Goeldi's Marmoset

Callimicos's geographic distribution extends from the Colombian Amazon and the Río Caquetá (Portuguese: Japurá) to the Peruvian and the western Brazilian Amazon, into the Pando department of northwestern Bolivia, where high densities have been reported. Its presence in Ecuador has yet to be officially confirmed. The distribution of the species is patchy, and its density seems to be dependent on polyspecific associations with tamarins. Sightings of Goeldi's marmosets have been made at the base of the Cordillera Oriental of the Andes in Colombia, in the Department of Putumayo, along the Putumayo and Caquetá Rivers. In Peru's northern interior, they occur in the Pucacuro National Reserve, close to the Río Tigre, where they are known as chi-chi by locals. To the south, they have been found at the Centro de Investigación y Capacitación Río Los Amigos (or Los Amigos River Training and Research Center, CICRA), Manu National Park, and the Concesión de Conservación Rodal Semillero Tahuamanu (CCRST), in addition to adjacent and surrounding areas. …

Females reach sexual maturity at 8.5 months, males at 16.5 months. The gestation period lasts from 144 to 159 days. Callimicos studied in captivity in North America and Europe for near 40 years have shown to produce on average 3.5 offspring during their lifetime. However, 30% of the females and 45% of the males observed in these settings never reproduced. Unlike other New World monkeys, they have the capacity to give birth twice a year. Biannual births occur regularly in captivity and less consistently in the wild and are attributed to postpartum estrus that allows the female to be ready to reproduce soon after parturition. The availability of fungus—an important food source for C. goeldii—throughout the year also contributes to these multiple births. The mother carries a single baby monkey per pregnancy, whereas most other species in the family Callitrichidae usually give birth to twins. These singleton births provide the offspring with longer maternal care and weaning delay that results in faster growth rates and in turn earlier sexual maturity than the other marmosets.