and survivorship are compared between species. New World primates can make ideal translational models for disease and behavioral research across multiple disciplines. A better understanding of their reproductive success and survivorship in captivity helps develop these nonhuman primate models, their role in aging research, and understanding of their behavioral ecology. This mission is likely to only increase in its importance to biomedical research due to both the sequencing of the marmoset genome and the growing demand for alternatives to Old World primate models.Here we review demographic and life history data collected on common marmoset (Callithrix jacchus) and cotton-top tamarin (Saguinus oedipus) colonies housed at the New England Primate Research Center between 1985 and 2010. Information was gathered from a large database of 2753 C. jacchus and 2212 S. oedipus whose births were recorded over the 25 y. The cotton-top tamarin colony was established coincident with the founding of the center in the mid1960s. Initially used as a model system for biomedical research, the cotton-top tamarin was placed on the endangered species list in 1977, and invasive research was ended. The marmoset colony at our institution was established in late 1976 as an alternative model system, and attention in the tamarin colony turned to developing a better understanding of cotton-top tamarin health and reproduction. Several studies reflecting on this time discussed the factors influencing infant mortality and the veterinary practices to best minimize rejection.^11,12 This current work extends these studies to include animals born during the subsequent years and the entirety of the life histories of both marmosets and tamarins.