Golden lion tamarin

The golden lion tamarin, Leontopithecus rosalia, is a small New World monkey with a glowing reddish-orange coat and extra-long hair around the face and ears that forms a lion-like mane. Its face is dark and hairless. It is the largest of the callitrichid monkeys, the family of tamarins and marmosets, yet it is only about 26 centimetres long and weighs around 620 grams, and males and females are almost the same size.

It lives only in the Atlantic coastal forests of Brazil, entirely inside the state of Rio de Janeiro. The species is Endangered. A 2022 and 2023 census estimated about 4,800 wild animals in its main area. Its bright orange fur does not contain carotenoids, the pigments that make most orange colours in nature. Its Portuguese name is mico-leao-dourado.

Eating and moving

Golden lion tamarins eat mostly ripe fruit and small animals, plus some nectar and tree gum. They swallow most seeds, so they help spread many kinds of plants. In one study they ate 160 plant species. Their animal food includes frogs, lizards, spiders, insects and bird eggs.

They find hidden prey by poking their fingers, hands and even forearms into crevices, bromeliads and rolled leaves and feeling their way. They walk, run and bound along the tops of branches, and their claw-like nails help them climb straight tree trunks.

Family groups

Groups hold two to eight animals, usually one breeding pair and their young. Only the dominant female breeds. Females have mostly twins after a four-month pregnancy, and everyone in the group helps carry and raise the babies. In 2001 at Poco das Antas, 78 percent of births were twins.

The infants depend fully on their mother for four weeks, begin exploring around week five, become juveniles at 17 weeks, and become subadults at 14 months. Most new recruits to groups are males, and young animals can leave their birth group at about age four.

From 100 to thousands

Most of the original forest in Rio de Janeiro has been cleared, and the tamarins now live in forest fragments, such as the Poco das Antas and Uniao Biological Reserves and on private land. In the 1960s and 1970s there were only about 100 to 600 left.

The first census in 1990 to 1992 counted about 560 in the wild plus 100 released animals. Then zoo-born tamarins were reintroduced, wild ones were rescued, forests were replanted and joined up, and communities took part. The population grew to over 4,800, and the Golden Lion Tamarin Association keeps working on remaining threats.

On the globe

The model shows a golden lion tamarin with its glowing coat and lion-like mane in the Atlantic Forest of Brazil.