Francois' langur: Very rare, very cute, bright orange monkey born at Sydney's Taronga Zoo

Taronga Zoo in Sydney is celebrating the birth of a bright orange Francois' langur, one of the world's rarest monkeys. Keepers have named the male infant 'Nangua' after the Mandarin word for pumpkin. He was discovered cradled in mother Meili's arms on 7 November.

Francois' langurs, also known as Francois' leaf monkeys, are born with bright orange hair while adults are black. It is thought this colour distinction makes it easier for the adults to identify and look after the babies.

Taronga Zoo's senior primate keeper, Jane Marshall, said Nangua was already receiving lots of attention from his mother and the harem group's other females, Noel and Elke. "Meili has shown her calmness and experience since the birth, cradling and protecting the baby, but also allowing Noel and Elke to get close to him," said Jane.

Francois' langurs practice allomothering or 'auntying', in which other females participate in raising the baby. Infants can often be seen being passed around as each of the langurs take turns caring for the new arrival. "Noel has taken on the role of allomother, carrying the baby about 50% of the time. This gives mum a break to eat and rest, but as soon as the baby whimpers she races straight back over to him," said Marshall.

Nangua has begun to explore his exhibit in Taronga's Rainforest Trail to the delight of visitors. The infant is the second for Meili at Taronga, following the birth of a male named Tam Dao in 2011, and the first for father Bobo, who arrived at Taronga from Beijing Zoo in 2010, as part of the international breeding programme for the endangered species.

Once widespread in China and Vietnam, Francois' langurs have become one of the world's rarest monkeys due to habitat loss and poaching for traditional medicines. There are believed to be fewer than 500 left in Vietnam and around 1,500 in China.