Goeldi's marmoset

The Goeldi's marmoset, also known as the Goeldi's monkey, is a charming primate native to the upper Amazon basin, covering areas in Bolivia, Brazil, Colombia, Ecuador, and Peru. This species is unique as the sole member of its genus, Callimico, and is sometimes affectionately referred to as "callimicos."

These monkeys display a blackish or dark brown coat, often highlighted with striking red, white, or silvery brown tones on their heads and tails. They are quite petite, with body lengths ranging from 8 to 9 inches, complemented by tails that extend an additional 10 to 12 inches.

First described in 1904, the Goeldi's marmoset has experienced a dynamic history in taxonomy. Initially, it was classified in its own family, Callimiconidae, or sometimes in the subfamily Callitrichinae within the family Cebidae. Today, scientists have promoted Callitrichinae to full family status as Callitrichidae, where Goeldi's marmoset now resides.

Regarding reproduction, female Goeldi's marmosets reach sexual maturity at around 8.5 months, while males mature slightly later at 16.5 months. They have a gestation period of 140 to 180 days and can give birth twice a year, typically to a single offspring each time. The young are weaned after about 65 days. In captivity, these monkeys can live up to 10 years and are renowned for their impressive jumping abilities.

Goeldi's marmosets thrive in dense undergrowth, where they forage for a varied diet that includes fruit, insects, spiders, lizards, frogs, snakes, and even fungi. They live in small, close-knit social groups and communicate with each other through high-pitched calls. Interestingly, they sometimes form mixed groups with tamarins.

The species is named in honor of Emil August Goeldi, a Swiss naturalist who made significant contributions to the study of South American wildlife. Despite their rarity, these little monkeys continue to captivate those fortunate enough to observe them in their natural habitat.